497

This Prospectus describes Janus Henderson Balanced Portfolio (the “Portfolio”), a series of Janus Aspen Series (the “Trust”). Janus Henderson Investors US LLC (the “Adviser”) serves as investment adviser to the Portfolio. The Portfolio currently offers two classes of shares. The Service Shares (the “Shares”) are offered by this Prospectus in connection with investment in and payments under variable annuity contracts and variable life insurance contracts (collectively, “variable insurance contracts”), as well as certain qualified retirement plans.

This Prospectus contains information that a prospective purchaser of a variable insurance contract or plan participant should consider in conjunction with the accompanying separate account prospectus of the specific insurance company product before allocating purchase payments or premiums to the Portfolio. Each variable insurance contract involves fees and expenses that are not described in this Prospectus. Refer to the accompanying contract prospectus for information regarding contract fees and expenses and any restrictions on purchases or allocations.

For the purpose of this Prospectus, any reference to the “Janus Henderson funds” is inclusive of all series of the Trust, collectively, unless otherwise noted in this Prospectus.

Portfolio summary

Janus Henderson Balanced Portfolio

Ticker:

N/A

Service Shares

Investment Objective

Janus Henderson Balanced Portfolio (“Balanced Portfolio”) seeks long-term capital growth, consistent with preservation of capital and balanced by current income.

Fees and Expenses of the Portfolio

This table describes the fees and expenses that you may pay if you buy, hold, and sell Shares of the Portfolio. Owners of variable insurance contracts that invest in the Shares should refer to the variable insurance contract prospectus for a description of fees and expenses, as the following table and examples do not reflect deductions at the separate account level or contract level for any charges that may be incurred under a contract. Inclusion of these charges would increase the fees and expenses described below.

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		0.55%
Distribution/Service (12b-1) Fees		0.25%
Other Expenses		0.07%
Total Annual Fund Operating Expenses		0.87%

EXAMPLE:

The Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated, reinvest all dividends and distributions, and then redeem all of your Shares at the end of each period. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years	5 Years	10 Years
Service Shares	$ 89	$ 278	$ 482	$ 1,073

Portfolio Turnover: The Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’s turnover rate was 83% of the average value of its portfolio.

Principal investment strategies

The Portfolio pursues its investment objective by normally investing 35-70% of its assets in equity securities and the remaining assets in fixed-income securities and cash equivalents. The Portfolio normally invests at least 25% of its assets in fixed-income senior securities. As of December 31, 2024, approximately 62.91% of the Portfolio’s assets were held in equity securities, including common stocks, and 37.09% of the Portfolio’s assets were held in fixed-income securities and cash equivalents.

The Portfolio’s equity investments include, but are not limited to, common stocks and other securities with equity characteristics. The Portfolio’s fixed-income investments include, but are not limited to, government notes and bonds, corporate bonds, commercial and residential mortgage-backed securities, and asset-backed securities. The Portfolio may also invest in money market instruments. The Portfolio may invest in fixed and floating rate obligations with varying durations.

The Portfolio will limit its investments in high-yield bonds (also known as “junk” bonds) to 35% of the fixed-income portion of its net assets. The Portfolio may enter into “to be announced” or “TBA” commitments when purchasing mortgage-backed

2 | Janus Henderson Balanced Portfolio

securities or other securities. The Portfolio also invests in securities that have contractual restrictions that prohibit or limit their public resale, which may include Rule 144A securities.

The Portfolio may also invest its assets in derivatives, which are instruments that have a value derived from, or directly linked to, an underlying asset, such as fixed-income securities, currencies, interest rates, or market indices. In particular, the Portfolio may use interest rate swaps and futures, including Treasury bond futures, to manage interest rate risk, yield curve positioning, and country exposure. The Portfolio may also use index credit default swaps for hedging purposes (to offset risks associated with an investment exposure or market conditions), to increase or decrease the Portfolio’s exposure to a particular market, to manage or adjust the risk profile of the Portfolio relative to its benchmark index, and to earn income, enhance returns, or preserve capital. The Portfolio’s exposure to derivatives will vary and may include derivatives that have characteristics similar to the securities in which the Portfolio may directly invest. The Portfolio may take short positions on derivatives instruments.

In choosing equity investments, portfolio management applies a “bottom-up” approach. In other words, equity portfolio management looks at companies one at a time to determine if a company is an attractive investment opportunity and if it is consistent with the Portfolio’s investment policies. Factors that equity portfolio management will consider in its fundamental analysis include a company’s revenue growth potential, returns on capital, and balance sheet flexibility. Equity portfolio management will generally consider selling a security when, among other things, it reaches or exceeds its targeted value, the investment thesis for owning the position has changed, or to rebalance industry or sector weightings.

In choosing fixed-income investments, portfolio management’s investment process is research-driven, incorporating “top-down” and “bottom-up” factors to identify and manage exposure to risks across sectors, industries, and individual investments. Fixed-income portfolio management evaluates expected risk-adjusted returns on a portfolio and position level by analyzing fundamentals, valuations, and market technical indicators. This research encompasses both traditional fundamental analysis and data driven quantitative models and signals from such models.

As part of its investment process, portfolio management considers environmental, social, and governance (“ESG”) risks and opportunities (“ESG Factors”) that it believes are financially material, alongside other fundamental investment factors. Examples of potential financially material ESG Factors include: corporate governance, company culture, exposure to climate change, and human capital management. To assess ESG Factors, portfolio management uses issuer reports, third-party data, and internally-generated analyses and may engage directly with issuers. ESG Factors are one of many considerations in the investment decision-making process, may not be determinative in deciding to include or exclude an investment from the portfolio, and may not be considered for every investment decision.

Principal investment risks

The biggest risk is that the Portfolio’s returns will vary, and you could lose money. The Portfolio is designed for long-term investors seeking a balanced portfolio, including common stocks and bonds. The principal risks associated with investing in the Portfolio are set forth below.

Market Risk. The value of the Portfolio’s holdings may decrease due to short-term market movements and over more prolonged market downturns. As a result, the Portfolio’s net asset value may fluctuate and it may be more difficult to value or sell the Portfolio’s holdings. Market risk may affect a single issuer, industry, economic sector, or the market as a whole. Market risk may be magnified if certain social, political, economic, and other conditions and events (such as financial institution failures, economic recessions, tariffs, trade disputes, terrorism, war, armed conflicts, including related sanctions, social unrest, natural disasters, and epidemics and pandemics) adversely interrupt the global economy and financial markets. It is important to understand that the value of your investment may fall, sometimes sharply, in response to changes in the market, and you could lose money.

3 | Janus Henderson Balanced Portfolio

Equity Securities Risk. Equity securities are subject to changes in value, and their values may be more volatile than those of other asset classes. The value of the Portfolio’s holdings may decrease if the value of an individual company or security, or multiple companies or securities, in the portfolio decreases. Further, regardless of how well individual companies or securities perform, the value of the Portfolio’s holdings could also decrease if there are deteriorating economic or market conditions or perceptions regarding the industries in which the issuers of securities the Portfolio holds participate.

Fixed-Income Securities Risk. Fixed-income securities are generally subject to the following risks:

•

Interest rate risk, which is the risk that prices of bonds and other fixed-income securities will increase as interest rates fall and decrease as interest rates rise. Changing interest rates have unpredictable effects on the markets and may expose fixed-income and related markets to heightened volatility.

•

Credit risk, which is the risk that the credit strength of an issuer of a fixed-income security will weaken and/or that the issuer will be unable to make timely principal and interest payments and that the security may go into default.

•

Prepayment risk, which is the risk that, during periods of falling interest rates, certain debt obligations may be paid off quicker than originally anticipated, which may cause the Portfolio to reinvest its assets in securities with lower yields, resulting in a decline in the Portfolio’s income or return potential.

•

Extension risk, which is the risk that, during periods of rising interest rates, certain debt obligations may be paid off substantially slower than originally anticipated, and as a result, the value of those obligations may fall.

•

Valuation risk, which is the risk that one or more of the fixed-income securities in which the Portfolio invests are priced differently than the value realized upon such security’s sale. In times of market instability, valuation may be more difficult. Valuation may also be affected by changes in the issuer’s financial strength, the market’s perception of such strength, or in the credit rating of the issuer or the security.

•

Liquidity risk, which is the risk that fixed-income securities may be difficult or impossible to sell at the time that portfolio management would like or at the price portfolio management believes the security is currently worth. Consequently, the Portfolio may have to accept a lower price to sell a security, sell other securities to raise cash, or give up an investment opportunity, any of which could have a negative effect on the Portfolio’s performance. In unusual market conditions, even normally liquid securities may be affected by a degree of liquidity risk (i.e., if the number and capacity of traditional market participants is reduced).

Dividend-Oriented Stocks Risk. Companies that have paid regular dividends to shareholders may decrease or eliminate dividend payments in the future. A decrease in dividend payments by an issuer may result in a decrease in the value of the security held by the Portfolio or the Portfolio receiving less income.

High-Yield Bond Risk. High-yield bonds (also known as “junk” bonds) are considered speculative and may be more sensitive than other types of bonds to economic changes, political changes, or adverse developments specific to the company that issued the bond, which may adversely affect their value.

Portfolio Management Risk. The Portfolio is an actively managed investment portfolio and is therefore subject to the risk that the investment strategies and research process employed for the Portfolio may fail to produce the intended results. Accordingly, the Portfolio may underperform benchmark indices or other funds with similar investment objectives.

Mortgage- and Asset-Backed Securities Risk. Mortgage- and asset-backed securities represent interests in “pools” of commercial or residential mortgages or other assets, including consumer loans or receivables. The value of mortgage- and asset-backed securities will be influenced by factors affecting the real estate market and the assets underlying these securities. Investments in mortgage-and asset-backed securities may be subject to credit risk, valuation risk, liquidity risk, extension risk, and prepayment risk. These securities also are subject to risk of default on the underlying mortgage or asset, particularly during periods of economic downturn.

Sovereign Debt Risk. Investments in U.S. and non-U.S. government debt securities (“sovereign debt”), especially the debt of certain emerging market countries, can involve a high degree of risk, including the risk that the governmental entity that controls the repayment of sovereign debt may not be willing or able to repay the principal and/or to pay the interest on its sovereign debt in a timely manner. A sovereign debtor’s willingness or ability to satisfy its debt obligation may be affected by various factors including, but not limited to, its cash flow situation, the extent of its foreign currency reserves, the availability of foreign exchange when a payment is due, and the relative size of its debt position in relation to its economy as a whole. In the event of default, there may be limited or no legal remedies for collecting sovereign debt and there may be no bankruptcy proceedings through which the Portfolio may collect all or part of the sovereign debt that a governmental entity has not repaid. In addition, to the extent the Portfolio invests in non-U.S. sovereign debt, it may be subject to currency risk.

4 | Janus Henderson Balanced Portfolio

Derivatives Risk. Derivatives can be volatile and involve risks in addition to the risks of the underlying referenced securities or asset. Gains or losses from a derivative investment can be substantially greater than the derivative’s original cost, and can therefore involve leverage. Leverage may cause the Portfolio to be more volatile than if it had not used leverage. Derivatives entail the risk that the counterparty may default on its payment obligations. If the counterparty to a derivative transaction defaults, the Portfolio may lose the net amount of the payments that it contractually is entitled to receive. Derivatives used for hedging purposes may reduce or eliminate gains or cause losses if the market moves in a manner different from that anticipated by portfolio management or if the cost of the derivative outweighs the benefit of the hedge.

Floating Rate Obligations Risk. The Portfolio may invest in floating rate obligations with interest rates that reset regularly. The interest rates on floating rate obligations typically reset quarterly, although rates on some obligations may adjust at other intervals. Changes in the interest rates on floating rate obligations could result in lower income to the Portfolio. In addition, the secondary market on which floating rate obligations are traded may be less liquid than the market for investment grade securities or other types of income-producing securities, which may have an adverse impact on their market price. There is also a potential that there is no active market to trade floating rate obligations, that there may be restrictions on their transfer, or that the issuer may default. As a result, the Portfolio may be unable to sell floating rate obligations at the desired time or may be able to sell only at a price less than fair market value. In addition, if movements in interest rates are incorrectly anticipated, the Portfolio could lose money, or its net asset value could decline by the use of inverse floaters.

TBA Commitments Risk. Although TBA commitments must meet industry-accepted “good delivery” standards, there can be no assurance that a security purchased on a forward commitment basis will ultimately be issued or delivered by the counterparty. If the counterparty to a transaction fails to deliver the securities, the Portfolio could suffer a loss. Because TBA commitments do not require the delivery of a specific security, the characteristics of a security delivered to the Portfolio may be less favorable than expected. There is a risk that the security that the Portfolio buys will lose value between the purchase and settlement dates. TBA purchase and sales commitments may significantly increase the portfolio turnover rate and are not included in the portfolio turnover rate calculation.

Short Exposure Risk. The Portfolio may enter into a derivatives transaction to obtain short investment exposure to the underlying reference asset. If the value of the underlying reference asset on which the Portfolio has obtained a short investment exposure increases, the Portfolio will incur a loss. This potential loss is theoretically unlimited. A short exposure through a derivative also exposes the Portfolio to credit risk, counterparty risk, and leverage risk.

Rule 144A Securities and Other Exempt Securities Risk. Investments in securities issued under Regulation S and Rule 144A and other securities exempt from certain registration requirements could have the effect of decreasing the Portfolio’s liquidity profile or preventing the Portfolio from disposing of them promptly at advantageous prices. Investments in securities exempt from certain registration requirements may be less liquid than other investments because such securities may not always be readily sold in broad public markets and may have no active trading market. As a result, they may be difficult to value because market quotations may not be readily available.

ESG Integration Risk. There is a risk that considering ESG Factors as part of the Portfolio’s investment process may fail to produce the intended results or that the Portfolio may perform differently from funds that have a similar investment style but do not formally incorporate such considerations in their strategy. Information related to ESG Factors provided by issuers and third parties, which portfolio management may utilize, continues to develop and may be incomplete or inaccurate, use different methodologies, or be applied differently across issuers and industries.

Securities Lending Risk. There is the risk that when portfolio securities are lent, the securities may not be returned on a timely basis, and the Portfolio may experience delays and costs in recovering the security or gaining access to the collateral provided to the Portfolio to collateralize the loan. If the Portfolio is unable to recover a security on loan, the Portfolio may use the collateral to purchase replacement securities in the market. There is a risk that the value of the collateral could decrease below the cost of the replacement security by the time the replacement investment is made, resulting in a loss to the Portfolio.

An investment in the Portfolio is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

5 | Janus Henderson Balanced Portfolio

Performance information

The following information provides some indication of the risks of investing in the Portfolio by showing how the Portfolio’s performance has varied over time. The bar chart depicts the change in performance from year to year during the periods indicated. Total return figures include the effect of the Portfolio’s expenses, but do not include charges or expenses attributable to any insurance product, which would lower the performance illustrated. The table compares the average annual returns for the Service Shares of the Portfolio for the periods indicated to a broad-based securities market index, as well as to one or more additional indices that have investment characteristics similar to those of the Portfolio. All figures assume reinvestment of dividends and distributions.

The Portfolio’s past performance does not necessarily indicate how it will perform in the future. Updated performance information is available at janushenderson.com/VITperformance or by calling 1-877-335-2687.

Annual Total Returns for Service Shares (calendar year-end)

Best Quarter:

2nd Quarter 2020

12.85%

Worst Quarter:

2nd Quarter 2022

– 11.63%

Average Annual Total Returns (periods ended 12/31/24)
	1 Year	5 Years	10 Years
Balanced Portfolio
Service Shares	15.15%	8.06%	8.40%
S&P 500® Index (reflects no deduction for fees, expenses, or taxes)	25.02%	14.53%	13.10%
Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses, or taxes)	1.25%	– 0.33%	1.35%
Balanced Index (reflects no deduction for fees, expenses, or taxes)	14.45%	8.04%	7.99%

The Portfolio’s broad-based benchmark indices are the S&P 500 Index and the Bloomberg U.S. Aggregate Bond Index. The Portfolio’s additional benchmark index is the Balanced Index. The indices are described below.

•

The S&P 500 Index is a commonly recognized, market capitalization-weighted index of 500 widely held equity securities, designed to measure broad U.S. equity performance.

•

The Bloomberg U.S. Aggregate Bond Index is made up of U.S. dollar-denominated, fixed-rate taxable bonds, including securities that are of investment grade quality or better.

•

The Balanced Index is an internally-calculated, hypothetical combination of unmanaged indices. Prior to April 29, 2024, the Balanced Index reflects total returns of the S&P 500 Index (55%) and the Bloomberg U.S. Aggregate Bond Index (45%). Effective April 29, 2024, the Balanced Index reflects the total returns of the S&P 500 Index (60%) and the Bloomberg U.S. Aggregate Bond Index (40%).

Management

Investment Adviser: Janus Henderson Investors US LLC

6 | Janus Henderson Balanced Portfolio

Portfolio Management: Jeremiah Buckley, CFA, is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since December 2015. Michael Keough is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since December 2019. Greg Wilensky, CFA, is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since February 2020.

Purchase and sale of Portfolio shares

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Redemptions, like purchases, may be effected only through the separate accounts of participating insurance companies or through qualified retirement plans. Requests are duly processed at the net asset value next calculated after an order is received in good order by the Portfolio or its agents. Refer to the appropriate separate account prospectus or plan documents for details.

Tax information

Payments to Insurers, Broker-Dealers, and other financial intermediaries

Portfolio shares are generally available only through an insurer’s variable contracts, or through certain employer or other retirement plans (Retirement Products). Retirement Products are generally purchased through a broker-dealer or other financial intermediary. The Portfolio or its distributor (or its affiliates) may make payments to the insurer and/or its related companies for distribution and/or other services; some of the payments may go to broker-dealers and other financial intermediaries. These payments may create a conflict of interest for an intermediary, or be a factor in the insurer’s decision to include the Portfolio as an underlying investment option in a variable contract. Ask your financial advisor, visit your intermediary’s website, or consult your insurance contract prospectus for more information.

7 | Janus Henderson Balanced Portfolio

Additional information about the Portfolio

Fees and expenses

Please refer to the following important information when reviewing the “Fees and Expenses of the Portfolio” table in the Portfolio Summary of the Prospectus. The fees and expenses shown were determined based on average net assets as of the fiscal year ended December 31, 2024.

•

“Annual Fund Operating Expenses” are paid out of the Portfolio’s assets and include fees for portfolio management and administrative services, including recordkeeping, subaccounting, and other shareholder services. You do not pay these fees directly but, as the Example in the Portfolio Summary shows, these costs are borne indirectly by all shareholders.

•

The “Management Fee” is the investment advisory fee rate paid by the Portfolio to the Adviser. Refer to “Management Expenses” in this Prospectus for additional information with further description in the Statement of Additional Information (“SAI”).

•

“Distribution/Service (12b-1) Fees.” Because 12b-1 fees are charged as an ongoing fee, over time the fee will increase the cost of your investment and may cost you more than paying other types of sales charges.

•

“Other Expenses”

include an administrative services fee of 0.05% of the average daily net assets to compensate insurance companies or other financial intermediaries for services provided to contract owners and plan participants.

include acquired fund fees and expenses, which are indirect expenses the Portfolio may incur as a result of investing in shares of an underlying fund, to the extent such expenses are less than 0.01%. “Acquired Fund” refers to any underlying fund (including, but not limited to, exchange-traded funds) in which a portfolio invests or has invested during the period. To the extent that the Portfolio invests in Acquired Funds, the Portfolio’s “Total Annual Fund Operating Expenses” may not correlate to the “Ratio of gross expenses to average net assets” presented in the Financial Highlights table because that ratio includes only the direct operating expenses incurred by the Portfolio, not the indirect costs of investing in Acquired Funds. Such amounts are less than 0.01%.

may include reimbursement to Janus Henderson Services US LLC (the “Transfer Agent”), the Portfolio’s transfer agent, of its out-of-pocket costs for serving as transfer agent and providing servicing to shareholders, including servicing provided by third parties.

include custodian fees and expenses, legal and auditing fees, printing and mailing costs of sending reports and other information to existing shareholders, and Independent Trustees’ fees and expenses.

•

All expenses in the Portfolio’s “Fees and Expenses of the Portfolio” table are shown without the effect of expense offset arrangements. Pursuant to such arrangements, credits realized as a result of uninvested cash balances are used to reduce custodian and transfer agent expenses.

Additional investment strategies and general portfolio policies

The Portfolio’s Board of Trustees (“Trustees”) may change the Portfolio’s investment objective or non-fundamental principal investment strategies without a shareholder vote. The Portfolio will notify you in writing at least 60 days before making any such change it considers material. If there is a material change to the Portfolio’s investment objective or principal investment strategies, you should consider whether the Portfolio remains an appropriate investment for you. There is no guarantee that the Portfolio will achieve its investment objective.

Unless otherwise stated, the following section provides additional information about the investment strategies and general policies that are summarized in the Portfolio Summary section, including the types of securities the Portfolio may invest in when pursuing its investment objective. This section also describes investment strategies and policies that the Portfolio may use to a lesser extent. These non-principal investment strategies and policies may become more important in the future since the Portfolio’s composition can change over time. Except for the Portfolio’s policies with respect to illiquid investments, borrowing, and derivatives use, the percentage limitations included in these policies and elsewhere in this Prospectus and/or the SAI normally apply only at the time of purchase of a security. So, for example, if the Portfolio exceeds a limit, other than illiquid investments, borrowing, and derivatives use, as a result of market fluctuations or the sale of other securities, it will not be required to dispose of any securities. The “Glossary of Investment Terms” includes descriptions of investment terms used throughout the Prospectus.

8 | Janus Aspen Series

Security Selection

The Portfolio pursues its investment objective by normally investing 35-70% of its assets in equity securities and the remaining assets in fixed-income securities and cash equivalents. In choosing equity investments, portfolio management applies a “bottom-up” approach. In other words, equity portfolio management looks at companies one at a time to determine if a company is an attractive investment opportunity and if it is consistent with the Portfolio’s investment policies. Factors that equity portfolio management will consider in its fundamental analysis include a company’s revenue growth potential, returns on capital, and balance sheet flexibility. Equity portfolio management will generally consider selling a security when, among other things, it reaches or exceeds its targeted value, the investment thesis for owning the position has changed, or to rebalance industry or sector weightings. In choosing fixed-income investments, portfolio management’s investment process is research-driven, incorporating “top-down” and “bottom-up” factors to identify and manage exposure to risks across sectors, industries, and individual investments. Fixed-income portfolio management evaluates expected risk-adjusted returns on a portfolio and position level by analyzing fundamentals, valuations, and market technical indicators. This research encompasses both traditional fundamental analysis and data driven quantitative models and signals from such models.

Cash Position

The Portfolio may not always stay fully invested. For example, when portfolio management believes that market conditions are unfavorable for investing, or when it is otherwise unable to locate attractive investment opportunities, the Portfolio’s cash or similar investments may increase. When the Portfolio’s investments in cash or similar investments increase, it may not participate in market advances or declines to the same extent that it would if the Portfolio remained more fully invested. To the extent the Portfolio invests its uninvested cash through a sweep program (meaning its uninvested cash is pooled with uninvested cash of other funds and invested in certain securities such as repurchase agreements), it is subject to the risks of the account or fund into which it is investing, including liquidity issues that may delay the Portfolio from accessing its cash.

In addition, the Portfolio may temporarily increase its cash position under certain unusual circumstances, such as to protect its assets or maintain liquidity in certain circumstances to meet unusually large redemptions. The Portfolio’s cash position may also increase temporarily due to unusually large cash inflows. Under unusual circumstances such as these, the Portfolio may invest up to 100% of its assets in cash or similar investments. In this case, the Portfolio may take positions that are inconsistent with its investment policies. As a result, the Portfolio may not achieve its investment objective.

Derivatives

The Portfolio may invest in derivatives, which are financial instruments whose value is derived from, or directly linked to, an underlying asset, instrument, currency, or index. The Portfolio may take long and short positions in derivatives. Derivatives can be used for hedging purposes or for non-hedging purposes, such as seeking to earn income and enhance return, to protect unrealized gains, or to avoid realizing losses. Such techniques may also be used to adjust currency exposure relative to a benchmark index, to gain exposure to the market pending investment of cash balances, or to meet liquidity needs.

Emerging Markets

ESG Integration

As part of the Portfolio’s investment process, portfolio management considers environmental, social, and governance (“ESG”) risks and opportunities (“ESG Factors”) that it believes are financially material, alongside other fundamental investment factors. Examples of potential financially material ESG Factors may include corporate governance, political governance, executive pay, board structure and diversity, business ethics, corporate reporting, company culture, human capital management and diversity, community relations, human rights, exposure to climate change, biodiversity, and deforestation. Portfolio management focuses on the ESG Factors it considers most likely to have a material impact on the long-term financial performance of the issuer, which includes identifying ESG Factors attributable to a particular region, sector, industry, or issuer. To facilitate its assessment of ESG Factors, portfolio management uses issuer reports, third-party data and internally- generated analyses and may engage directly with issuers. ESG Factors are one of many considerations in the investment decision-making process, may not be determinative in deciding to include or exclude an investment from the portfolio, and may not be considered for every investment decision. Portfolio management may assess the relevance of ESG Factors to its fundamental research process differently across issuers, sectors, regions, and asset classes.

9 | Janus Aspen Series

Exchange-Traded Funds

The Portfolio may invest in exchange-traded funds (“ETFs”). ETFs are typically open-end investment companies that are traded on a national securities exchange. ETFs typically incur fees, such as investment advisory fees and other operating expenses that are separate from those of the Portfolio, which will be indirectly paid by the Portfolio. As a result, the cost of investing in the Portfolio may be higher than the cost of investing directly in ETFs and may be higher than other mutual funds that invest directly in stocks and bonds. Since ETFs are traded on an exchange at market prices that may vary from the net asset value of their underlying investments, there may be times when ETFs trade at a premium or discount.

Foreign Securities

The Portfolio may invest in foreign securities. Portfolio management seeks investments that meet the selection criteria, regardless of where an issuer or company is located. Foreign securities are generally selected on a security-by-security basis without regard to any predetermined allocation among countries or geographic regions. However, certain factors, such as expected levels of inflation, government policies influencing business conditions, the outlook for currency relationships, and prospects for economic growth among countries, regions, or geographic areas, may warrant greater consideration in selecting foreign securities. The Portfolio may at times have significant foreign exposure, including exposure to emerging markets.

High-Yield Bonds

Within the parameters of its specific investment policies, the Portfolio may invest in bonds that are rated below investment grade (also known as “junk” bonds), such as BB+ or lower by Standard & Poor’s Ratings Services (“Standard & Poor’s”) and Fitch, Inc. (“Fitch”), or Ba1 or lower by Moody’s Investors Service, Inc. (“Moody’s”) or is an unrated bond of similar quality. The Portfolio may also invest in unrated bonds of foreign and domestic issuers.

Illiquid Investments

The Portfolio will not acquire any illiquid investment if, immediately after the acquisition, the Portfolio would have invested more than 15% of its net assets in illiquid investments that are assets. An illiquid investment is any investment that the Portfolio reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment.

Inflation-Linked Securities

The Portfolio may invest in inflation-linked securities, including Treasury Inflation-Protected Securities (also known as TIPS), municipal inflation-indexed bonds and corporate inflation-indexed bonds, or in derivatives that are linked to these securities. TIPS are inflation-linked bonds issued by the U.S. Government. Inflation-linked bonds may also be issued by, or related to, sovereign governments of other developed countries, emerging market countries, or companies or other entities not affiliated with governments.

Inflation-linked bonds are fixed-income securities whose interest and principal payments are periodically adjusted according to the rate of inflation. The inflation adjustment, which is typically applied monthly to the principal of the bond, follows a designated inflation index, such as the consumer price index. If an index measuring inflation falls, the principal value of inflation-indexed bonds will typically be adjusted downward, and consequently the interest payable on these securities (calculated with respect to a smaller principal amount) will be reduced. Because of their inflation adjustment feature, inflation-linked bonds typically have lower yields than conventional fixed-rate bonds.

Inflation-linked bonds normally decline in price when real interest rates rise. In the event of deflation, when prices decline over time, the principal and income of inflation-linked bonds would likely decline, resulting in losses to the Portfolio.

In the case of TIPS, repayment of original bond principal upon maturity (as adjusted for inflation) is guaranteed. When TIPS mature, the holder is paid the adjusted principal or original principal, whichever is greater. For inflation-linked bonds that do not provide a similar guarantee, the adjusted principal value or maturity amount of the inflation-linked bond repaid at maturity may be less than the original principal.

Initial Public Offerings and Secondary Offerings

The Portfolio may purchase shares issued as part of, or a short period after, a company’s initial public offering (“IPO”), and may at times dispose of those shares shortly after their acquisition. An IPO is the first sale of stock by a private company to the public. IPOs are often issued by smaller, younger companies seeking the capital to expand, but can also be done by large privately-owned companies looking to become publicly traded. The Portfolio may also purchase shares in offerings made by companies that are publicly traded (“secondary offerings”). Secondary offerings may be made by companies for a number of

10 | Janus Aspen Series

reasons, including as part of a refinancing, to raise capital for growth, and/or to provide existing shareholders with a way to register and sell restricted shares.

Leverage

Certain of the Portfolio’s investments, including derivatives and short sale transactions, involve the use of leverage. Leverage is investment exposure which exceeds the initial amount invested. Leverage occurs when the Portfolio increases its assets available for investment using derivatives, short sales, when-issued, delayed delivery, or forward commitment transactions, or other similar transactions. The use of other investment techniques can also create a leveraging effect on the Portfolio.

Loans

The Portfolio may invest in various commercial loans, including bank loans, bridge loans, debtor-in-possession (“DIP”) loans, mezzanine loans, and other fixed and floating rate loans. These loans may be acquired through loan participations and assignments or on a when-issued basis.

Bank Loans. Bank loans are obligations of companies or other entities entered into in connection with recapitalizations, acquisitions, and refinancings. The Portfolio’s investments in bank loans are generally acquired as a participation interest in, or assignment of, loans originated by a lender or other financial institution. These investments may include institutionally-traded floating and fixed-rate debt securities.

Bridge Loans. Bridge loans are short-term loan arrangements typically made by a borrower in anticipation of receiving intermediate-term or long-term permanent financing. Most bridge loans are structured as floating-rate debt with step-up provisions under which the interest rate on the bridge loan increases the longer the loan remains outstanding. In addition, bridge loans commonly contain a conversion feature that allows the bridge loan investor to convert its loan interest to senior exchange notes if the loan has not been prepaid in full on or prior to its maturity date. Bridge loans typically are structured as senior loans, but may be structured as junior loans.

DIP Loans. DIP loans are issued in connection with restructuring and refinancing transactions. DIP loans are loans to a debtor-in-possession in a proceeding under the U.S. bankruptcy code that have been approved by the bankruptcy court. DIP loans are typically fully secured by a lien on the debtor’s otherwise unencumbered assets or secured by a junior lien on the debtor’s encumbered assets (so long as the loan is fully secured based on the most recent current valuation or appraisal report of the debtor). DIP loans are often required to close with certainty and in a rapid manner to satisfy existing creditors and to enable the issuer to emerge from bankruptcy or to avoid a bankruptcy proceeding.

Mezzanine Loans. Mezzanine loans are a hybrid of debt and equity financing that is typically used to fund the expansion of existing companies. A mezzanine loan is composed of debt capital that gives the lender the right to convert to an ownership or equity interest in the company if the loan is not paid back in time and in full. Mezzanine loans typically are the most subordinated debt obligation in an issuer’s capital structure.

Mortgage- and Asset-Backed Securities

The Portfolio may purchase fixed or variable rate commercial or residential mortgage-backed securities issued by the Government National Mortgage Association (“Ginnie Mae”), the Federal National Mortgage Association (“Fannie Mae”), the Federal Home Loan Mortgage Corporation (“Freddie Mac”), or other governmental or government-related entities. Ginnie Mae’s guarantees are backed by the full faith and credit of the U.S. Government, which means that the U.S. Government guarantees that the interest and principal will be paid when due. Fannie Mae and Freddie Mac securities, as well as the securities of other government or government-related entities, are not backed by the full faith and credit of the U.S. Government.

The Portfolio may also purchase mortgage- and asset-backed securities through single- and multi-seller conduits, collateralized loan obligations, structured investment vehicles, and other similar securities. Asset-backed securities may be backed by various consumer obligations, including automobile loans, equipment leases, credit card receivables, or other collateral. In the event the underlying loans are not paid, the securities’ issuer could be forced to sell the assets and recognize losses on such assets, which could impact the Portfolio’s return.

Portfolio Turnover

11 | Janus Aspen Series

reason of economic or other developments not foreseen at the time of the initial investment decision. The Portfolio may also sell one security and simultaneously purchase the same or a comparable security to take advantage of short-term differentials in bond yields or securities prices. Portfolio turnover is affected by market conditions, changes in the size of the Portfolio (including due to shareholder purchases and redemptions), the nature of the Portfolio’s investments, and the investment style of portfolio management. Changes are normally made in the Portfolio’s holdings whenever portfolio management believes such changes are desirable. Portfolio turnover rates are generally not a factor in making buy and sell decisions for the Portfolio.

Increased portfolio turnover may result in higher costs for brokerage commissions, dealer mark-ups, and other transaction costs. Higher costs associated with increased portfolio turnover also may have a negative effect on the Portfolio’s performance. The “Financial Highlights” section of this Prospectus shows the Portfolio’s historical turnover rates.

REITs and Real Estate-Related Securities

The Portfolio may invest in equity and debt securities of real estate-related companies. These securities may include common stocks, preferred stocks, and other securities, including, but not limited to, mortgage-backed securities, real estate-backed securities, securities of real estate investment trusts (“REITs”) and similar REIT-like entities (such as real estate operating companies (“REOCs”)). A REIT is an entity that invests in real estate-related projects, such as properties, mortgage loans, and construction loans. REITs are often categorized as equity REITs, mortgage REITs, and hybrid REITs. An equity REIT, the most common type of REIT, invests primarily in the fee ownership of land and buildings. An equity REIT derives its income primarily from rental income but may also realize capital gains or losses by selling real estate properties in its portfolio that have appreciated or depreciated in value. A mortgage REIT invests primarily in mortgages on real estate, which may secure construction, development, or long-term loans. A mortgage REIT generally derives its income from interest payments on the credit it has extended. A hybrid REIT combines the characteristics of equity REITs and mortgage REITs, generally by holding both ownership interests and mortgage interests in real estate.

Similar to REITs, REOCs are publicly-traded real estate companies that typically engage in the development, management or financing of real estate, such as homebuilders, hotel management companies, land developers and brokers. REOCs, however, have not elected (or are not eligible) to be taxed as a REIT. The reasons for not making such an election include the (i) availability of tax-loss carry-forwards, (ii) operation in non-REIT-qualifying lines of business, and (iii) ability to retain earnings. Instead, REOCs are generally structured as “C” corporations under the Internal Revenue Code of 1986, as amended, and, as a result, are not required to distribute any portion of their income. In this regard, although REOCs do not receive the same favorable tax treatment that is accorded to REITs, REOCs are typically subject to fewer restrictions than REITs, including the ability to retain and/or reinvest funds from operations and more flexibility in terms of the real estate investments they can make.

Securities Lending

The Portfolio may seek to earn additional income through lending its securities to certain qualified broker-dealers and institutions in an amount equal to up to one-third of its total assets as determined at the time of the loan origination. When the Portfolio lends its securities, it receives collateral (including cash collateral), at least equal to the value of securities loaned. The Portfolio may earn income by investing this collateral in one or more affiliated or non-affiliated cash management vehicles or in time deposits. It is also possible that, due to a decline in the value of a cash management vehicle in which collateral is invested, the Portfolio may lose money. There is also the risk that when portfolio securities are lent, the securities may not be returned on a timely basis, and the Portfolio may experience delays and costs in recovering the security or gaining access to the collateral provided to the Portfolio to collateralize the loan. If the Portfolio is unable to recover a security on loan, the Portfolio may use the collateral to purchase a replacement security in the market. There is a risk that the value of the collateral could be insufficient to cover the cost of the replacement security resulting in a loss to the Portfolio. In certain circumstances, individual loan transactions could yield negative returns. The Adviser intends to manage a portion of the cash collateral in an affiliated cash management vehicle and will receive an investment advisory fee for managing such assets.

Short Sales

12 | Janus Aspen Series

Portfolio has the right to obtain the amount of the security sold short at a specified date in the future. The Portfolio may also enter into a short sale to hedge against anticipated declines in the market price of a security or to reduce portfolio volatility.

A short sale is generally a transaction in which the Portfolio sells a security it does not own or have the right to acquire (or that it owns but does not wish to deliver) in anticipation that the market price of that security will decline. To complete the transaction, the Portfolio must borrow the security to make delivery to the buyer. The Portfolio is then obligated to replace the security borrowed by purchasing the security at the market price at the time of replacement. A short sale is subject to the risk that if the price of the security sold short increases in value, the Portfolio will incur a loss because it will have to replace the security sold short by purchasing it at a higher price. In addition, the Portfolio may not always be able to close out a short position at a particular time or at an acceptable price. A lender may request, or market conditions may dictate, that the borrowed securities be returned to the lender on short notice, and the Portfolio may have to buy the borrowed securities at an unfavorable price. If this occurs at a time when other short sellers of the same security also want to close out their positions, a “short squeeze” can occur, which means that the demand is greater than the supply for the security sold short. If a short squeeze occurs, it is more likely that the Portfolio will have to cover its short sale at an unfavorable price and potentially reduce or eliminate any gain, or cause a loss, as a result of the short sale. Because there is no upper limit to the price a borrowed security may reach prior to closing a short position, the Portfolio’s losses are potentially unlimited in a short sale transaction. The Portfolio’s gains and losses will also be decreased or increased, as the case may be, by the amount of any dividends, interest, or expenses, including transaction costs and borrowing fees, the Portfolio may be required to pay in connection with a short sale. Such payments may result in the Portfolio having higher expenses than a portfolio that does not engage in short sales and may negatively affect the Portfolio’s performance.

The Portfolio may enter into a derivatives transaction to obtain short investment exposure to an underlying reference asset. If the value of the underlying reference asset on which the Portfolio has obtained a short investment exposure increases, the Portfolio will incur a loss. This potential loss is theoretically unlimited. A short exposure through a derivative also exposes the Portfolio to credit risk, counterparty risk, and leverage risk.

Special Situations

The Portfolio may invest in companies that demonstrate special situations or turnarounds, meaning companies that have experienced significant business problems but are believed to have favorable prospects for recovery. For example, a special situation or turnaround may arise when, in the opinion of portfolio management, the securities of a particular issuer will be recognized as undervalued by the market and appreciate in value due to a specific development with respect to that issuer. Special situations may include significant changes in a company’s allocation of its existing capital, a restructuring of assets, or a redirection of free cash flow. For example, issuers undergoing significant capital changes may include companies involved in spin-offs, sales of divisions, mergers or acquisitions, companies involved in bankruptcy proceedings, or companies initiating large changes in their debt to equity ratio. Companies that are redirecting cash flows may be reducing debt, repurchasing shares, or paying dividends. Special situations may also result from: (i) significant changes in industry structure through regulatory developments or shifts in competition; (ii) a new or improved product, service, operation, or technological advance; (iii) changes in senior management or other extraordinary corporate event; (iv) differences in market supply of and demand for the security; or (v) significant changes in cost structure. Investments in “special situations” companies can present greater risks than investments in companies not experiencing special situations, and the Portfolio’s performance could be adversely impacted if the securities selected decline in value or fail to appreciate in value.

Swap Agreements

The Portfolio may utilize swap agreements including, but not limited to, credit default swaps, equity swaps, inflation index swaps, interest rate and currency swaps, total return swaps (including fixed-income total return swaps), and swaps on exchange-traded funds, as a means to gain exposure to certain companies or countries, and/or to “hedge” or protect its holdings from adverse movements in securities prices, the rate of inflation, or interest rates. Swaps may also be used for capital appreciation. Swap agreements are two-party contracts to exchange one set of cash flows for another. Swap agreements entail the risk that a party will default on its payment obligations to the Portfolio. If the other party to a swap defaults, the Portfolio would risk the loss of the net amount of the payments that it contractually is entitled to receive. If the Portfolio utilizes a swap at the wrong time or judges market conditions incorrectly, the swap may result in a loss to the Portfolio and reduce the Portfolio’s total return. Various types of swaps such as credit default, equity, interest rate, currency, inflation index, and total return are described in the “Glossary of Investment Terms.”

13 | Janus Aspen Series

credit default swaps or a commercial mortgage-backed index) in a more efficient manner than transacting in a single-name credit default swap. If a credit event occurs in one of the underlying companies, the protection is paid out via the delivery of the defaulted bond by the buyer of protection in return for a payment of notional value of the defaulted bond by the seller of protection or it may be settled through a cash settlement between the two parties. The underlying company is then removed from the index. New series of CDX are issued on a regular basis.

TBA Commitments

The Portfolio may enter into “to be announced” or “TBA” commitments. TBA commitments are forward agreements for the purchase or sale of securities, including mortgage-backed securities, for a fixed price, with payment and delivery on an agreed upon future settlement date. The specific securities to be delivered are not identified at the trade date. However, delivered securities must meet specified terms, including issuer, rate, and mortgage terms. At the time the TBA commitment is made, the transaction is recorded and thereafter the value of such securities is reflected each day in determining the Portfolio’s net asset value. Because the Portfolio is generally not required to pay for the security until the settlement date, if the Portfolio remains substantially fully invested at a time when TBA commitment purchases are outstanding, the purchases may result in a form of leverage.

U.S. Government Securities

The Portfolio may invest in U.S. Government securities. U.S. Government securities include those issued directly by the U.S. Treasury and those issued or guaranteed by various U.S. Government agencies and instrumentalities. Some government securities are backed by the full faith and credit of the United States. Other government securities are backed only by the rights of the issuer to borrow from the U.S. Treasury. Others are supported by the discretionary authority of the U.S. Government to purchase the obligations. Certain other government securities are supported only by the credit of the issuer. For securities not backed by the full faith and credit of the United States, the Portfolio must look principally to the agency or instrumentality issuing or guaranteeing the securities for repayment and may not be able to assert a claim against the United States if the agency or instrumentality does not meet its commitment. Such securities may involve increased risk of loss of principal and interest compared to government debt securities that are backed by the full faith and credit of the United States.

Because of the rising U.S. Government debt burden, it is possible that the U.S. Government may not be able to meet its financial obligations or that securities issued or backed by the U.S. Government may experience credit downgrades. Such a credit event may adversely affect the financial markets.

Other Types of Investments

Unless otherwise stated within its specific investment policies, the Portfolio may also invest in other types of domestic and foreign securities and use other investment strategies. These securities and strategies are not intended to be principal investment strategies of the Portfolio. If successful, they may benefit the Portfolio by earning a return on the Portfolio’s assets or reducing risk; however, they may not achieve the Portfolio’s investment objective. These securities and strategies may include:

•

indexed/structured securities (such as commercial and residential mortgage- and asset-backed securities)

•

securities purchased on a when-issued, delayed delivery, or forward commitment basis

•

equity and fixed-income securities issued in private placement transactions

Risks of the Portfolio

The value of your investment will vary over time, sometimes significantly, and you may lose money by investing in the Portfolio. To varying degrees, the Portfolio may invest in equity securities, fixed-income securities, money market instruments or cash/cash equivalents, and derivatives. The following information is intended to help you better understand some of the risks of investing in the Portfolio, including those risks that are summarized in the Portfolio Summary section. This information also includes descriptions of other risks the Portfolio may be subject to as a result of additional investment strategies and general policies that may apply to the Portfolio. The impact of the following risks on the Portfolio may vary depending on the Portfolio’s investments. The greater the Portfolio’s investment in a particular security, the greater the Portfolio’s exposure to the risks associated with that security. Before investing in the Portfolio, you should consider carefully the risks that you assume when investing in the Portfolio.

14 | Janus Aspen Series

Counterparty Risk. Portfolio transactions involving a counterparty are subject to the risk that the counterparty or a third party will not fulfill its obligation to the Portfolio (“counterparty risk”). Counterparty risk may arise because of the counterparty’s financial condition (i.e., financial difficulties, bankruptcy, or insolvency), market activities and developments, or other reasons, whether foreseen or not. A counterparty’s inability to fulfill its obligation may result in significant financial loss to the Portfolio. The Portfolio may be unable to recover its investment from the counterparty or may obtain a limited recovery, and/or recovery may be delayed. The Portfolio may be exposed to counterparty risk to the extent it participates in lending its securities to third parties and/or cash sweep arrangements whereby the Portfolio’s cash balance is invested in one or more types of cash management vehicles or in time deposits. In addition, the Portfolio may be exposed to counterparty risk through its investments in certain securities, including, but not limited to, repurchase agreements, debt securities, and derivatives (including various types of swaps, futures, and options). The Portfolio intends to enter into financial transactions with counterparties that the Adviser believes to be creditworthy at the time of the transaction. There is always the risk that the Adviser’s analysis of a counterparty’s creditworthiness is incorrect or may change due to market conditions. To the extent that the Portfolio focuses its transactions with a limited number of counterparties, it will have greater exposure to the risks associated with one or more counterparties.

Credit Quality Risk. Through the Portfolio’s investments in fixed-income securities, the Portfolio is subject to the risks associated with the credit quality of the issuers of those fixed-income securities. Credit quality measures the likelihood that the issuer or borrower will meet its obligations on a security. One of the fundamental risks is credit risk, which is the risk that an issuer will be unable to make principal and interest payments when due, or default on its obligations. Higher credit risk may negatively impact the Portfolio’s returns.

Many fixed-income securities receive credit ratings from services such as Standard & Poor’s, Fitch, and Moody’s. These services assign ratings to securities by assessing the likelihood of issuer default. The lower a bond issue is rated by an agency, the more credit risk it is considered to represent. Lower rated instruments and securities generally pay interest at a higher rate to compensate for the associated greater risk. Interest rates can fluctuate in response to economic or market conditions, which can result in a fluctuation in the price of a security and impact the Portfolio’s return. If a security has not received a rating, the Portfolio must rely upon the Adviser’s credit assessment, which if incorrect can also impact the Portfolio’s returns. Please refer to the “Explanation of Rating Categories” section of the SAI for a description of bond rating categories.

Credit Risk Transfer Securities Risk. Credit risk transfer securities (“CRTs”) are unguaranteed and unsecured fixed or floating rate general obligations that are commonly issued by government sponsored enterprises. CRTs are not directly linked to or backed by the underlying mortgage loans, so investors such as the Portfolio have no direct recourse to the underlying mortgage loans in the event of a default. The risks associated with CRTs are different from the risks associated with investments in mortgage-backed securities issued by government sponsored enterprises or private issuers because some or all of the mortgage default or credit risk associated with the underlying mortgage loans is transferred to investors. These risks are in addition to the risks described under “Fixed-Income Securities Risk.”

The Portfolio may use short sales, futures, options, swap agreements (including, but not limited to, equity, interest rate, credit default, and total return), and other derivative instruments individually or in combination to “hedge” or protect its portfolio from adverse movements in securities prices and interest rates. The Portfolio may also use a variety of currency hedging techniques, including the use of forward currency contracts, to manage currency risk. There is no guarantee that portfolio management’s use of derivative investments will benefit the Portfolio. The Portfolio’s performance could be worse than if the Portfolio had not used such instruments. Use of such investments may instead increase risk to the Portfolio, rather than reduce risk.

Derivatives can be complex instruments and may involve analysis that differs from that required for other investment types used by the Portfolio. If the value of a derivative does not correlate well with the particular market or other asset class to which the derivative is intended to provide exposure, the derivative may not produce the anticipated result. Derivatives can also reduce the opportunity for gain or result in losses by offsetting positive returns in other investments.

•

15 | Janus Aspen Series

futures or swaps markets, or an imperfect correlation between the underlying instrument and the interest rate portfolio management is seeking to hedge, a correct forecast of general interest rate trends by portfolio management may not result in the successful use of futures and swaps related to interest rates.

•

Index Credit Default Swaps Risk. If the Portfolio holds a long position in CDX, the Portfolio would indirectly bear its proportionate share of any expenses paid by CDX. By investing in CDX, the Portfolio could be exposed to illiquidity risk, counterparty risk, and credit risk of the issuers of the underlying loan obligations and of the CDX markets. If there is a default by the CDX counterparty, the Portfolio will have contractual remedies pursuant to the agreements related to the transaction. CDX also bear the risk that the Portfolio will not be able to meet its obligation to the counterparty.

Emerging Markets Risk. Within the parameters of its specific investment policies, the Portfolio may invest in securities of issuers or companies from or with exposure to one or more “developing countries” or “emerging market countries.” Such countries include, but are not limited to, countries included in the MSCI Emerging Markets Index. To the extent that the Portfolio invests a significant amount of its assets in one or more of these countries, its returns and net asset value may be affected to a large degree by events and economic conditions in such countries. The risks of foreign investing are heightened when investing in emerging markets, which may result in the price of investments in emerging markets experiencing sudden and sharp price swings. In many developing markets, there is less government supervision and regulation of stock exchanges, brokers, and listed companies than in more developed markets, making these investments potentially more volatile in price and less liquid than investments in developed securities markets, resulting in greater risk to investors. There is a risk in developing countries that a current or future economic or political crisis could lead to price controls, forced mergers of companies, expropriation or confiscatory taxation, imposition or enforcement of foreign ownership limits, seizure, nationalization, sanctions or imposition of restrictions by various governmental entities on investment and trading, or creation of government monopolies, any of which may have a detrimental effect on the Portfolio’s investments.

The securities markets of many of these emerging market countries may also be smaller, less liquid, and subject to greater price volatility than those in the United States. In the event of a default on any investments in foreign debt obligations, it may be more difficult for the Portfolio to obtain or to enforce a judgment against the issuers of such securities. In addition, the Portfolio’s investments may be denominated in foreign currencies and therefore, changes in the value of a country’s currency compared to the U.S. dollar may affect the value of the Portfolio’s investments. To the extent that the Portfolio invests a significant portion of its assets in the securities of emerging markets issuers in or companies of a single country or region, it is more likely to be impacted by events or conditions affecting that country or region, which could have a negative impact on the Portfolio’s performance. The Portfolio may be subject to emerging markets risk to the extent that it invests in securities of issuers or companies which are not considered to be from emerging markets, but which have customers, products, or transactions associated with emerging markets.

ESG Integration Risk. There is a risk that considering ESG Factors as part of the Portfolio’s investment process, may fail to produce the intended results or that the Portfolio may perform differently from portfolios that have a similar investment style but do not formally incorporate such considerations in their strategy. While portfolio management believes that the consideration of financially material ESG Factors has the potential to provide better risk-adjusted returns, ESG Factors may not be considered for every investment decision and there is no guarantee that the consideration of ESG Factors will result in better performance. In addition, information related to ESG Factors provided by issuers and third parties, which portfolio management may utilize, continues to develop, and may be incomplete, inaccurate, use different methodologies or be applied differently across issuers and industries. Further, the U.S. regulatory landscape regarding the use of ESG Factors in investing is still developing and future rules and regulations may require the Portfolio to modify or alter its investment process and/or how it discloses its consideration of ESG Factors.

Exchange-Traded Funds Risk. ETFs are traded on a national securities exchange at market prices that may vary from the net asset value of their underlying investments. Accordingly, there may be times when an ETF trades at a premium or discount to its net asset value. When the Portfolio invests in an ETF, in addition to directly bearing the expenses associated with its own operations, it will bear a pro rata portion of the ETF’s expenses. As a result, the cost of investing in the Portfolio may be higher than the cost of investing directly in ETFs and may be higher than other mutual funds that invest directly in stocks and bonds. ETFs also involve the risk that an active trading market for an ETF’s shares may not develop or be maintained. Similarly, because the value of ETF shares depends on the demand in the market, the Portfolio may not be able to purchase or sell an ETF at the most optimal time, which could adversely affect the Portfolio’s performance. In addition, ETFs that track

16 | Janus Aspen Series

particular indices may be unable to match the performance of such underlying indices due to the temporary unavailability of certain index securities in the secondary market or other factors, such as discrepancies with respect to the weighting of securities.

The ETFs in which the Portfolio may invest are subject to specific risks, depending on the investment strategy of the ETF. In turn, the Portfolio will be subject to substantially the same risks as those associated with direct exposure to the securities or commodities held by the ETF. Because the Portfolio may invest in a broad range of ETFs, such risks may include, but are not limited to, leverage risk, foreign exposure risk, and commodity-linked investments risk. To the extent the Portfolio invests in fixed-income ETFs, it will be indirectly exposed to the same risks described under “Fixed-Income Securities Risk.”

Fixed-Income Securities Risk. The Portfolio holds debt and other fixed-income securities to generate income. Typically, the values of fixed-income securities change inversely with prevailing interest rates. Therefore, a fundamental risk of fixed-income securities is interest rate risk, which is the risk that the value of such securities will generally decline as prevailing interest rates rise, which may cause the Portfolio’s net asset value to likewise decrease. How specific fixed-income securities may react to changes in interest rates will depend on the specific characteristics of each security. For example, while securities with longer maturities and durations tend to produce higher yields, they also tend to be more sensitive to changes in prevailing interest rates and are therefore more volatile than shorter-term securities and are subject to greater market fluctuations as a result of changes in interest rates. However, calculations of maturity and duration may be based on estimates and may not reliably predict a security’s price sensitivity to changes in interest rates. In addition, different interest rate measures (such as short- and long-term interest rates and U.S. and non-U.S. interest rates), or interest rates on different types of securities or securities of different issuers, may not necessarily change in the same amount or in the same direction. Investments in fixed-income securities with very low or negative interest rates may diminish the Portfolio’s yield and performance.

Fixed-income securities are also subject to credit risk, which is the risk that the credit strength of an issuer of a fixed-income security will weaken and/or that the issuer will be unable to make timely principal and interest payments and that the security may go into default. In addition, there is prepayment risk, which is the risk that during periods of falling interest rates, certain debt obligations may be paid off quicker than originally anticipated, which may cause the Portfolio to reinvest its assets in securities with lower yields, resulting in a decline in the Portfolio’s income or return potential. Fixed-income securities may also be subject to extension risk, valuation risk and liquidity risk. Extension risk is the risk that during periods of rising interest rates, certain debt obligations may be paid off substantially slower than originally anticipated, and as a result, the value of those obligations may fall. Valuation risk is the risk that one or more of the fixed-income securities in which the Portfolio invests are priced differently than the value realized upon such security’s sale. In times of market instability, valuation may be more difficult. Valuation may also be affected by changes in the issuer’s financial strength, the market’s perception of such strength, or in the credit rating of the issuer of the security. Liquidity risk is the risk that fixed-income securities may be difficult or impossible to sell at the time portfolio management would like or at the price portfolio management believes the security is currently worth. Consequently, the Portfolio may have to accept a lower price to sell a security, sell other securities to raise cash, or give up an investment opportunity, any of which could have a negative effect on the Portfolio’s performance. In unusual market conditions, even normally liquid securities may be affected by a degree of liquidity risk. To the extent the Portfolio invests in fixed-income securities in a particular industry or economic sector, its share values may fluctuate in response to events affecting that industry or sector. Securities underlying mortgage- and asset-backed securities, which may include subprime mortgages, also may be subject to a higher degree of credit risk, valuation risk, and liquidity risk. To the extent that the Portfolio invests in derivatives tied to fixed-income securities, the Portfolio may be more substantially exposed to these risks than a portfolio that does not invest in such derivatives. The market for certain fixed-income securities may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Similarly, the amount of assets deemed illiquid remaining within the Portfolio may also increase, making it more difficult to meet shareholder redemptions and further adversely affecting the value of the Portfolio.

Foreign Exposure Risk. Within the parameters of its specific investment policies, the Portfolio may invest in foreign debt and equity securities either indirectly (e.g., depositary receipts, depositary shares, and passive foreign investment companies) or directly in foreign markets, including emerging markets. Additional risks may be present with respect to investments in securities of issuers or companies that are economically tied to different countries throughout the world. An issuer is deemed to be economically tied to a country or countries if one or more of the following tests are met: (i) the issuer is organized in, or its primary business office or principal trading market of its equity is located in, the country; (ii) a majority of the issuer’s revenues are derived from one or more countries; or (iii) a majority of the issuer’s assets are located in one or more countries.

17 | Janus Aspen Series

Investments in foreign securities, including securities of foreign and emerging market governments, may involve greater risks than investing in domestic securities because the Portfolio’s performance may depend on factors other than the performance of a particular company. These factors include:

•

Currency Risk. As long as the Portfolio holds a foreign security, its value will be affected by the value of the local currency relative to the U.S. dollar. When the Portfolio sells a foreign currency denominated security, its value may be worth less in U.S. dollars even if the security increases in value in its home country. U.S. dollar-denominated securities of foreign issuers may also be affected by currency risk, as the value of these securities may also be affected by changes in the issuer’s local currency.

•

Foreign Market Risk. Foreign securities markets, particularly those of emerging market countries, may be less liquid and more volatile than domestic markets. These securities markets may trade a small number of securities, may have a limited number of issuers and a high proportion of shares, or may be held by a relatively small number of persons or institutions. Local securities markets may be unable to respond effectively to increases in trading volume, potentially making prompt liquidation of substantial holdings difficult or impossible at times. It is also possible that certain markets may require payment for securities before delivery, and delays may be encountered in settling securities transactions. In some foreign markets, there may not be protection against failure by other parties to complete transactions. It may not be possible for the Portfolio to repatriate capital, dividends, interest, and other income from a particular country or governmental entity. In addition, securities of issuers located in or economically tied to countries with emerging markets may have limited marketability and may be subject to more abrupt or erratic price movements which could also have a negative effect on the Portfolio. Such factors may hinder the Portfolio’s ability to buy and sell emerging market securities in a timely manner, affecting the Portfolio’s investment strategies and potentially affecting the value of the Portfolio.

•

Political and Economic Risk. Foreign investments may be subject to increased political and economic risks, including the imposition of economic and other sanctions. Sanctions imposed by the U.S. Government on other countries or persons or issuers operating in such countries could restrict the Portfolio’s ability to buy affected securities or force the Portfolio to dispose of any affected securities it has previously purchased at an inopportune time. As a result, the Portfolio may experience a greater risk of loss with respect to securities impacted by such sanctions.

Political and economic risks may be heightened in emerging markets, which may have relatively unstable governments, immature economic structures, national policies restricting investments by foreigners, social instability, and different and/or developing legal systems. In some countries, there is the risk that the government may take over the assets or operations of a company or that the government may impose withholding and other taxes or limits on the removal of the Portfolio’s assets from that country. In addition, the economies of emerging markets may be predominantly based on only a few industries, may be highly vulnerable to changes in local or global trade conditions, and may suffer from extreme and volatile debt burdens or inflation rates.

•

Regulatory Risk. There may be less government supervision of foreign markets. As a result, foreign issuers may not be subject to the uniform accounting, auditing, and financial reporting standards and practices applicable to domestic issuers, and there may be less publicly available information about foreign issuers.

•

Transaction Costs Risk. Costs of buying, selling, and holding foreign securities, including brokerage, tax, and custody costs, may be higher than those involved in domestic transactions.

Geographic Concentration Risk. To the extent that the Portfolio invests a substantial amount of its assets in issuers located in a single country or region, the economic, political, social, regulatory, or other developments or conditions within such country or region will generally have a greater effect on the Portfolio than they would on a more geographically diversified portfolio, which may result in greater losses and volatility. Adverse developments in certain regions could also adversely affect securities of other countries whose economies appear to be unrelated and could have a negative impact on the Portfolio’s performance.

High-Yield Bond Risk. High-yield bonds (also known as “junk” bonds) are bonds rated below investment grade by the primary rating agencies such as Standard & Poor’s, Fitch, and Moody’s or are unrated bonds of similar quality. The value of lower quality bonds generally is more dependent on credit risk than investment grade bonds. Issuers of high-yield bonds may not be as strong financially as those issuing bonds with higher credit ratings and are more vulnerable to real or perceived economic changes, political changes, or adverse developments specific to the issuer. In addition, the junk bond market can experience sudden and sharp price swings.

18 | Janus Aspen Series

The secondary market on which high-yield securities are traded is less liquid than the market for investment grade securities. The lack of a liquid secondary market may have an adverse impact on the market price of the security. Additionally, it may be more difficult to value the securities because valuation may require more research, and elements of judgment may play a larger role in the valuation because there is less reliable, objective data available.

Please refer to the “Explanation of Rating Categories” section of the SAI for a description of bond rating categories.

Industry and Sector Risk. Industry and sector risk is the possibility that a group of related securities will decline in price due to industry-specific or economic sector-specific developments. Companies in the same or similar industries and economic sectors may share common characteristics and are more likely to react similarly to industry-specific market or economic developments. The Portfolio’s investments, if any, in multiple companies in a particular industry or economic sector may increase the Portfolio’s exposure to industry and sector risk.

Inflation Risk. Inflation risk is the risk that the value of certain assets or real income from investments will be worth less in the future as inflation decreases the value of money. As inflation increases, the present value of the Portfolio’s assets and distributions may decline. This risk may be elevated in a low interest rate environment.

Inflation-Linked Investments Risk. Inflation-linked bonds (including TIPS), and other inflation-linked securities normally will decline in price when real interest rates rise. In certain interest rate environments, such as when real interest rates are rising faster than nominal interest rates, inflation-linked bonds may experience greater losses than other fixed-income securities with similar durations. Except for the Portfolio’s investments in TIPS, which are guaranteed as to principal by the U.S. Treasury, the inflation-adjusted principal value or maturity amount of inflation-linked bonds repaid at maturity may be less than the original principal. Because of their inflation-linked adjustment feature, inflation-linked bonds typically have lower yields than conventional fixed-rate securities. In the event of deflation, where prices decline over time, the principal and income of inflation-linked bonds will likely decline, resulting in losses to the Portfolio.

Initial Public Offering and Secondary Offering Risk. The Portfolio’s purchase of shares issued in an IPO exposes it to the risks associated with companies that have little operating history as public companies, as well as to the risks inherent in those sectors of the market where these new issuers operate. Attractive IPOs are often oversubscribed and may not be available to the Portfolio, or may be available only in very limited quantities. The market for IPO issuers has been volatile, and share prices of newly public companies have fluctuated up and down significantly over short periods of time. There can be no assurance that the Portfolio will identify favorable IPO investment opportunities. In addition, under certain market conditions, a relatively small number of companies may issue securities in IPOs. Similarly, as the number of portfolios to which IPO securities are allocated increases, the number of securities issued to any one portfolio may decrease. In addition, as the portfolio increases in size, the impact of IPOs on the portfolio’s performance will generally decrease.

The Portfolio may purchase shares in secondary offerings. Secondary offerings may expose the Portfolio to some of the risks of IPOs. Participation in secondary offerings may have a magnified impact on the performance of a portfolio to the extent that it has a small asset base and the portfolio may not experience similar performance as its assets grow. Secondary offering shares frequently are volatile in price. As a result, the Portfolio may hold secondary offering shares for a very short period of time. This may increase the portfolio turnover rate of the Portfolio and may lead to increased expenses for the Portfolio, such as commissions and transaction costs. In addition, secondary offering shares can experience an immediate drop in value if the demand for the securities does not continue to support the offering price.

Interest Rate Risk. Generally, a fixed-income security will increase in value when prevailing interest rates fall and decrease in value when prevailing interest rates rise. Longer-term securities are generally more sensitive to interest rate changes than shorter-term securities, but they generally offer higher yields to compensate investors for the associated risks. High-yield bond prices and floating rate debt security prices are generally less directly responsive to interest rate changes than investment grade issues or comparable fixed rate securities, and may not always follow this pattern.

Leverage Risk. Some transactions may give rise to a form of economic leverage. These transactions may include, among others, derivatives, and may expose the Portfolio to greater risk and increase its costs. The use of leverage may cause the Portfolio to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet the applicable requirements of the Investment Company Act of 1940, as amended, and the rules thereunder. Increases and decreases in the value of the Portfolio’s holdings will be magnified when the Portfolio uses leverage.

19 | Janus Aspen Series

liquid in response to market developments or adverse investor perceptions. Investments that are illiquid or that trade in lower volumes may be more difficult to value. When there is no willing buyer and investments cannot be readily sold at the desired time or price, the Portfolio may have to accept a lower price or may not be able to sell the security or instrument at all. Investments in foreign securities, particularly those of issuers located in emerging market countries, tend to have greater exposure to liquidity risk than domestic securities. In unusual market conditions, even normally liquid securities may be affected by a degree of liquidity risk (i.e., if the number and capacity of traditional market participants is reduced). An inability to sell one or more portfolio positions can adversely affect the Portfolio’s value or prevent the Portfolio from being able to take advantage of other investment opportunities. Liquidity risk may be increased to the extent that the Portfolio invests in Rule 144A and other securities exempt from certain registration requirements that are deemed to be illiquid investments.

Liquidity risk may also refer to the risk that the Portfolio will not be able to pay redemption proceeds within the allowable time period because of unusual market conditions, an unusually high volume of redemption requests, or other reasons. While the Portfolio may pay redemptions in-kind, the Portfolio may instead choose to raise cash to meet redemption requests through the sale of portfolio securities or permissible borrowings. If the Portfolio is forced to sell securities at an unfavorable time and/or under unfavorable conditions, such sales may adversely affect the Portfolio’s net asset value and may increase brokerage costs.

Loan Risk. The Portfolio may invest in various commercial loans. The risks of such investments vary, depending on the type of loans underlying the investments, as described below.

•

Bank Loan Risk. The bank loans in which the Portfolio invests may be denominated in U.S. or non-U.S. currencies, including the euro. Bank loans are obligations of companies or other entities entered into in connection with recapitalizations, acquisitions, and refinancings. The Portfolio’s investments in bank loans are generally acquired as a participation interest in, or assignment of, loans originated by a lender or other financial institution. These investments may include institutionally-traded floating and fixed-rate debt securities. The bank loans underlying these securities often involve borrowers with low credit ratings whose financial conditions are troubled or uncertain, including companies that are highly leveraged or in bankruptcy proceedings. Participation interests and assignments involve credit, interest rate, and liquidity risk. Some participation interests and assignments may not be considered “securities,” and purchasers, such as the Portfolio, therefore may not be entitled to rely on the anti-fraud protections of the federal securities laws. Additionally, because the Adviser, in the course of investing the Portfolio’s assets in loans, may have access to material non-public information regarding the borrower, the ability of the Portfolio to purchase or sell publicly-traded securities of such borrowers may be restricted. In addition, to the extent the Portfolio invests in non-U.S. bank loan investments, those investments also are subject to the risks of foreign investment.

If the Portfolio purchases a participation interest, it may only be able to enforce its rights through the lender and may assume the credit risk of both the borrower and the lender. There are also risks involved in purchasing assignments. If a loan is foreclosed, the Portfolio may become part owner of any collateral securing the loan and may bear the costs and liabilities associated with owning and disposing of any collateral. The Portfolio could be held liable as a co-lender. In addition, there is no assurance that the liquidation of any collateral from a secured loan would satisfy a borrower’s obligations or that any collateral could be liquidated. There may be a number of intermediate participants in bank loan transactions and loan agreements that have specific rights, obligations, terms, and conditions. As such, any number of factors in an investment in bank loans could cause the Portfolio to lose income or principal on a particular investment, which in turn could affect the Portfolio’s returns, and you could lose money.

Interest rates on floating rate bank loans adjust with interest rate changes and/or issuer credit quality, and unexpected changes in such rates could result in losses to the Portfolio. Additionally, borrowers may pay back principal in whole or part, prior to scheduled due dates. Such prepayment may result in the Portfolio realizing less income on a particular investment and replacing the floating rate bank loan with a less attractive security, which may provide less return to the Portfolio.

Bank loans are generally less liquid than many other fixed-income securities and may be subject to restrictions on resale. Transactions in bank loans may take more than seven days to settle. As a result, the proceeds related to the sale of bank loans may not be available to make additional investments or to meet the Portfolio’s redemption obligations until a substantial period after the sale of the loans. To the extent that extended settlement creates short-term liquidity needs, the

20 | Janus Aspen Series

Portfolio may satisfy these needs by holding additional cash or selling other investments (potentially at an inopportune time, which could result in losses to the Portfolio).

The Portfolio may not be able to identify and invest in attractive floating rate bank loans, such as senior loans, as the market for such investments may be limited in certain economic conditions or because of a high number of potential purchasers of assignments and participations. The Portfolio may also invest in other floating rate debt securities or other investments. For example, the Portfolio may invest in junior or subordinated loans or unsecured loans. Such loans may not provide desired returns or may increase the potential for loss of income or principal. Bank loan investments may be generally considered speculative and risks arising from the Portfolio’s investments in bank loans may be similar to those of investments in “junk” bonds or below investment grade investments. The Portfolio’s investments in bank loans may be more sensitive to economic changes, political changes, or adverse developments specific to the borrower than higher quality investments.

•

Bridge Loan Risk. Investments in bridge loans subject the Portfolio to certain risks in addition to those described above. In addition, any delay in obtaining permanent financing subjects the bridge loan investor to increased risk. A borrower’s use of bridge loans also involves the risk that the borrower may be unable to locate permanent financing to replace the bridge loan, which may impair the borrower’s perceived creditworthiness.

•

DIP Loan Risk. Investments in DIP loans are subject to the risk that the entity will not emerge from bankruptcy and will be forced to liquidate its assets. In the event of liquidation, the Portfolio’s only recourse will be against the property securing the DIP loan.

•

Mezzanine Loan Risk. Mezzanine loans generally are rated below investment grade, and frequently are unrated. Because mezzanine loans typically are the most subordinated debt obligation in an issuer’s capital structure, they are subject to the additional risk that the cash flow of the related borrower and any property securing the loan may be insufficient to repay the loan after the related borrower pays off any senior obligations. Mezzanine loans, which are usually issued in private placement transactions, may be considered illiquid. In addition, they are often used by smaller companies that may be highly leveraged, and in turn may be subject to a higher risk of default. Investment in mezzanine loans is a specialized practice that depends more heavily on independent credit analysis than investments in other fixed-income securities.

Market Risk. The value of the Portfolio’s holdings may decrease if the value of one or more issuers in the Portfolio decreases. Further, regardless of how well individual companies or securities perform, the value of the Portfolio’s holdings could also decrease if there are deteriorating economic or market conditions, including, but not limited to, a general decline in prices on the stock markets, a general decline in real estate markets, a decline in commodities prices, or if the market favors different types of securities than the types of securities in which the Portfolio invests. If the value of the Portfolio’s holdings decreases, the Portfolio’s net asset value will also decrease, which means if you sell your shares in the Portfolio you may lose money. Market risk may affect a single issuer, industry, economic sector, or the market as a whole.

The increasing interconnectivity between global economies and financial markets increases the likelihood that events or conditions in one region or financial market may adversely impact issuers in a different country, region or financial market. Social, political, economic and other conditions and events, such as natural disasters, health emergencies (e.g., epidemics and pandemics), terrorism, war, armed conflicts, including related sanctions, social unrest, tariffs, trade disputes, financial institution failures, and economic recessions could reduce consumer demand or economic output, result in market closures, travel restrictions and/or quarantines, and generally have a significant and negative impact on the global economies and financial markets.

•

Armed Conflicts Risk. Examples include conflict, loss of life, and disaster connected to ongoing armed conflict between Russia and Ukraine in Europe and Hamas and Israel in the Middle East. The extent and duration of each conflict, resulting sanctions, and resulting future market disruptions in each region are impossible to predict, but could be significant and have a severe adverse effect, including significant negative impacts on the United States and broader global economy and the markets for certain securities and commodities.

21 | Janus Aspen Series

extent the Portfolio transacts in instruments such as derivatives, the Portfolio may hold investments, which may be significant, in money market fund shares to cover its obligations resulting from the Portfolio’s investments in derivatives. An investment in a money market fund is not a bank deposit and is not insured or guaranteed by any bank, the Federal Deposit Insurance Corporation or any other government agency. There can be no assurance that a money market fund will maintain a $1.00 per share net asset value at all times. Factors that could adversely affect the value of a money market fund’s shares include, among other things, a sharp rise in interest rates, an illiquid market for the securities held by the money market fund, a high volume of redemption activity in a fund’s shares, and a credit event or credit rating downgrade affecting one or more of the issuers of securities held by the money market fund. In addition, the failure of even an unrelated money market fund to maintain a stable net asset value could create a widespread risk of increased redemption pressures on all money market funds, potentially jeopardizing the stability of their net asset values. Certain money market funds have in the past failed to maintain stable net asset values, and there can be no assurance that such failures and resulting redemption pressures will not impact money market funds in the future.

Rules adopted by the Securities and Exchange Commission (the “SEC”) require, among other things, certain money market funds to cause transactions in shares of these funds to be effected using a fund’s net asset value per share calculated out to the fourth decimal point (e.g., $1.0000 instead of $1.00). “Government Money Market Funds” and “Retail Money Market Funds” as defined in Rule 2a-7 under the Investment Company Act of 1940, as amended, are not subject to the floating net asset value requirements, as described above. In addition, certain money market funds may impose a discretionary fee (up to 2%) upon sale of shares because of market conditions or other factors if a fund’s board or delegate believes such fee is in the best interest of the fund.

Recently adopted amendments to Rule 2a-7 will also require certain money market funds, excluding government money market funds and retail money market funds, to impose mandatory liquidity fees when a fund experiences net redemptions that exceed 5% of its net assets, unless the fund’s liquidity costs are de minimis (i.e., less than 1 basis point).

There can be no assurance that the Portfolio’s investments in money market funds are not adversely affected by reforms to money market regulation that may be adopted by the SEC or other regulatory authorities.

In addition to the fees and expenses that the Portfolio directly bears, the Portfolio indirectly bears the fees and expenses of any money market fund in which it invests.

Mortgage- and Asset-Backed Securities Risk. Rising interest rates tend to extend the duration of, or reduce the rate of prepayments on, both commercial mortgage-backed securities (“CMBS”) and residential mortgage-backed securities (“RMBS”), making them more sensitive to changes in interest rates (“extension risk”). As a result, in a period of rising interest rates, the price of mortgage-backed securities may fall, causing the Portfolio to exhibit additional volatility. Mortgage-backed securities are also subject to prepayment risk. When interest rates decline, borrowers may pay off their mortgages sooner than expected. This can reduce the Portfolio’s returns because the Portfolio will have to reinvest that money at lower prevailing interest rates. Investments in certain mortgage-backed securities, including those comprised of subprime mortgages, may be subject to a higher degree of credit risk, valuation risk, and liquidity risk than various other types of fixed-income securities. Additionally, although mortgage-backed securities are generally supported by some form of government or private guarantee and/or insurance, there is no assurance that guarantors or insurers will meet their obligations.

CMBS are subject to certain other risks. The market for CMBS developed more recently than that for RMBS and is relatively small in terms of outstanding principal amount of issues compared to the RMBS market. CMBS are also subject to risks associated with a lack of standardized terms, shorter maturities than residential mortgage loans, and payment of all or substantially all of the principal at maturity, rather than regular amortization of principal. Moreover, the type and use of a particular commercial property may add to the risk of CMBS investments. Adverse changes in economic conditions and circumstances are more likely to have an adverse impact on mortgage-backed securities secured by loans on commercial properties than on those secured by residential properties.

Similarly, the value of the Portfolio’s investments in asset-backed securities may be adversely affected by changes in interest rates, factors concerning the interests in and structure of the issuer or originator of the receivables, the creditworthiness of the entities that provide any supporting letters of credit, surety bonds, or other credit or liquidity enhancements, and/or the market’s assessment of the quality of the underlying assets. Generally, the originating bank or credit provider is neither the obligor nor the guarantor of the security, and interest and principal payments ultimately depend upon payment of the underlying loans by individuals. The Portfolio could incur a loss if the underlying loans are not paid. In addition, most asset-backed securities are subject to prepayment risk in a declining interest rate environment. The impact of prepayments on the

22 | Janus Aspen Series

value of asset-backed securities may be difficult to predict and may result in greater volatility. Rising interest rates tend to extend the duration of asset-backed securities, making them more volatile and sensitive to changing interest rates.

Private Placements and Other Exempt Securities Risk. Investments in private placements and other securities exempt from certain registration requirements could decrease the Portfolio’s liquidity profile or prevent the Portfolio from disposing of them promptly at advantageous prices. Private placements and other securities exempt from certain registration requirements may be less liquid than other investments because such securities may not always be readily sold in broad public markets and may have no active trading market. As a result, they may be difficult to value because market quotations may not be readily available. Transaction costs may be higher for these securities, and the Portfolio may get only limited information about the issuer of a private placement or other security exempt from certain registration requirements.

REIT and Real Estate-Related Securities Risk. To the extent the Portfolio holds REITs and REIT-like entities, it may be subject to the additional risks associated with REIT and REIT-like investments. REITs and REIT-like entities are subject to heavy cash flow dependency to allow them to make distributions to their shareholders. The prices of equity REITs are affected by changes in the value of the underlying property owned by the REITs, changes in capital markets and interest rates, management skill in running a REIT, and the creditworthiness of the REIT. The prices of mortgage REITs are affected by the quality of any credit they extend, the creditworthiness of the mortgages they hold, as well as by the value of the property that secures the mortgages. In addition, mortgage REITs (similar to direct investments in mortgage-backed securities) are subject to prepayment risk. Equity REITs and mortgage REITs are subject to heavy cash flow dependency, defaults by borrowers, and self-liquidation. There is also the risk that borrowers under mortgages held by a REIT or lessees of a property that a REIT owns may be unable to meet their obligations to the REIT. In the event of a default by a borrower or lessee, the REIT may incur substantial costs associated with protecting its investments. While equity REITs and mortgage REITs may provide exposure to a large number of properties, such properties may be concentrated in a particular industry, region, or housing type, making such investments more vulnerable to unfavorable developments to economic or market events. Certain “special purpose” REITs in which the Portfolio may invest focus their assets in specific real property sectors, such as hotels, shopping malls, nursing homes, or warehouses, and are therefore subject to the specific risks associated with adverse developments in these sectors. The Portfolio’s shareholders will indirectly bear their proportionate share of the REIT’s expenses, in addition to their proportionate share of the Portfolio’s expenses. The value of investments in REOCs will generally be affected by the same factors that adversely affect REIT investments; however, REOCs may also be adversely affected by income streams derived from businesses other than real estate ownership.

Additionally, a REIT that fails to comply with federal tax requirements affecting REITs may be subject to federal income taxation, or the federal tax requirement that a REIT distribute substantially all of its net income to its shareholders may result in a REIT having insufficient capital for future expenditures. REITs are also subject to certain provisions under federal tax law and the failure of a company to qualify as a REIT could have adverse consequences for the Portfolio, including significantly reducing the return to the Portfolio on its investment in such company.

Small- and Mid-Sized Companies Risk. The Portfolio’s investments in securities issued by small- and mid-sized companies, which can include smaller, start-up companies offering emerging products or services, may involve greater risks than are customarily associated with larger, more established companies. For example, small- and mid-sized companies may suffer more significant losses as a result of their narrow product lines, limited operating history, greater exposure to competitive threats, limited financial resources, limited trading markets, and the potential lack of management depth. Securities issued by small- and mid-sized companies tend to be more volatile and somewhat more speculative than securities issued by larger or more established companies and may underperform as compared to the securities of larger or more established companies. These holdings are also subject to wider price fluctuations and tend to be less liquid than stocks of larger or more established companies, which could have a significant adverse effect on the Portfolio’s returns, especially as market conditions change.

23 | Janus Aspen Series

reforms, achieve specified levels of economic performance, or repay principal or interest when due may result in the cancellation of third party commitments to lend funds to the sovereign debtor, which may further impair such debtor’s ability or willingness to timely service its debts. The Portfolio may be requested to participate in the rescheduling of such sovereign debt and to extend further loans to governmental entities, which may adversely affect the Portfolio’s holdings. In the event of default, there may be limited or no legal remedies for collecting sovereign debt and there may be no bankruptcy proceedings through which the Portfolio may collect all or part of the sovereign debt that a governmental entity has not repaid. In addition, to the extent the Portfolio invests in non-U.S. sovereign debt, it may be subject to currency risk.

TBA Commitments Risk. The Portfolio may enter into “to be announced” or “TBA” commitments. Although TBA commitments must meet industry-accepted “good delivery” standards, there can be no assurance that a security purchased on a forward commitment basis will ultimately be issued or delivered by the counterparty. If the counterparty to a transaction fails to deliver the securities, the Portfolio could suffer a loss. Because TBA commitments do not require the delivery of a specific security, the characteristics of a security delivered to the Portfolio may be less favorable than expected. There is a risk that the security that the Portfolio buys will lose value between the purchase and settlement dates. When the Portfolio sells a TBA security prior to settlement, it does not participate in future gains or losses with respect to the security. The Portfolio is generally not required to pay for the TBA security until the settlement date and, as a result, if the Portfolio remains substantially fully invested at a time when TBA commitment purchases are outstanding, the purchases may result in a form of leverage.

24 | Janus Aspen Series

Management of the Portfolio

Investment adviser

The Adviser (together with its predecessors and affiliates) has served as investment adviser to the Janus Henderson mutual funds since 1970 and currently serves as investment adviser to all of the Janus Henderson mutual funds as well as the Janus Henderson exchange-traded funds, acts as subadviser for a number of private-label mutual funds, and provides separate account advisory services for institutional accounts and other unregistered products.

The Trust and the Adviser have received an exemptive order from the SEC that permits the Adviser, subject to the approval of the Trustees, to appoint or replace certain subadvisers to manage all or a portion of the Portfolio’s assets and enter into, amend, or terminate a subadvisory agreement with certain subadvisers without obtaining shareholder approval (a “manager-of-managers structure”). The manager-of-managers structure applies to subadvisers that are not affiliated with the Trust or the Adviser (“non-affiliated subadvisers”), as well as any subadviser that is an indirect or direct “wholly-owned subsidiary” (as such term is defined by the Investment Company Act of 1940, as amended) of the Adviser or of another company that, indirectly or directly, wholly owns the Adviser (collectively, “wholly-owned subadvisers”).

Pursuant to the order, the Adviser, with the approval of the Trustees, has the discretion to terminate any subadviser and allocate and, as appropriate, reallocate the Portfolio’s assets among the Adviser and any other non-affiliated subadvisers or wholly-owned subadvisers (including terminating a non-affiliated subadviser and replacing it with a wholly-owned subadviser). To the extent that the Portfolio’s assets are allocated to one or more subadvisers, the Adviser, subject to oversight by the Trustees, would have the responsibility to oversee such subadviser(s) to the Portfolio and to recommend for approval by the Trustees, the hiring, termination, and replacement of a subadviser for the Portfolio. In the event that the Adviser hires a subadviser pursuant to the manager-of-managers structure, the Portfolio would provide shareholders with information about the subadviser and subadvisory agreement within 90 days.

The Adviser furnishes certain administration, compliance, and accounting services to the Portfolio, including providing office space for the Portfolio and providing personnel to serve as officers to the Portfolio. The Portfolio reimburses the Adviser for certain of its costs in providing these services (to the extent the Adviser seeks reimbursement and such costs are not otherwise waived). These costs include some or all of the salaries, fees, and expenses of the Adviser’s employees and Portfolio officers, including the Portfolio’s Chief Compliance Officer and compliance staff, that provide specified administration and compliance services to the Portfolio. The Portfolio pays these costs based on out-of-pocket expenses incurred by the Adviser, and these costs are separate and apart from advisory fees and other expenses paid in connection with the investment advisory services the Adviser provides to the Portfolio.

Management expenses

The Portfolio pays the Adviser an investment advisory fee and incurs expenses, including the distribution and shareholder servicing fees (12b-1 fee), administrative services fees payable pursuant to the Transfer Agency Agreement, any other transfer agent and custodian fees and expenses, legal and auditing fees, printing and mailing costs of sending reports and other information to existing shareholders, and Independent Trustees’ fees and expenses. The Portfolio’s investment advisory fee is calculated daily and paid monthly. The Portfolio’s advisory agreement details the investment advisory fee and other expenses that the Portfolio must pay.

The following table reflects the Portfolio’s contractual investment advisory fee rate (expressed as an annual rate), as well as the actual compensation rate paid by the Portfolio to the Adviser. The rate shown is a fixed rate based on the Portfolio’s average daily net assets.

Portfolio Name	Average Daily Net Assets of the Portfolio	Contractual Investment Advisory Fee (%) (annual rate)	Actual Compensation Rate Paid to Adviser (%) (for the fiscal year ended December 31, 2024)
Balanced Portfolio	All Asset Levels	0.55	0.55

25 | Janus Aspen Series

A discussion regarding the basis for the Trustees’ approval of the Portfolio’s investment advisory agreement is included in the Portfolio’s financial statements located in Form N-CSR for the periods ending December 31 and June 30. The Portfolio’s annual or semiannual financial statements are available, free of charge, at janushenderson.com/VIT or by contacting your plan sponsor, broker-dealer, or financial intermediary, or by contacting a Janus Henderson representative at 1-877-335-2687.

Fee Waiver

The Adviser has contractually agreed to waive and/or reimburse a portion of the Portfolio’s management fee in an amount equal to the management fee it earns as an investment adviser to any affiliated ETFs in which the Portfolio invests. Pursuant to this agreement, the waiver amount is equal to the amount of the Portfolio’s assets invested in the affiliated ETFs, multiplied by an amount equal to the current daily unitary management fee of the affiliated ETF, less certain asset-based operating fees and expenses incurred on a per-fund basis and paid by the Adviser with respect to the affiliated ETFs (including, but not limited to custody, sub-administration, transfer agency, legal, and audit fees).

This contractual waiver may be modified or terminated only at the discretion of the Board of Trustees. For information about how the fee waiver affects the total expenses of the Portfolio, if applicable, see the “Fees and Expenses of the Portfolio” table in the Portfolio Summary of the Prospectus. The Adviser has agreed to continue the waiver for at least a one-year period commencing on April 30, 2025.

Portfolio management

Balanced Portfolio

Co-Portfolio Managers Jeremiah Buckley, Michael Keough, and Greg Wilensky are responsible for the day-to-day management of the Portfolio. Messrs. Keough and Wilensky focus on the fixed-income portion of the Portfolio. Mr. Buckley focuses on the equity portion of the Portfolio.

Jeremiah Buckley, CFA, is Executive Vice President and Co-Portfolio Manager of Balanced Portfolio, which he has co-managed since December 2015. Mr. Buckley is also Portfolio Manager of other Janus Henderson accounts. He holds a Bachelor of Arts degree in Economics from Dartmouth College, where he graduated Phi Beta Kappa. He holds the Chartered Financial Analyst designation.

Michael Keough is Executive Vice President and Co-Portfolio Manager of Balanced Portfolio, which he has co-managed since December 2019. Mr. Keough is also Portfolio Manager of other Janus Henderson accounts. He holds a Bachelor of Science degree in Business/Management from the United States Air Force Academy.

Greg Wilensky, CFA, is Head of U.S. Fixed-Income of Janus Henderson Investors. He is Executive Vice President and Co-Portfolio Manager of Balanced Portfolio, which he has co-managed since February 2020. Mr. Wilensky is also Portfolio Manager of other Janus Henderson accounts. He holds a Bachelor of Science degree in Business Administration from Washington University and a Master of Business Administration degree from the University of Chicago. Mr. Wilensky holds the Chartered Financial Analyst designation.

Information about portfolio management’s compensation structure and other accounts managed, as well as the aggregate range of their individual ownership in the Portfolio(s) that they manage, is included in the SAI.

Conflicts of Interest

The Adviser manages other funds and numerous other accounts, which may include separate accounts and other pooled investment vehicles, such as hedge funds. Side-by-side management of multiple accounts, including the management of a cash collateral pool for securities lending and investing the Janus Henderson funds’ cash, may give rise to conflicts of interest among those accounts, and may create potential risks, such as the risk that investment activity in one account may adversely affect another account. For example, short sale activity in an account could adversely affect the market value of long positions in one or more other accounts (and vice versa). Side-by-side management may raise additional potential conflicts of interest relating to the allocation of investment opportunities and the aggregation and allocation of trades. A further discussion of potential conflicts of interest and a discussion of certain procedures intended to mitigate such potential conflicts are contained in the Portfolio’s SAI.

26 | Janus Aspen Series

Other information

Classes of Shares

Only Service Shares are offered by this Prospectus. The Shares are available only in connection with investment in and payments under variable insurance contracts, as well as certain qualified retirement plans, that require a fee from Portfolio assets to procure distribution and/or administrative services to contract owners and plan participants. Institutional Shares are offered only in connection with investment in and payments under variable insurance contracts, as well as certain qualified retirement plans. Because the expenses of each class may differ, the performance of each class is expected to differ. If you would like additional information about the Institutional Shares, please call 1-800-525-0020. In addition, for an analysis of fees associated with an investment in either share class or other similar funds, please visit www.finra.org/fundanalyzer.

Closed Portfolio Policies

The Portfolio may limit sales of its Shares to new investors. If sales of the Portfolio are limited, it is expected that existing shareholders invested in the Portfolio would be permitted to continue to purchase Shares through their existing Portfolio accounts and to reinvest any dividends or capital gains distributions in such accounts, absent highly unusual circumstances. Requests for new accounts into a closed portfolio would be reviewed by management, taking into consideration eligibility requirements and whether the addition to the portfolio is believed to negatively impact existing portfolio shareholders. The closed portfolio may decline opening new accounts, including eligible new accounts, if it would be in the best interests of the portfolio and its shareholders. If applicable, additional information regarding general policies and exceptions can be found in a closed portfolio’s prospectuses.

Liquidation/Reorganization of a Portfolio

It is important to know that, pursuant to the Trust’s Amended and Restated Trust Instrument, the Trustees have the authority to merge, liquidate, and/or reorganize a portfolio into another portfolio without seeking shareholder vote or consent.

DISTRIBUTION OF THE Portfolio

The Portfolio is distributed by Janus Henderson Distributors US LLC (the “Distributor”), which is a member of the Financial Industry Regulatory Authority, Inc. (“FINRA”). To obtain information about FINRA member firms and their associated persons, you may contact FINRA at www.finra.org, or 1-800-289-9999.

27 | Janus Aspen Series

Distributions and taxes

Distributions

To avoid taxation of the Portfolio, the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”) requires the Portfolio to distribute all or substantially all of its net investment income and any net capital gains realized on its investments at least annually. The Portfolio’s income from certain dividends, interest, and any net realized short-term capital gains are paid to shareholders as ordinary income dividends. Net realized long-term capital gains, if any, are paid to shareholders as capital gains distributions, regardless of how long Shares of the Portfolio have been held. A portion of the Portfolio’s distributions received from REITs may be classified as a return of capital for federal income tax purposes. As a result, the Portfolio is more likely to make distributions that are treated as returns of capital, and possibly in greater amounts, than a portfolio that does not invest in REITs. Distributions are made at the class level, so they may vary from class to class within a single portfolio.

Distribution Schedule

Dividends for the Portfolio are normally declared and distributed in June and December. Capital gains are normally declared and distributed in June. However, in certain situations it may be necessary for the Portfolio to declare and distribute capital gains in December. If necessary, dividends and net capital gains may be distributed at other times as well. Unless otherwise instructed, distributions of net investment income and net capital gains, if any, are automatically reinvested in additional Shares of the Portfolio.

How Distributions Affect the Portfolio’s NAV

Distributions are paid to shareholders as of the record date of a distribution of the Portfolio, regardless of how long the Shares have been held. Undistributed dividends and net capital gains are included in the Portfolio’s daily net asset value (“NAV”). The share price of the Portfolio drops by the amount of the distribution, net of any subsequent market fluctuations. For example, assume that on December 31, the Portfolio declared a dividend in the amount of $0.25 per share. If the Portfolio’s share price was $10.00 on December 30, the Portfolio’s share price on December 31 would be $9.75, barring market fluctuations.

TAXES

Taxes on Distributions

Because Shares of the Portfolio may be purchased only through variable insurance contracts and certain qualified retirement plans, it is anticipated that any income dividends or net capital gains distributions made by the Portfolio will be exempt from current federal income taxation if left to accumulate within the variable insurance contract or qualified retirement plan. Generally, withdrawals from such contracts or plans may be subject to federal income tax at ordinary income rates and, if withdrawals are made from a retirement plan before age 59 1∕2, a 10% penalty tax may be imposed. The federal income tax status of your investment depends on the features of your qualified retirement plan or variable insurance contract. Further information may be found in your plan documents or in the prospectus of the separate account offering such contract.

Taxation of the Portfolio

Dividends, interest, and some capital gains received by the Portfolio on foreign securities may be subject to foreign tax withholding or other foreign taxes. If the Portfolio is eligible, it may from year to year make the election permitted under Section 853 of the Internal Revenue Code to pass through such taxes to shareholders. If such an election is not made, any foreign taxes paid or accrued will represent an expense to the Portfolio.

The Portfolio does not expect to pay any federal income or excise taxes because it intends to meet certain requirements of the Internal Revenue Code. In addition, because the Shares of the Portfolio are sold in connection with variable insurance contracts, the Portfolio intends to satisfy the diversification requirements applicable to insurance company separate accounts under the Internal Revenue Code. If the Portfolio invests in partnerships, it may be subject to state tax liabilities.

28 | Janus Aspen Series

Shareholder’s guide

Investors may not purchase or redeem Shares of the Portfolio directly. Shares may be purchased or redeemed only through variable insurance contracts offered by the separate accounts of participating insurance companies or through certain qualified retirement plans. Refer to the prospectus for the participating insurance company’s separate account or your plan documents for instructions on purchasing or selling variable insurance contracts and on how to select the Portfolio as an investment option for a contract or a qualified retirement plan.

With certain exceptions, the Portfolio is generally available only to shareholders residing in the United States and employees of the Adviser or its affiliates. For purposes of this policy, the Portfolio requires that a shareholder and/or entity be a U.S. citizen residing in the United States or a U.S. Territory (including overseas U.S. military or diplomatic addresses) or a resident alien residing in the United States or a U.S. Territory with a valid U.S. Taxpayer Identification Number to open an account with the Portfolio.

Pricing of portfolio shares

The per share NAV for each class is computed by dividing the total value of assets allocated to the class, less liabilities allocated to that class, by the total number of outstanding shares of the class. The Portfolio’s NAV is calculated as of the close of the trading session of the New York Stock Exchange (“NYSE”) (normally 4:00 p.m. New York time) each day that the NYSE is open (“business day”). However, the time at which the Portfolio’s NAV is calculated may be changed if trading on the NYSE is restricted, the NYSE closes at a different time, or as permitted by the SEC. Foreign securities held by the Portfolio may be traded on days and at times when the NYSE is closed and the NAV is therefore not calculated. Accordingly, the value of the Portfolio’s holdings may change on days that are not business days in the United States and on which you will not be able to purchase or redeem the Portfolio’s Shares.

All purchases and redemptions will be duly processed at the NAV next calculated after a request is received in good order by the Portfolio or its agents. In order to receive a day’s price, an order must be received in good order by the Portfolio (or insurance company or plan sponsor) or its agents by the close of the trading session of the NYSE.

Portfolio holdings are valued in accordance with policies and procedures established by the Adviser pursuant to Rule 2a-5 under the Investment Company Act of 1940, as amended, and approved by and subject to the oversight of the Trustees (the “Valuation Procedures”). To the extent available, domestic and foreign equity securities traded on a securities exchange, including exchange-traded funds, are generally valued at readily available market quotations, which are (i) the official close prices or (ii) last sale prices on the primary market or exchange in which the securities trade. Most fixed-income securities are typically valued using an evaluated bid price supplied by an Adviser- approved pricing service that is intended to reflect market value. The evaluated bid price is an evaluation that may consider factors such as security prices, yields, maturities, and ratings. Certain short-term instruments maturing within 60 days or less may be valued at amortized cost, which approximates market value. If a market quotation or evaluated price for a security is not readily available or is deemed unreliable, or if an event that is expected to affect the value of the security occurs after the close of the principal exchange or market on which the security is traded, and before the close of the NYSE, a fair value of the security will be determined in good faith by the Adviser pursuant to the Valuation Procedures. Such events include, but are not limited to: (i) a significant event that may affect the securities of a single issuer, such as a merger, bankruptcy, or significant issuer-specific development; (ii) an event that may affect an entire market, such as a natural disaster or significant governmental action; (iii) a non-significant event such as a market closing early or not opening, or a security trading halt; and (iv) pricing of a non-valued security and a restricted or non-public security. This type of fair valuation may be more commonly used with foreign equity securities, but it may also be used with, among other things, thinly-traded domestic securities or fixed-income securities. Special valuation considerations may apply with respect to “odd-lot” fixed-income transactions which, due to their small size, may receive evaluated prices by pricing services which reflect a large block trade and not what actually could be obtained for the odd-lot position. For valuation purposes, quotations of foreign portfolio securities, other assets and liabilities, and forward contracts stated in foreign currency are generally translated into U.S. dollar equivalents at the prevailing market rates. The Valuation Procedures provide for the use of systematic fair valuation models provided by an independent pricing service to value foreign equity securities in order to adjust for stale pricing, which may occur between the close of certain foreign exchanges and the close of the NYSE. The methodologies employed when fair valuing Portfolio holdings may change from time to time. Because fair value pricing involves subjective judgments, it is possible that the fair value determination for a security may be different than the value that could be realized when selling that security.

Due to the subjective nature of systematic fair valuation, the value of a particular security may be different from the last quoted market price. Systematic fair valuation may reduce arbitrage activity involving the frequent buying and selling of

29 | Janus Aspen Series

mutual fund shares by investors seeking to take advantage of a perceived lag between a change in the value of the Portfolio’s securities and the reflection of such change in the Portfolio’s NAV, as further described in the “Excessive Trading” section of this Prospectus. While funds that invest in foreign securities may be at a greater risk for arbitrage activity, such activity may also arise in funds which do not invest in foreign securities, for example, when trading in a security held by a portfolio is halted and does not resume prior to the time the portfolio calculates its NAV (referred to as “stale pricing”). Portfolios that hold thinly-traded securities, such as certain small-capitalization securities or high-yield fixed-income securities, may be subject to attempted use of arbitrage techniques. To the extent that the valuation of a security is different from the security’s market value, short-term arbitrage traders buying and/or selling shares of the Portfolio may dilute the NAV of the Portfolio, which negatively impacts long-term shareholders. The Valuation Procedures and the Trust’s excessive trading policies and procedures may not completely eliminate short-term trading in certain omnibus accounts and other accounts traded through intermediaries.

The value of the securities of other mutual funds held by the Portfolio, if any, will be calculated using the NAV of such mutual funds, and the prospectuses for such mutual funds explain the circumstances under which they use fair valuation and the effects of using fair valuation.

Generally, futures contracts and/or options on futures are valued at the actual settlement price on valuation date on the exchange as reported by an approved vendor. In the event actual settlement price is unavailable or is deemed unreliable, then the reported settlement price (there can be different settlement prices at different times), early settlement price or the last trade price shall be used. Option contracts are valued using an evaluated price from an approved vendor. Evaluated prices can be derived using an option pricing model, including inputs derived from volatility surfaces, market data and characteristics of the portfolio investment. In cases when an approved vendor cannot provide coverage for an option, a broker quotation or an internal valuation using the Black-Scholes model, or other appropriate option pricing model shall be used. Index swaps, credit default swaps, and interest rate swaps are typically valued using an evaluated price from an approved vendor. Evaluated prices will generally have a fixed and floating leg with the present value of each being calculated based on the terms of the trade.

Distribution, servicing, and administrative fees

Distribution and Shareholder Servicing Plan

Under a distribution and shareholder servicing plan (the “Plan”) adopted in accordance with Rule 12b-1 under the Investment Company Act of 1940, as amended, the Shares may pay the Distributor a fee at an annual rate of up to 0.25% of the average daily net assets of the Shares of the Portfolio. Under the terms of the Plan, the Trust is authorized to make payments to the Distributor for remittance to insurance companies and qualified plan service providers as compensation for distribution and/or administrative services performed by such entities. Because 12b-1 fees are paid out of the Portfolio’s assets on an ongoing basis, over time they will increase the cost of your investment and may cost you more than paying other types of sales charges.

Administrative Fees

The Transfer Agent receives an administrative services fee at an annual rate of 0.05% of the average daily net assets of the Portfolio for arranging for the provision by participating insurance companies and qualified plan service providers of administrative services, including recordkeeping, subaccounting, order processing, or other shareholder services provided on behalf of contract holders or plan participants investing in the Portfolio. Other shareholder services may include the provision of order confirmations, periodic account statements, forwarding prospectuses, shareholder reports, and other materials to existing customers, and answering inquiries regarding accounts. The Transfer Agent expects to use this entire fee to compensate insurance companies and qualified plan service providers for providing these services to their customers who invest in the Portfolio.

Payments to financial intermediaries by the Adviser or its affiliates

From its own assets, the Adviser or its affiliates pay fees to selected insurance companies, qualified plan service providers or their affiliates, or other financial intermediaries that distribute, market, or promote the Portfolio or perform related services for contract owners and plan participants. The amount of these payments is determined from time to time by the Adviser, may be substantial, and may differ for different financial intermediaries. The Adviser and its affiliates consider a number of factors in making payments to financial intermediaries.

30 | Janus Aspen Series

The Adviser or its affiliates pay fees, from their own assets, to selected insurance companies, qualified plan service providers, and other financial intermediaries for providing recordkeeping, subaccounting, transaction processing, and other shareholder or administrative services (including payments for processing transactions via the National Securities Clearing Corporation (“NSCC”) or other means) in connection with investments in the Janus Henderson funds. These fees are in addition to any fees that may be paid by the Janus Henderson funds for these types of services or other services.

In addition, the Adviser or its affiliates periodically share certain marketing expenses with selected intermediaries, or pay for or sponsor informational meetings, seminars, client awareness events, support for marketing materials, sales reporting, or business building programs for such intermediaries to raise awareness of the Portfolio. The Adviser or its affiliates make payments to participate in selected intermediary marketing support programs which may provide the Adviser or its affiliates with one or more of the following benefits: attendance at sales conferences, participation in meetings or training sessions, access to or information about intermediary personnel, use of an intermediary’s marketing and communication infrastructure, fund analysis tools, data, business planning and strategy sessions with intermediary personnel, information on industry- or platform-specific developments, trends and service providers, and other marketing-related services. Such payments may be in addition to, or in lieu of, the fees described above. These payments are intended to promote the sales of Janus Henderson funds and to reimburse financial intermediaries, directly or indirectly, for the costs that they or their salespersons incur in connection with educational seminars, meetings, and training efforts about the Janus Henderson funds to enable the intermediaries and their salespersons to make suitable recommendations, provide useful services, and maintain the necessary infrastructure to make the Janus Henderson funds available to their customers.

The receipt of (or prospect of receiving) fees or reimbursements and other forms of compensation described above may provide a financial intermediary and its salespersons with an incentive to favor sales of Janus Henderson funds’ shares over sales of other mutual funds (or non-mutual fund investments) or to favor sales of one class of Janus Henderson funds’ shares over sales of another Janus Henderson funds’ share class, with respect to which the financial intermediary does not receive such payments or receives them in a lower amount. The receipt of these payments may cause certain financial intermediaries to elevate the prominence of the Janus Henderson funds within such financial intermediary’s organization by, for example, placement on a list of preferred or recommended funds and/or the provision of preferential or enhanced opportunities to promote the Janus Henderson funds in various ways within such financial intermediary’s organization.

From time to time, certain financial intermediaries approach the Adviser to request that the Adviser make contributions to certain charitable organizations. In these cases, the Adviser’s contribution may result in the financial intermediary, or its salespersons, recommending Janus Henderson funds over other mutual funds (or non-mutual fund investments).

The payment arrangements described above will not change the price a contract owner or plan participant pays for Shares nor the amount that a Janus Henderson fund receives to invest on behalf of the contract owner or plan participant. You should consider whether such arrangements exist when evaluating any recommendations from an intermediary to purchase or sell Shares of the Portfolio and, if applicable, when considering which share class of the Portfolio is most appropriate for you. Please contact your insurance company or plan sponsor for details on such arrangements.

Purchases

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Refer to the prospectus of the appropriate insurance company separate account or your plan documents for information on how to invest in the Shares of the Portfolio. Under certain circumstances, the Portfolio may permit an in-kind purchase of Shares. Participating insurance companies and certain other designated organizations are authorized to receive purchase orders on the Portfolio’s behalf. As discussed under “Payments to Financial Intermediaries by the Adviser or its Affiliates,” the Adviser and its affiliates make payments to selected insurance companies, qualified plan service providers, or their affiliates, or other financial intermediaries that were instrumental in the acquisition or retention of accounts for the Portfolio or that provide services in connection with investments in the Portfolio. You should consider such arrangements when evaluating any recommendation of the Portfolio.

The Portfolio reserves the right to reject any purchase order, including exchange purchases, for any reason. The Portfolio is not intended for excessive trading. For more information about the Portfolio’s policy on excessive trading, refer to “Excessive Trading.”

The Portfolio may discontinue sales to a qualified plan and require plan participants with existing investments in the Shares to redeem those investments if the plan loses (or in the opinion of the Adviser, is at risk of losing) its qualified plan status.

31 | Janus Aspen Series

In compliance with the Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act of 2001 (“USA PATRIOT Act”), your insurance company or plan sponsor is required to verify certain information on your account application as part of its Anti-Money Laundering Program. You will be required to provide your full name, date of birth, Social Security number, and permanent street address to assist in verifying your identity. You may also be asked to provide documents that may help to establish your identity. Until verification of your identity is made, your insurance company or plan sponsor may temporarily limit additional share purchases. In addition, your insurance company or plan sponsor may close an account if they are unable to verify a shareholder’s identity. Please contact your insurance company or plan sponsor if you need additional assistance when completing your application or additional information about the insurance company or plan sponsor’s Anti-Money Laundering Program.

In an effort to ensure compliance with this law, the Adviser’s Anti-Money Laundering Program (the “Program”) provides for the development of internal practices, procedures and controls, designation of anti-money laundering compliance officers, an ongoing training program, and an independent audit function to determine the effectiveness of the Program.

Potential Conflicts

Although the Portfolio does not currently anticipate any disadvantages to policy owners because the Portfolio offers its Shares to unaffiliated variable annuity and variable life separate accounts of insurance companies that are unaffiliated with the Adviser and to certain qualified retirement plans, there is a possibility that a material conflict may arise. The Trustees monitor events in an effort to identify any disadvantages or material irreconcilable conflicts and to determine what action, if any, should be taken in response. If a material disadvantage or conflict is identified, the Trustees may require one or more insurance company separate accounts or qualified plans to withdraw its investments in the Portfolio or substitute Shares of another portfolio. If this occurs, the Portfolio may be forced to sell its securities at disadvantageous prices. In addition, the Portfolio may refuse to sell its Shares to any separate account or qualified plan or may suspend or terminate the offering of the Portfolio’s Shares if such action is required by law or regulatory authority or is in the best interests of the Portfolio’s shareholders. It is possible that a qualified plan investing in the Portfolio could lose its qualified plan status under the Internal Revenue Code, which could have adverse tax consequences on insurance company separate accounts investing in the Portfolio. The Adviser intends to monitor such qualified plans, and the Portfolio may discontinue sales to a qualified plan and require plan participants with existing investments in the Portfolio to redeem those investments if a plan loses (or in the opinion of the Adviser is at risk of losing) its qualified plan status.

Redemptions

Redemptions, like purchases, may be effected only through the separate accounts of participating insurance companies or through certain qualified retirement plans. Please refer to the appropriate separate account prospectus or plan documents for details.

Shares of the Portfolio may be redeemed on any business day on which the Portfolio’s NAV is calculated. Redemptions are duly processed at the NAV next calculated after your redemption order is received in good order by the Portfolio or its agents. Redemption proceeds will normally be sent within two business days following receipt of the redemption order. The Portfolio typically expects to meet redemption requests by paying out proceeds from cash or cash equivalent portfolio holdings, or by selling portfolio holdings. In stressed market conditions, and other appropriate circumstances, redemption methods may include borrowing funds or redeeming in-kind.

The Portfolio reserves the right to postpone payment of redemption proceeds for up to seven calendar days. Additionally, the right to require the Portfolio to redeem its Shares may be suspended, or the date of payment may be postponed beyond seven calendar days, whenever: (i) trading on the NYSE is restricted, as determined by the SEC, or the NYSE is closed (except for holidays and weekends); (ii) the SEC permits such suspension and so orders; or (iii) an emergency exists as determined by the SEC so that disposal of securities or determination of NAV is not reasonably practicable.

Large Shareholder Redemptions

Certain large shareholders, such as other portfolios, participating insurance companies, accounts, and affiliates of the Adviser, may from time to time own (beneficially or of record) or control a significant percentage of the Portfolio’s Shares. Redemptions by these large shareholders of their holdings in the Portfolio may cause the Portfolio to sell securities at times when it would not otherwise do so, which may negatively impact the Portfolio’s NAV and liquidity. Similarly, large Portfolio share purchases may adversely affect the Portfolio’s performance to the extent that the Portfolio is delayed in investing new cash and is required to maintain a larger cash position than it ordinarily would. A large shareholder purchase or redemption

32 | Janus Aspen Series

may also increase transaction costs. In addition, a large redemption could result in the Portfolio’s current expenses being allocated over a smaller asset base, which could lead to an increase in the Portfolio’s expense ratio.

Redemptions In-Kind

Shares normally will be redeemed for cash, although the Portfolio retains the right to redeem some or all of its shares in-kind under unusual circumstances, in order to protect the interests of remaining shareholders, to accommodate a request by a particular shareholder that does not adversely affect the interests of the remaining shareholders, or in connection with the liquidation of a portfolio, by delivery of securities selected from its assets at its discretion. However, the Portfolio is required to redeem shares solely for cash up to the lesser of $250,000 or 1% of the NAV of the Portfolio during any 90-day period for any one shareholder. Should redemptions by any shareholder exceed such limitation, the Portfolio will have the option of redeeming the excess in cash or in-kind. In-kind payment means payment will be made in portfolio securities rather than cash, and may potentially include illiquid investments. Illiquid investments may not be able to be sold quickly or at a price that reflects full value, or there may not be a market for such investments, which could cause the redeeming shareholder to realize losses on the investment if it is sold at a price lower than that at which it had been valued. If the Portfolio makes an in-kind payment, the redeeming shareholder might incur brokerage or other transaction costs to convert the securities to cash, whereas such costs are borne by the Portfolio for cash redemptions.

While the Portfolio may pay redemptions in-kind, the Portfolio may instead choose to raise cash to meet redemption requests through the sale of portfolio securities or permissible borrowings. If the Portfolio is forced to sell securities at an unfavorable time and/or under unfavorable conditions, such sales may adversely affect the Portfolio’s NAV and may increase brokerage costs.

Excessive trading

Excessive and Short-Term Trading Policies and Procedures

The Trustees have adopted policies and procedures with respect to short-term and excessive trading of Portfolio shares (“excessive trading”). The Portfolio is intended for long-term investment purposes, and the Portfolio will take reasonable steps to attempt to detect and deter short-term and excessive trading. Transactions placed in violation of the Portfolio’s excessive trading policies and procedures may be cancelled or rescinded by the Portfolio by the next business day following receipt by the Portfolio. The trading history of accounts determined to be under common ownership or control within any of the Janus Henderson funds may be considered in enforcing these policies and procedures.

The Janus Henderson funds attempt to deter excessive trading through at least the following methods:

•

fair valuation of securities as described under “Pricing of Portfolio Shares”; and

•

trade monitoring.

The Portfolio monitors for patterns of shareholder short-term trading and may suspend or permanently terminate the purchase and exchange privilege (if permitted by your insurance company or plan sponsor) of any investor who is identified as having a pattern of short-term trading. The Portfolio at all times reserves the right to reject any purchase or exchange request and to modify or terminate the purchase and exchange privileges for any investor for any reason without prior notice, in particular, if the trading activity in the account(s) is deemed to be disruptive to the Portfolio.

The Portfolio’s Trustees may approve from time to time a redemption fee to be imposed by any Janus Henderson fund, subject to 60 days’ notice to shareholders of that fund.

Investors in other share classes who place transactions through the same insurance company or plan sponsor on an omnibus basis may be deemed part of a group for the purpose of the Portfolio’s excessive trading policies and procedures and may be rejected in whole or in part by the Portfolio. Transactions accepted by an insurance company or plan sponsor in violation of the Portfolio’s excessive trading policies may be cancelled or revoked by the Portfolio by the next business day following receipt by the Portfolio.

In an attempt to deter excessive trading in omnibus accounts, the Portfolio or its agents may require intermediaries to impose restrictions on the trading activity of accounts traded through those intermediaries. Such restrictions may include, but are not limited to, requiring that trades be placed by U.S. mail, prohibiting future purchases by investors who have recently redeemed Portfolio shares, requiring intermediaries to report information about customers who purchase and redeem large amounts, and similar restrictions. The Portfolio’s ability to impose such restrictions with respect to accounts traded through

33 | Janus Aspen Series

particular intermediaries may vary depending on the systems’ capabilities, applicable contractual and legal restrictions, and cooperation of those intermediaries.

Generally, the Portfolio’s excessive trading policies and procedures do not apply to (i) a money market fund, although money market funds at all times reserve the right to reject any purchase request (including exchange purchases, if permitted by your insurance company or plan sponsor) for any reason without prior notice; (ii) transactions in the Janus Henderson funds by a Janus Henderson “fund of funds”; (iii) periodic rebalancing and identifiable transactions by certain funds of funds and asset allocation programs to realign portfolio investments with existing target allocations; and (iv) systematic purchase, exchange, or redemption programs.

The Portfolio’s policies and procedures regarding excessive trading may be modified at any time by the Portfolio’s Trustees.

Excessive Trading Risks

Excessive trading may present risks to the Portfolio’s long-term shareholders. Excessive trading into and out of the Portfolio may disrupt portfolio investment strategies, may create taxable gains to remaining Portfolio shareholders, and may increase Portfolio expenses, all of which may negatively impact investment returns for all remaining shareholders, including long-term shareholders.

Portfolios that invest in foreign securities may be at a greater risk for excessive trading. Investors may attempt to take advantage of anticipated price movements in securities held by a portfolio based on events occurring after the close of a foreign market that may not be reflected in the portfolio’s NAV (referred to as “price arbitrage”). Such arbitrage opportunities may also arise in portfolios which do not invest in foreign securities, for example, when trading in a security held by a portfolio is halted and does not resume prior to the time the portfolio calculates its NAV (referred to as “stale pricing”). Portfolios that hold thinly-traded securities, such as certain small-capitalization securities, may be subject to attempted use of arbitrage techniques. To the extent that the Portfolio’s valuation of a security differs from the security’s market value, short-term arbitrage traders may dilute the NAV of the Portfolio, which negatively impacts long-term shareholders. There is potential for short-term arbitrage trades to dilute the value of the shares held by the Portfolio despite the Portfolio’s adoption of policies and procedures intended to reduce the Portfolio’s exposure to price arbitrage, stale pricing, and other potential pricing inefficiencies.

There is no assurance that the policies and procedures adopted by the Portfolio to detect and deter excessive trading will be effective in all circumstances. For example, the Portfolio may be unable to completely eliminate the possibility of excessive trading in certain omnibus accounts and other accounts traded through intermediaries. Omnibus accounts may effectively conceal the identity of individual investors and their transactions from the Portfolio and its agents. This makes the Portfolio’s identification of excessive trading transactions in the Portfolio through an omnibus account difficult and makes the elimination of excessive trading in the account impractical without the assistance of the intermediary. Moreover, the contract between an insurance company and the owner of a variable insurance contract may govern the frequency with which the contract owner may cause the insurance company to purchase or redeem shares of the Portfolio. Although the Portfolio encourages intermediaries to take necessary actions to detect and deter excessive trading, some intermediaries may be unable or unwilling to do so, and accordingly, the Portfolio cannot eliminate completely the possibility of excessive trading.

Shareholders that invest through an omnibus account should be aware that they may be subject to the policies and procedures of their insurance company or plan sponsor with respect to excessive trading in the Portfolio.

Availability of Portfolio Holdings Information

The Mutual Fund Holdings Disclosure Policies and Procedures adopted by the Adviser and all mutual funds managed within the Janus Henderson fund complex are designed to be in the best interests of the portfolios and to protect the confidentiality of the portfolios’ holdings. The following describes policies and procedures with respect to disclosure of portfolio holdings.

•

Full Holdings. A schedule of the Portfolio’s holdings, consisting of at least the names of the holdings, is generally available on a monthly basis with a 30-day lag and is posted under Full Holdings for the Portfolio at janushenderson.com/VIT. A complete schedule of the Portfolio’s holdings is also available in the annual and semiannual financial statements located in Form N-CSR and, after the first and third fiscal quarters, in Form N-PORT. Information reported in Form N-CSR and in Form N-PORT will be made publicly available within 70 and 60 days, respectively, after the end of each fiscal quarter. The Portfolio’s Form N-CSR and Form N-PORT filings are available on the SEC’s website at http://www.sec.gov.

34 | Janus Aspen Series

•

Top Holdings. The Portfolio’s top portfolio holdings, in order of position size and as a percentage of the Portfolio’s total portfolio, are available monthly with a 15-day lag.

•

Other Information. The Portfolio may occasionally provide security breakdowns (e.g., industry, sector, regional, market capitalization, and asset allocation) and specific portfolio level performance attribution information and statistics monthly with a 15-day lag. Top/bottom equity securities and fixed-income issuers ranked by performance attribution, including the percentage attribution to Portfolio performance, average Portfolio weighting, and other relevant data points, may be provided monthly with a 15-day lag.

The Adviser may exclude from publication on its websites all or any portion of portfolio holdings or change the time periods of disclosure as deemed necessary to protect the interests of the Janus Henderson funds. Under extraordinary circumstances, exceptions to the Mutual Fund Holdings Disclosure Policies and Procedures may be made by the head of the applicable investment unit or a delegate, in consultation with the Portfolio’s Chief Compliance Officer or a delegate. Such exceptions may be made without prior notice to shareholders. A summary of the Portfolio’s holdings disclosure policies and procedures, which includes a discussion of any exceptions, is contained in the Portfolio’s SAI.

Shareholder communications

Your insurance company or plan sponsor is responsible for providing annual and semiannual reports, including the financial statements of the Portfolio. Please contact your insurance company or plan sponsor to obtain these reports. The Trust’s fiscal year ends December 31.

35 | Janus Aspen Series

Financial highlights

The financial highlights table is intended to help you understand the Portfolio’s financial performance for the period ended December 31 of the fiscal years shown. Items “Net asset value, beginning of period” through “Net asset value, end of period” reflect financial results for a single Portfolio Share. The gross expense ratio reflects expenses prior to any expense offset arrangement and waivers (reimbursements), if applicable. The net expense ratio reflects expenses after any expense offset arrangement and waivers (reimbursements), if applicable. The information shown for the fiscal years ended December 31 has been audited by PricewaterhouseCoopers LLP, whose report, along with the Portfolio’s financial statements, is included in the Portfolio’s Form N-CSR and is incorporated by reference into the SAI.

The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in the Service Shares of the Portfolio (assuming reinvestment of all dividends and distributions) but do not include charges and expenses attributable to any insurance product. If these charges and expenses had been included, the performance for the years shown would be lower. “Total return” information may include adjustments in accordance with generally accepted accounting principles. As a result, returns may differ from returns for shareholder transactions.

Balanced Portfolio – Service Shares

	Years ended December 31
	2024	2023	2022	2021	2020
Net Asset Value, Beginning of Period	$48.05	$42.48	$53.15	$46.11	$41.70
Income/(Loss) from Investment Operations:
Net investment income/(loss)(1)	0.96	0.85	0.48	0.32	0.54
Net realized and unrealized gain/(loss)	6.31	5.54	(9.32)	7.42	5.15
Total from Investment Operations	7.27	6.39	(8.84)	7.74	5.69
Less Dividends and Distributions:
Dividends (from net investment income)	(0.93)	(0.82)	(0.45)	(0.33)	(0.64)
Distributions (from capital gains)	—	—	(1.38)	(0.37)	(0.64)
Total Dividends and Distributions	(0.93)	(0.82)	(1.83)	(0.70)	(1.28)
Net Asset Value, End of Period	$54.39	$48.05	$42.48	$53.15	$46.11
Total Return*	15.15%	15.11%	(16.61)%	16.91%	14.05%
Net Assets, End of Period (in thousands)	$8,626,813	$7,961,766	$7,082,759	$8,272,771	$6,217,051
Ratios to Average Net Assets
Ratio of Gross Expenses	0.87%	0.87%	0.86%	0.86%	0.87%
Ratio of Net Expenses (After Waivers and Expense Offsets)	0.87%	0.87%	0.86%	0.86%	0.87%
Ratio of Net Investment Income/(Loss)	1.83%	1.89%	1.09%	0.65%	1.28%
Portfolio Turnover Rate(2)	83%	97%	89%	56%	80%

*	Total return includes adjustments in accordance with generally accepted accounting principles required at the year or period end and are not annualized for periods of less than one full year. Total return does not include fees, charges, or expenses imposed by the variable annuity and life insurance contracts for which Janus Aspen Series serves as an underlying investment vehicle.
(1)	Per share amounts are calculated based on average shares outstanding during the year or period.
(2)	Portfolio Turnover Rate excludes TBA (to be announced) purchase and sales commitments.

36 | Janus Aspen Series

Glossary of investment terms

This glossary provides a more detailed description of some of the types of securities, investment strategies, and other instruments in which the Portfolio may invest, as well as some general investment terms. The Portfolio may invest in these instruments to the extent permitted by its investment objective and policies. The Portfolio is not limited by this discussion and may invest in any other types of instruments not precluded by the policies discussed elsewhere in this Prospectus.

Equity and Debt Securities

Bank loans include institutionally-traded floating and fixed-rate debt securities generally acquired as a participation interest in or assignment of a loan originated by a lender or financial institution. Assignments and participations involve credit, interest rate, and liquidity risk. Interest rates on floating rate securities adjust with interest rate changes and/or issuer credit quality.

Bonds are debt securities issued by a company, municipality, government, or government agency. The issuer of a bond is required to pay the holder the amount of the loan (or par value of the bond) at a specified maturity and to make scheduled interest payments.

Common stocks are equity securities representing shares of ownership in a company and usually carry voting rights and earn dividends. Unlike preferred stock, dividends on common stock are not fixed but are declared at the discretion of the issuer’s board of directors.

Convertible securities are preferred stocks or bonds that pay a fixed dividend or interest payment and are convertible into common stock at a specified price or conversion ratio.

Credit Risk Transfer Securities (“CRTs”) are unguaranteed and unsecured fixed or floating rate general obligations that are commonly issued by government sponsored enterprises. CRTs are not directly linked to or backed by the underlying mortgage loans, so investors such as the Portfolio have no direct recourse to the underlying mortgage loans in the event of a default.

Debt securities are securities representing money borrowed that must be repaid at a later date. Such securities have specific maturities and usually a specific rate of interest or an original purchase discount.

Depositary receipts are receipts for shares of a foreign-based corporation that entitle the holder to dividends and capital gains on the underlying security. Receipts include those issued by domestic banks (American Depositary Receipts), foreign banks (Global or European Depositary Receipts), and broker-dealers (depositary shares).

Duration is a measurement of price sensitivity to interest rate changes. Unlike average maturity, duration reflects both principal and interest payments. Generally, the higher the coupon rate on a bond, the lower its duration will be. The duration of a bond portfolio is calculated by averaging the duration of bonds held by the Portfolio with each duration “weighted” according to the percentage of net assets that it represents. Because duration accounts for interest payments, the Portfolio’s duration is usually shorter than its average maturity. Securities with longer durations tend to be more sensitive to changes in interest rates, and are usually more volatile than securities with shorter duration. For example, the price of a bond portfolio with an average duration of five years would be expected to fall approximately 5% if interest rates rose by one percentage point. The Portfolio with a longer portfolio duration is more likely to experience a decrease in its share price as interest rates rise.

Equity securities generally include domestic and foreign common stocks; preferred stocks; securities convertible into common stocks or preferred stocks; warrants to purchase common or preferred stocks; and other securities with equity characteristics.

Exchange-traded funds (“ETFs”) are typically open-end investment companies, which may seek to track the performance of a specific index or be actively managed. ETFs are traded on a national securities exchange at market prices that may vary from the net asset value of their underlying investments.

Fixed-income securities are securities that pay a specified rate of return. The term generally includes short-and long-term government, corporate, and municipal obligations that pay a specified rate of interest, dividends, or coupons for a specified period of time. Coupon and dividend rates may be fixed for the life of the issue or, in the case of adjustable and floating rate securities, for a shorter period.

High-yield bonds are bonds that are rated below investment grade by the primary rating agencies (i.e., BB+ or lower by Standard & Poor’s and Fitch, or Ba1 or lower by Moody’s). Other terms commonly used to describe such bonds include “lower rated bonds,” “non-investment grade bonds,” and “junk bonds.”

37 | Janus Aspen Series

Mortgage- and asset-backed securities are shares in a pool of mortgages or other debt instruments. These securities are generally pass-through securities, which means that principal and interest payments on the underlying securities (less servicing fees) are passed through to shareholders on a pro rata basis.

Municipal securities are bonds or notes issued by a U.S. state or political subdivision. A municipal security may be a general obligation backed by the full faith and credit (i.e., the borrowing and taxing power) of a municipality or a revenue obligation paid out of the revenues of a designated project, facility, or revenue source.

Passive foreign investment companies (“PFICs”) are any foreign corporations which generate certain amounts of passive income or hold certain amounts of assets for the production of passive income. Passive income includes dividends, interest, royalties, rents, and annuities. To avoid taxes and interest that the Portfolio must pay if these investments are profitable, the Portfolio may make various elections permitted by the tax laws. These elections could require that the Portfolio recognize taxable income, which in turn must be distributed, before the securities are sold and before cash is received to pay the distributions.

Preferred stocks are equity securities that generally pay dividends at a specified rate and have preference over common stock in the payment of dividends and liquidation. Preferred stock generally does not carry voting rights.

Private placements are securities that are subject to legal and/or contractual restrictions on their sales. These securities may not be listed on an exchange and may have no active trading market. As a result of the absence of a public trading market, the prices of these securities may be more volatile and more difficult to determine than publicly traded securities and these securities may involve heightened risk as compared to investments in securities of publicly traded companies.

Real estate investment trust (“REIT”) is an investment trust that operates through the pooled capital of many investors who buy its shares. Investments are in direct ownership of either income property or mortgage loans. A REIT may be listed on an exchange or traded over-the-counter.

Rule 144A securities are securities that are not registered for sale to the general public under the Securities Act of 1933, as amended, but that may be resold to certain institutional investors.

Senior securities are securities that rank above an issuing company’s other securities in the event of a bankruptcy or liquidation, which means the Portfolio would be in line to receive repayment of its investment before certain of the company’s other creditors.

“To be announced” or “TBA” commitments are forward agreements for the purchase or sale of securities, including mortgage-backed securities, for a fixed price, with payment and delivery on an agreed upon future settlement date. The specific securities to be delivered are not identified at the trade date. However, delivered securities must meet specified terms, including issuer, rate, and mortgage terms. At the time the TBA commitment is made, the transaction is recorded and thereafter the value of such securities is reflected each day in determining the Portfolio’s net asset value. Because the Portfolio is generally not required to pay for the security until the settlement date, if the Portfolio remains substantially fully invested at a time when TBA commitment purchases are outstanding, the purchases may result in a form of leverage.

U.S. Government securities include direct obligations of the U.S. Government that are supported by its full faith and credit. Treasury bills have initial maturities of less than one year, Treasury notes have initial maturities of one to ten years, and Treasury bonds may be issued with any maturity but generally have maturities of at least ten years. U.S. Government securities also include indirect obligations of the U.S. Government that are issued by federal agencies and government sponsored entities. Unlike Treasury securities, agency securities generally are not backed by the full faith and credit of the U.S. Government. Some agency securities are supported by the right of the issuer to borrow from the Treasury, others are supported by the discretionary authority of the U.S. Government to purchase the agency’s obligations, and others are supported only by the credit of the sponsoring agency.

Variable and floating rate securities have variable or floating rates of interest and, under certain limited circumstances, may have varying principal amounts. Variable and floating rate securities pay interest at rates that are adjusted periodically according to a specified formula, usually with reference to some interest rate index or market interest rate. The floating rate tends to decrease the security’s price sensitivity to changes in interest rates.

Warrants are securities, typically issued with preferred stock or bonds, which give the holder the right to buy a proportionate amount of common stock at a specified price. The specified price is usually higher than the market price at the time of issuance of the warrant. The right may last for a period of years or indefinitely.

38 | Janus Aspen Series

Futures, Options, and Other Derivatives

Credit default swaps are a specific kind of counterparty agreement that allows the transfer of third party credit risk from one party to the other. One party in the swap is a lender and faces credit risk from a third party, and the counterparty in the credit default swap agrees to insure this risk in exchange for regular periodic payments.

Currency swaps involve the exchange of payments denominated in one currency for payments denominated in another. Payments are based on a notional principal amount, the value of which is fixed in exchange rate terms at the swap’s inception.

Derivatives are instruments that have a value derived from, or directly linked to, an underlying asset (stock, bond, commodity, currency, interest rate or market index). Types of derivatives can include, but are not limited to options, forward currency contracts, swaps, and futures contracts.

Equity-linked structured notes are derivative securities which are specially designed to combine the characteristics of one or more underlying securities and their equity derivatives in a single note form. The return and/or yield or income component may be based on the performance of the underlying equity securities, an equity index, and/or option positions. Equity-linked structured notes are typically offered in limited transactions by financial institutions in either registered or non-registered form.

Equity swaps involve the exchange by two parties of future cash flow (e.g., one cash flow based on a referenced interest rate and the other based on the performance of stock or a stock index).

Forward contracts are contracts to purchase or sell a specified amount of a financial instrument for an agreed upon price at a specified time. Forward contracts are not currently exchange-traded and are typically negotiated on an individual basis. The Portfolio may enter into forward currency contracts for investment purposes or to hedge against declines in the value of securities denominated in, or whose value is tied to, a currency other than the U.S. dollar or to reduce the impact of currency appreciation on purchases of such securities. It may also enter into forward contracts to purchase or sell securities or other financial indices.

Futures contracts are contracts that obligate the buyer to receive and the seller to deliver an instrument or money at a specified price on a specified date. The Portfolio may buy and sell futures contracts on foreign currencies, securities, and financial indices including indices of U.S. Government, foreign government, equity, or fixed-income securities. Futures contracts are standardized and traded on designated exchanges.

Indexed/structured securities are typically short- to intermediate-term debt securities whose value at maturity or interest rate is linked to currencies, interest rates, equity securities, indices, commodity prices, or other financial indicators. Such securities may be positively or negatively indexed (e.g., their value may increase or decrease if the reference index or instrument appreciates). Indexed/structured securities may have return characteristics similar to direct investments in the underlying instruments and may be more volatile than the underlying instruments.

Inflation index swaps involve the exchange by the Portfolio with another party of its respective commitments to pay or receive interest (e.g., an exchange of fixed rate payments for floating rate payments or an exchange of floating rate payments based on two different reference indices). By design, one of the reference indices is an inflation index, such as the Consumer Price Index.

Interest rate swaps involve the exchange by two parties of their respective commitments to pay or receive interest (e.g., an exchange of floating rate payments for fixed rate payments).

Options are the right, but not the obligation, to buy or sell a specified amount of securities or other assets on or before a fixed date at a predetermined price. The Portfolio may purchase and write put and call options on securities, securities indices, and foreign currencies. The Portfolio may purchase or write such options individually or in combination.

Total return swaps involve an exchange by two parties in which one party makes payments based on a set rate, either fixed or variable, while the other party makes payments based on the return of an underlying asset, which includes both the income it generates and any capital gains over the payment period. A fixed-income total return swap may be written on many different kinds of underlying reference assets, and may include different indices for various kinds of debt securities (e.g., U.S. investment grade bonds, high-yield bonds, or emerging market bonds).

39 | Janus Aspen Series

Other Investments, Strategies, and/or Techniques

Cash sweep program is an arrangement in which the Portfolio’s uninvested cash balance is used to purchase shares of affiliated or non-affiliated money market funds or cash management pooled investment vehicles that operate pursuant to the provisions of the Investment Company Act of 1940, as amended, that govern the operation of money market funds at the end of each day.

Diversification is a classification given to a portfolio under the Investment Company Act of 1940, as amended. Portfolios are classified as either diversified or nondiversified. To be classified as diversified under the Investment Company Act of 1940, as amended, a portfolio may not, with respect to 75% of its total assets, invest more than 5% of its total assets in any issuer and may not own more than 10% of the outstanding voting securities of an issuer. A portfolio that is classified as nondiversified under the Investment Company Act of 1940, as amended, on the other hand, has the flexibility to take larger positions in securities than a portfolio that is classified as diversified. However, because the appreciation or depreciation of a single security may have a greater impact on the net asset value of a portfolio which is classified as nondiversified, its share price can be expected to fluctuate more than a comparable portfolio which is classified as diversified.

Market capitalization is the most commonly used measure of the size and value of a company. It is computed by multiplying the current market price of a share of the company’s stock by the total number of its shares outstanding. Market capitalization is an important investment criterion for certain portfolios, while others do not emphasize investments in companies of any particular size.

Repatriation is the ability to move liquid financial assets from a foreign country to an investor’s country of origin.

Repurchase agreements involve the purchase of a security by the Portfolio and a simultaneous agreement by the seller (generally a bank or dealer) to repurchase the security from the Portfolio at a specified date or upon demand. This technique offers a method of earning income on idle cash.

Short sales in which the Portfolio may engage may be either “short sales against the box” or other short sales. Short sales against the box involve selling short a security that the Portfolio owns, or the Portfolio has the right to obtain the amount of the security sold short at a specified date in the future. The Portfolio may also enter into a short sale to hedge against anticipated declines in the market price of a security or to reduce portfolio volatility. If the value of a security sold short increases prior to the scheduled delivery date, the Portfolio loses the opportunity to participate in the gain.

When-issued, delayed delivery, and forward commitment transactions generally involve the purchase of a security with payment and delivery at some time in the future – i.e., beyond normal settlement. New issues of stocks and bonds, private placements, and U.S. Government securities may be sold in this manner.

40 | Janus Aspen Series

You can make inquiries and request other information, including a Statement of Additional Information, annual report, semiannual report, or Portfolio financial statements (as they become available), free of charge, by contacting your insurance company or plan sponsor, or by contacting a Janus Henderson representative at 1-877-335-2687. The Portfolio’s Statement of Additional Information, most recent annual and semiannual reports and Portfolio financial statements are also available, free of charge, at janushenderson.com/VIT. Additional information about the Portfolio’s investments is available in the Portfolio’s annual and semiannual reports and in Form N-CSR. In the Portfolio’s annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Portfolio’s performance during its last fiscal period. In Form N-CSR, you will find the Portfolio’s annual and semi-annual financial statements. Other information is also available from financial intermediaries that sell Shares of the Portfolio.

The Statement of Additional Information provides detailed information about the Portfolio and is incorporated into this Prospectus by reference. Reports and other information about the Portfolio are available on the Electronic Data Gathering Analysis and Retrieval (EDGAR) Database on the SEC’s website at http://www.sec.gov. You may obtain copies of this information, after paying a duplicating fee, by electronic request at the following e-mail address: publicinfo@sec.gov.

janushenderson.com/VIT

151 Detroit Street
Denver, CO 80206-4805
1-877-335-2687

The Trust’s Investment Company Act File No. is 811-7736.

This Prospectus describes Janus Henderson Enterprise Portfolio (the “Portfolio”), a series of Janus Aspen Series (the “Trust”). Janus Henderson Investors US LLC (the “Adviser”) serves as investment adviser to the Portfolio. The Portfolio currently offers two classes of shares. The Service Shares (the “Shares”) are offered by this Prospectus in connection with investment in and payments under variable annuity contracts and variable life insurance contracts (collectively, “variable insurance contracts”), as well as certain qualified retirement plans.

For the purpose of this Prospectus, any reference to the “Janus Henderson funds” is inclusive of all series of the Trust, collectively, unless otherwise noted in this Prospectus.

Portfolio summary

Janus Henderson Enterprise Portfolio

Ticker:

N/A

Service Shares

Investment Objective

Janus Henderson Enterprise Portfolio (“Enterprise Portfolio”) seeks long-term growth of capital.

Fees and Expenses of the Portfolio

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		0.64%
Distribution/Service (12b-1) Fees		0.25%
Other Expenses		0.08%
Total Annual Fund Operating Expenses		0.97%

EXAMPLE:

	1 Year	3 Years	5 Years	10 Years
Service Shares	$ 99	$ 309	$ 536	$ 1,190

Principal investment strategies

The Portfolio pursues its investment objective by investing primarily in common stocks selected for their growth potential, and normally invests at least 50% of its equity assets in medium-sized companies. The Portfolio considers medium-sized companies to be those whose market capitalization falls within the range of companies in the Russell Midcap® Growth Index. Market capitalization is a commonly used measure of the size and value of a company. The market capitalizations within the index will vary, but as of December 31, 2024, they ranged from approximately $343 million to $151.89 billion. The Portfolio may also invest in foreign securities.

Portfolio management applies a “bottom-up” approach in choosing investments. In other words, portfolio management looks at companies one at a time to determine if a company is an attractive investment opportunity and if it is consistent with the Portfolio’s investment policies. Attributes considered in the process of securities selection may include sustainable growth, return on invested capital, attractive valuation, strength of management, and competitive positioning. The Portfolio will generally consider selling a stock when, in portfolio management’s opinion, there is a change in the company’s or industry’s fundamentals, there is a deterioration in a company’s competitive positioning, or if a company reaches or exceeds its targeted

2 | Janus Henderson Enterprise Portfolio

value. The Portfolio will also consider selling a stock if a company’s market capitalization exceeds the top of the medium-sized company range.

Principal investment risks

The biggest risk is that the Portfolio’s returns will vary, and you could lose money. The Portfolio is designed for long-term investors seeking an equity portfolio, including common stocks. The principal risks associated with investing in the Portfolio are set forth below.

Mid-Sized Companies Risk. Investments in securities issued by mid-sized companies may involve greater risks than are customarily associated with larger, more established companies. For example, mid-sized companies may suffer more significant losses as a result of their narrow product lines, limited operating history, greater exposure to competitive threats, limited financial resources, limited trading markets, and the potential lack of management depth. Securities issued by mid-sized companies tend to be more volatile than securities issued by larger or more established companies and may underperform as compared to the securities of larger or more established companies. These holdings are also subject to wider price fluctuations and tend to be less liquid than stocks of larger or more established companies, which could have a significant adverse effect on the Portfolio’s returns, especially as market conditions change.

3 | Janus Henderson Enterprise Portfolio

the Portfolio’s holdings become more concentrated, the Portfolio is less able to spread risk and potentially reduce the risk of loss and volatility. As the Portfolio’s holdings change over time, the Portfolio’s exposure to a particular economic sector may become higher or lower.

•

Technology Sector Risk. In the technology sector, competitive pressures may have a significant effect on the performance of companies in which the Portfolio may invest. In addition, technology and technology-related companies often progress at an accelerated rate, and these companies may be subject to short product cycles and aggressive pricing, which may increase their volatility.

Foreign Exposure Risk. Foreign markets can be more volatile than the U.S. market. As a result, the Portfolio’s returns and net asset value may be affected by fluctuations in currency exchange rates or political or economic conditions in a particular country. In some foreign markets, there may not be protection against failure by other parties to complete transactions. It may not be possible for the Portfolio to repatriate capital, dividends, interest, and other income from a particular country or governmental entity. In addition, a market swing in one or more countries or regions where the Portfolio has invested a significant amount of its assets may have a greater effect on the Portfolio’s performance than it would in a more geographically diversified portfolio.

An investment in the Portfolio is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance information

4 | Janus Henderson Enterprise Portfolio

Annual Total Returns for Service Shares (calendar year-end)

Best Quarter:

2nd Quarter 2020

23.04%

Worst Quarter:

1st Quarter 2020

– 24.43%

Average Annual Total Returns (periods ended 12/31/24)
	1 Year	5 Years	10 Years
Enterprise Portfolio
Service Shares	15.32%	9.61%	12.12%
Russell 3000® Index (reflects no deduction for fees, expenses, or taxes)	23.81%	13.86%	12.55%
Russell Midcap® Growth Index (reflects no deduction for fees, expenses, or taxes)	22.10%	11.47%	11.54%

Effective February 25, 2025, the Portfolio changed its broad-based securities market index from the Russell Midcap Growth Index to the Russell 3000 Index due to regulatory requirements. The Portfolio retained the Russell Midcap Growth Index as a performance benchmark because the Russell Midcap Growth Index is more closely aligned with the Portfolio’s investment strategies and investment restrictions. The indices are described below.

•

The Russell 3000 Index measures the performance of the largest 3,000 U.S. companies.

•

The Russell Midcap Growth Index measures the performance of those Russell Midcap companies with higher price-to-book ratios and higher forecasted growth values. The stocks are also members of the Russell 1000® Growth Index.

Management

Investment Adviser: Janus Henderson Investors US LLC

Portfolio Management: Brian Demain, CFA, is Executive Vice President and Lead Portfolio Manager of the Portfolio, which he has managed or co-managed since November 2007. Cody Wheaton, CFA, is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since July 2016.

Purchase and sale of Portfolio shares

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Redemptions, like purchases, may be effected only through the separate accounts of participating insurance companies or through qualified retirement plans. Requests are duly processed at the net asset value next calculated after an order is received in good order by the Portfolio or its agents. Refer to the appropriate separate account prospectus or plan documents for details.

Tax information

5 | Janus Henderson Enterprise Portfolio

Additional information about the Portfolio

Fees and expenses

•

“Other Expenses”

•

Additional investment strategies and general portfolio policies

7 | Janus Aspen Series

Security Selection

The Portfolio pursues its investment objective by investing primarily in common stocks selected for their growth potential, and normally invests at least 50% of its equity assets in medium-sized companies, as determined by reference to the Russell Midcap Growth Index. Portfolio management applies a “bottom-up” approach in choosing investments. In other words, portfolio management looks at companies one at a time to determine if a company is an attractive investment opportunity and if it is consistent with the Portfolio’s investment policies. Attributes considered in the process of securities selection may include sustainable growth, return on invested capital, attractive valuation, strength of management, and competitive positioning. The Portfolio will generally consider selling a stock when, in portfolio management’s opinion, there is a change in the company’s or industry’s fundamentals, there is a deterioration in a company’s competitive positioning, or if a company reaches or exceeds its targeted value. The Portfolio will also consider selling a stock if a company’s market capitalization exceeds the top of the medium-sized company range.

Cash Position

Derivatives

Emerging Markets

ESG Integration

Foreign Securities

8 | Janus Aspen Series

without regard to any predetermined allocation among countries or geographic regions. However, certain factors, such as expected levels of inflation, government policies influencing business conditions, the outlook for currency relationships, and prospects for economic growth among countries, regions, or geographic areas, may warrant greater consideration in selecting foreign securities. The Portfolio may at times have significant foreign exposure, including exposure to emerging markets.

Illiquid Investments

Initial Public Offerings and Secondary Offerings

Leverage

Portfolio Turnover

In general, the Portfolio intends to purchase securities for long-term investment, although, to a limited extent, the Portfolio may purchase securities in anticipation of relatively short-term gains. Short-term transactions may also result from liquidity needs, securities having reached a price or yield objective, changes in interest rates or the credit standing of an issuer, or by reason of economic or other developments not foreseen at the time of the initial investment decision. The Portfolio may also sell one security and simultaneously purchase the same or a comparable security to take advantage of short-term differentials in bond yields or securities prices. Portfolio turnover is affected by market conditions, changes in the size of the Portfolio (including due to shareholder purchases and redemptions), the nature of the Portfolio’s investments, and the investment style of portfolio management. Changes are normally made in the Portfolio’s holdings whenever portfolio management believes such changes are desirable. Portfolio turnover rates are generally not a factor in making buy and sell decisions for the Portfolio.

REITs and Real Estate-Related Securities

9 | Janus Aspen Series

Securities Lending

Short Sales

The Portfolio may invest in short positions through short sales of stocks and structured products, and through derivatives that include swaps, uncovered written calls, and futures. The Portfolio may also engage in short sales “against the box” and options for hedging purposes. Short sales against the box involve selling short a security that the Portfolio owns, or the Portfolio has the right to obtain the amount of the security sold short at a specified date in the future. The Portfolio may also enter into a short sale to hedge against anticipated declines in the market price of a security or to reduce portfolio volatility.

10 | Janus Aspen Series

Special Situations

Other Types of Investments

•

debt securities (such as bonds, notes, sovereign debt, and debentures)

•

preferred stocks and securities convertible into common stocks or preferred stocks

•

indexed/structured securities (such as commercial and residential mortgage- and asset-backed securities)

•

securities purchased on a when-issued, delayed delivery, or forward commitment basis

•

equity and fixed-income securities issued in private placement transactions

Risks of the Portfolio

11 | Janus Aspen Series

that the Portfolio focuses its transactions with a limited number of counterparties, it will have greater exposure to the risks associated with one or more counterparties.

12 | Janus Aspen Series

•

Transaction Costs Risk. Costs of buying, selling, and holding foreign securities, including brokerage, tax, and custody costs, may be higher than those involved in domestic transactions.

13 | Janus Aspen Series

•

Liquidity Risk. The Portfolio may invest in securities or instruments that do not trade actively or in large volumes, and may make investments that are less liquid than other investments. Also, the Portfolio may make investments that may become less liquid in response to market developments or adverse investor perceptions. Investments that are illiquid or that trade in lower volumes may be more difficult to value. When there is no willing buyer and investments cannot be readily sold at the desired time or price, the Portfolio may have to accept a lower price or may not be able to sell the security or instrument at all. Investments in foreign securities, particularly those of issuers located in emerging market countries, tend to have greater exposure to liquidity risk than domestic securities. In unusual market conditions, even normally liquid securities may be affected by a degree of liquidity risk (i.e., if the number and capacity of traditional market participants is reduced). An inability to sell one or more portfolio positions can adversely affect the Portfolio’s value or prevent the Portfolio from being able to take advantage of other investment opportunities.

14 | Janus Aspen Series

types of securities than the types of securities in which the Portfolio invests. If the value of the Portfolio’s holdings decreases, the Portfolio’s net asset value will also decrease, which means if you sell your shares in the Portfolio you may lose money. Market risk may affect a single issuer, industry, economic sector, or the market as a whole.

•

15 | Janus Aspen Series

threats, limited financial resources, limited trading markets, and the potential lack of management depth. Securities issued by small- and mid-sized companies tend to be more volatile and somewhat more speculative than securities issued by larger or more established companies and may underperform as compared to the securities of larger or more established companies. These holdings are also subject to wider price fluctuations and tend to be less liquid than stocks of larger or more established companies, which could have a significant adverse effect on the Portfolio’s returns, especially as market conditions change.

Sovereign Debt Risk. The Portfolio may invest in U.S. and non-U.S. government debt securities (“sovereign debt”). Investments in sovereign debt, especially the debt of certain emerging market countries, can involve a high degree of risk, including the risk that the governmental entity that controls the repayment of sovereign debt may not be willing or able to repay the principal and/or to pay the interest on its sovereign debt in a timely manner. A sovereign debtor’s willingness or ability to satisfy its debt obligation may be affected by various factors, including its cash flow situation, the extent of its foreign currency reserves, the availability of foreign exchange when a payment is due, the relative size of its debt position in relation to its economy as a whole, the sovereign debtor’s policy toward international lenders, and local political constraints to which the governmental entity may be subject. Sovereign debtors may also be dependent on expected disbursements from foreign governments, multilateral agencies, and other entities. The failure of a sovereign debtor to implement economic reforms, achieve specified levels of economic performance, or repay principal or interest when due may result in the cancellation of third party commitments to lend funds to the sovereign debtor, which may further impair such debtor’s ability or willingness to timely service its debts. The Portfolio may be requested to participate in the rescheduling of such sovereign debt and to extend further loans to governmental entities, which may adversely affect the Portfolio’s holdings. In the event of default, there may be limited or no legal remedies for collecting sovereign debt and there may be no bankruptcy proceedings through which the Portfolio may collect all or part of the sovereign debt that a governmental entity has not repaid. In addition, to the extent the Portfolio invests in non-U.S. sovereign debt, it may be subject to currency risk.

16 | Janus Aspen Series

Management of the Portfolio

Investment adviser

The Trust and the Adviser have received an exemptive order from the Securities and Exchange Commission (the “SEC”) that permits the Adviser, subject to the approval of the Trustees, to appoint or replace certain subadvisers to manage all or a portion of the Portfolio’s assets and enter into, amend, or terminate a subadvisory agreement with certain subadvisers without obtaining shareholder approval (a “manager-of-managers structure”). The manager-of-managers structure applies to subadvisers that are not affiliated with the Trust or the Adviser (“non-affiliated subadvisers”), as well as any subadviser that is an indirect or direct “wholly-owned subsidiary” (as such term is defined by the Investment Company Act of 1940, as amended) of the Adviser or of another company that, indirectly or directly, wholly owns the Adviser (collectively, “wholly-owned subadvisers”).

Management expenses

17 | Janus Aspen Series

Portfolio Name	Average Daily Net Assets of the Portfolio	Contractual Investment Advisory Fee (%) (annual rate)	Actual Compensation Rate Paid to Adviser (%) (for the fiscal year ended December 31, 2024)
Enterprise Portfolio	All Asset Levels	0.64	0.64

Portfolio management

Enterprise Portfolio

Co-Portfolio Managers Brian Demain and Cody Wheaton are responsible for the day-to-day management of the Portfolio. Mr. Demain, as Lead Portfolio Manager, has the authority to exercise final decision-making on the overall portfolio.

Brian Demain, CFA, is Executive Vice President and Lead Portfolio Manager of Enterprise Portfolio, which he has managed or co-managed since November 2007. Mr. Demain is also Portfolio Manager of other Janus Henderson accounts. He holds a Bachelor of Arts degree (summa cum laude) in Economics from Princeton University, where he was a recipient of the Daniel L. Rubinfeld ’67 Prize in Empirical Economics for his senior thesis. Mr. Demain holds the Chartered Financial Analyst designation.

Cody Wheaton, CFA, is Executive Vice President and Co-Portfolio Manager of Enterprise Portfolio, which he has co-managed since July 2016. Mr. Wheaton is also Portfolio Manager of other Janus Henderson accounts and performs duties as an analyst. He holds Bachelor of Arts degrees in Economics and Government from Dartmouth College. Mr. Wheaton holds the Chartered Financial Analyst designation.

Conflicts of Interest

18 | Janus Aspen Series

Other information

Classes of Shares

Closed Portfolio Policies

Liquidation/Reorganization of a Portfolio

DISTRIBUTION OF THE Portfolio

19 | Janus Aspen Series

Distributions and taxes

Distributions

Distribution Schedule

How Distributions Affect the Portfolio’s NAV

TAXES

Taxes on Distributions

Taxation of the Portfolio

20 | Janus Aspen Series

Shareholder’s guide

Pricing of portfolio shares

21 | Janus Aspen Series

Distribution, servicing, and administrative fees

Distribution and Shareholder Servicing Plan

Administrative Fees

Payments to financial intermediaries by the Adviser or its affiliates

22 | Janus Aspen Series

Purchases

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Refer to the prospectus of the appropriate insurance company separate account or your plan documents for information on how to invest in the Shares of the Portfolio. Under certain circumstances, the Portfolio may permit an in-kind purchase of Shares. Participating insurance companies and certain other designated organizations are authorized to receive purchase orders on the Portfolio’s behalf. As discussed under “Payments to Financial Intermediaries by the Adviser or its Affiliates,” the Adviser and its affiliates make payments to selected insurance companies, qualified plan service providers, or their affiliates, or other financial intermediaries that were instrumental in the acquisition or retention of accounts for the Portfolio or that provide services in connection with investments in the Portfolio. You should consider such arrangements when evaluating any recommendation of the Portfolio.

23 | Janus Aspen Series

Potential Conflicts

Redemptions

Large Shareholder Redemptions

24 | Janus Aspen Series

Redemptions In-Kind

Excessive trading

Excessive and Short-Term Trading Policies and Procedures

The Janus Henderson funds attempt to deter excessive trading through at least the following methods:

•

fair valuation of securities as described under “Pricing of Portfolio Shares”; and

•

trade monitoring.

The Portfolio’s Trustees may approve from time to time a redemption fee to be imposed by any Janus Henderson fund, subject to 60 days’ notice to shareholders of that fund.

25 | Janus Aspen Series

particular intermediaries may vary depending on the systems’ capabilities, applicable contractual and legal restrictions, and cooperation of those intermediaries.

The Portfolio’s policies and procedures regarding excessive trading may be modified at any time by the Portfolio’s Trustees.

Excessive Trading Risks

Availability of Portfolio Holdings Information

•

26 | Janus Aspen Series

•

Top Holdings. The Portfolio’s top portfolio holdings, in order of position size and as a percentage of the Portfolio’s total portfolio, are available monthly with a 15-day lag.

•

Other Information. The Portfolio may occasionally provide security breakdowns (e.g., industry, sector, regional, market capitalization, and asset allocation) and specific portfolio level performance attribution information and statistics monthly with a 15-day lag. Top/bottom equity securities ranked by performance attribution, including the percentage attribution to Portfolio performance, average Portfolio weighting, and other relevant data points, may be provided monthly with a 15-day lag.

Shareholder communications

27 | Janus Aspen Series

Financial highlights

Enterprise Portfolio – Service Shares

	Years ended December 31
	2024	2023	2022	2021	2020
Net Asset Value, Beginning of Period	$68.37	$62.78	$92.49	$87.46	$79.93
Income/(Loss) from Investment Operations:
Net investment income/(loss)(1)	0.07	0.16	0.02	(0.03)	—(2)
Net realized and unrealized gain/(loss)	10.05	10.64	(15.57)	13.87	13.45
Total from Investment Operations	10.12	10.80	(15.55)	13.84	13.45
Less Dividends and Distributions:
Dividends (from net investment income)	(0.47)	(0.06)	(0.06)	(0.23)	—
Distributions (from capital gains)	(3.30)	(5.15)	(14.10)	(8.58)	(5.92)
Total Dividends and Distributions	(3.77)	(5.21)	(14.16)	(8.81)	(5.92)
Net Asset Value, End of Period	$74.72	$68.37	$62.78	$92.49	$87.46
Total Return*	15.32%	17.78%	(16.15)%	16.54%	19.18%
Net Assets, End of Period (in thousands)	$1,072,653	$916,508	$807,716	$1,039,696	$922,221
Ratios to Average Net Assets
Ratio of Gross Expenses	0.97%	0.97%	0.96%	0.96%	0.97%
Ratio of Net Expenses (After Waivers and Expense Offsets)	0.97%	0.97%	0.96%	0.96%	0.97%
Ratio of Net Investment Income/(Loss)	0.09%	0.25%	0.03%	(0.03)%	0.00%(3)
Portfolio Turnover Rate	14%	13%	15%	17%	16%

*	Total return includes adjustments in accordance with generally accepted accounting principles required at the year or period end and are not annualized for periods of less than one full year. Total return does not include fees, charges, or expenses imposed by the variable annuity and life insurance contracts for which Janus Aspen Series serves as an underlying investment vehicle.
(1)	Per share amounts are calculated based on average shares outstanding during the year or period.
(2)	Less than $0.005 on a per share basis.
(3)	Less than 0.005%.

28 | Janus Aspen Series

Glossary of investment terms

Equity and Debt Securities

Convertible securities are preferred stocks or bonds that pay a fixed dividend or interest payment and are convertible into common stock at a specified price or conversion ratio.

Rule 144A securities are securities that are not registered for sale to the general public under the Securities Act of 1933, as amended, but that may be resold to certain institutional investors.

29 | Janus Aspen Series

Futures, Options, and Other Derivatives

Other Investments, Strategies, and/or Techniques

Repatriation is the ability to move liquid financial assets from a foreign country to an investor’s country of origin.

30 | Janus Aspen Series

janushenderson.com/VIT

151 Detroit Street
Denver, CO 80206-4805
1-877-335-2687

The Trust’s Investment Company Act File No. is 811-7736.

This Prospectus describes Janus Henderson Flexible Bond Portfolio (the “Portfolio”), a series of Janus Aspen Series (the “Trust”). Janus Henderson Investors US LLC (the “Adviser”) serves as investment adviser to the Portfolio. The Portfolio currently offers two classes of shares. The Service Shares (the “Shares”) are offered by this Prospectus in connection with investment in and payments under variable annuity contracts and variable life insurance contracts (collectively, “variable insurance contracts”), as well as certain qualified retirement plans.

For the purpose of this Prospectus, any reference to the “Janus Henderson funds” is inclusive of all series of the Trust, collectively, unless otherwise noted in this Prospectus.

Portfolio summary

Janus Henderson Flexible Bond Portfolio

Ticker:

N/A

Service Shares

Investment Objective

Janus Henderson Flexible Bond Portfolio (“Flexible Bond Portfolio”) seeks to obtain maximum total return, consistent with preservation of capital.

Fees and Expenses of the Portfolio

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		0.50%
Distribution/Service (12b-1) Fees		0.25%
Other Expenses		0.13%
Total Annual Fund Operating Expenses		0.88%
Fee Waiver and/or Expense Reimbursement(1)		0.06%
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement(1)		0.82%

(1)

The Adviser has contractually agreed to waive its investment advisory fee and/or reimburse Portfolio expenses to the extent that the Portfolio’s total annual fund operating expenses (excluding fees payable pursuant to a Rule 12b-1 plan, shareholder servicing fees, out-of-pocket transfer agency/shareholder servicing costs, acquired fund fees and expenses, interest, dividends, taxes, brokerage commissions, and extraordinary expenses) exceed 0.52%. In addition, the Adviser has contractually agreed to waive and/or reimburse a portion of the Portfolio’s management fee in an amount equal to the management fee it earns as an investment adviser to any affiliated exchange-traded funds (“ETFs”) in which the Portfolio invests, less certain operating expenses. The contractual waivers will remain in effect for at least a one-year period commencing on April 30, 2025. These contractual waivers may be terminated or modified only at the discretion of the Board of Trustees.

EXAMPLE:

The Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated, reinvest all dividends and distributions, and then redeem all of your Shares at the end of each period. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses are equal to the Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement for the first year and the Total Annual Fund Operating Expenses thereafter. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years	5 Years	10 Years
Service Shares	$ 84	$ 275	$ 482	$ 1,079

Principal investment strategies

The Portfolio pursues its investment objective by primarily investing, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in bonds. Bonds include, but are not limited to, government notes and bonds, corporate bonds, commercial and residential mortgage-backed securities, asset-backed securities, credit risk transfer securities (“CRTs”), and money market instruments. The Portfolio may invest in fixed and floating rate obligations with

2 | Janus Henderson Flexible Bond Portfolio

varying durations. The Portfolio’s average portfolio duration typically ranges between three and seven years. As of December 31, 2024, the Portfolio’s average portfolio duration was 6.54 years.

The Portfolio will invest at least 65% of its net assets in investment grade debt securities. The Portfolio will limit its investment in high-yield bonds (also known as “junk” bonds) to 35% or less of its net assets. The Portfolio generates total return from a combination of current income and capital appreciation, but income is usually the dominant portion. The Portfolio may enter into “to be announced” or “TBA” commitments when purchasing mortgage-backed securities or other securities. The Portfolio also invests in securities that have contractual restrictions that prohibit or limit their public resale, which may include Rule 144A securities. The Portfolio may also invest in foreign securities. Due to the nature of the securities in which the Portfolio invests, it may have relatively high portfolio turnover compared to other portfolios.

Additionally, the Portfolio may invest its assets in derivatives. Derivative instruments have a value derived from, or directly linked to, an underlying asset, such as fixed-income securities, commodities, currencies, interest rates, or market indices. In particular, the Portfolio may use interest rate swaps and futures, including Treasury bond futures, to manage interest rate risk, yield curve positioning, and country exposure. The Portfolio may also use index credit default swaps for hedging purposes (to offset risks associated with an investment exposure, or market conditions), to increase or decrease the Portfolio’s exposure to a particular market, to manage or adjust the risk profile of the Portfolio relative to its benchmark index, and to earn income, enhance returns, or preserve capital. The Portfolio’s exposure to derivatives will vary. For purposes of meeting its 80% investment policy, the Portfolio may include derivatives that have characteristics similar to the securities in which the Portfolio may directly invest. The Portfolio may take short positions on derivatives instruments.

Portfolio management’s investment process is research-driven, incorporating “top-down” and “bottom-up” factors to identify and manage exposure to risks across sectors, industries, and individual investments. Portfolio management evaluates expected risk-adjusted returns on a portfolio and position level by analyzing fundamentals, valuations, and market technical indicators. This research encompasses both traditional fundamental analysis and data driven quantitative models and signals from such models.

Principal investment risks

The biggest risk is that the Portfolio’s returns and yields will vary, and you could lose money. The principal risks associated with investing in the Portfolio are set forth below.

Fixed-Income Securities Risk. Fixed-income securities are generally subject to the following risks:

•

3 | Janus Henderson Flexible Bond Portfolio

•

Sovereign Debt Risk. Investments in U.S. and non-U.S. government debt securities (“sovereign debt”) can involve a high degree of risk, including the risk that the governmental entity that controls the repayment of sovereign debt may not be willing or able to repay the principal and/or to pay the interest on its sovereign debt in a timely manner. A sovereign debtor’s willingness or ability to satisfy its debt obligation may be affected by various factors including, but not limited to, its cash flow situation, the extent of its foreign currency reserves, the availability of foreign exchange when a payment is due, and the relative size of its debt position in relation to its economy as a whole. In the event of default, there may be limited or no legal remedies for collecting sovereign debt and there may be no bankruptcy proceedings through which the Portfolio may collect all or part of the sovereign debt that a governmental entity has not repaid. In addition, to the extent the Portfolio invests in non-U.S. sovereign debt, it may be subject to currency risk.

Credit Risk Transfer Securities Risk. CRTs are unguaranteed and unsecured fixed or floating rate general obligations that are commonly issued by government sponsored enterprises. CRTs are not directly linked to or backed by the underlying mortgage loans, so investors such as the Portfolio have no direct recourse to the underlying mortgage loans in the event of a default. The risks associated with CRTs are different from the risks associated with investments in mortgage-backed securities issued by government sponsored enterprises or private issuers because some or all of the mortgage default or credit risk associated with the underlying mortgage loans is transferred to investors. These risks are in addition to the risks described under “Fixed-Income Securities Risk.”

4 | Janus Henderson Flexible Bond Portfolio

Portfolio Turnover Risk. Increased portfolio turnover may result in higher costs, which may have a negative effect on the Portfolio’s performance.

5 | Janus Henderson Flexible Bond Portfolio

An investment in the Portfolio is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance information

The following information provides some indication of the risks of investing in the Portfolio by showing how the Portfolio’s performance has varied over time. The bar chart depicts the change in performance from year to year during the periods indicated. Total return figures include the effect of the Portfolio’s expenses, but do not include charges or expenses attributable to any insurance product, which would lower the performance illustrated. The table compares the average annual returns for the Service Shares of the Portfolio for the periods indicated to a broad-based securities market index. All figures assume reinvestment of dividends and distributions. For certain periods, the Portfolio’s performance reflects the effect of expense waivers. Without the effect of these expense waivers, the performance shown would have been lower.

Annual Total Returns for Service Shares (calendar year-end)

Best Quarter:

4th Quarter 2023

7.08%

Worst Quarter:

1st Quarter 2022

– 6.25%

Average Annual Total Returns (periods ended 12/31/24)
	1 Year	5 Years	10 Years
Flexible Bond Portfolio
Service Shares	1.63%	0.09%	1.35%
Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses, or taxes)	1.25%	– 0.33%	1.35%

The Portfolio’s broad-based benchmark index is the Bloomberg U.S. Aggregate Bond Index. The index is described below.

•

The Bloomberg U.S. Aggregate Bond Index is made up of U.S. dollar-denominated, fixed-rate taxable bonds, including securities that are of investment grade quality or better.

Management

Investment Adviser: Janus Henderson Investors US LLC

Portfolio Management: Michael Keough is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since December 2015. John Lloyd is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since June 2024. Greg Wilensky, CFA, is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since February 2020.

Purchase and sale of Portfolio shares

6 | Janus Henderson Flexible Bond Portfolio

separate accounts of participating insurance companies or through qualified retirement plans. Requests are duly processed at the net asset value next calculated after an order is received in good order by the Portfolio or its agents. Refer to the appropriate separate account prospectus or plan documents for details.

Tax information

Payments to Insurers, Broker-Dealers, and other financial intermediaries

7 | Janus Henderson Flexible Bond Portfolio

Additional information about the Portfolio

Fees and expenses

•

“Other Expenses”

•

Additional investment strategies and general portfolio policies

The Portfolio’s Board of Trustees (“Trustees”) may change the Portfolio’s investment objective or non-fundamental principal investment strategies without a shareholder vote. The Portfolio will notify you in writing at least 60 days before making any such change it considers material. In addition, the Portfolio will provide shareholders with at least 60 days’ notice prior to changing the 80% investment policy. If there is a material change to the Portfolio’s investment objective or principal investment strategies, you should consider whether the Portfolio remains an appropriate investment for you. There is no guarantee that the Portfolio will achieve its investment objective.

8 | Janus Aspen Series

not be required to dispose of any securities. The “Glossary of Investment Terms” includes descriptions of investment terms used throughout the Prospectus.

Security Selection

The Portfolio pursues its investment objective by primarily investing, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in bonds. Portfolio management’s investment process is research-driven, incorporating “top-down” and “bottom-up” factors to identify and manage exposure to risks across sectors, industries, and individual investments. Portfolio management evaluates expected risk-adjusted returns on a portfolio and position level by analyzing fundamentals, valuations, and market technical indicators. This research encompasses both traditional fundamental analysis and data driven quantitative models and signals from such models.

Portfolio management may consider selling a holding if, among other things, the security reaches portfolio management’s price target, if the company has a deterioration of fundamentals such as failing to meet key operating benchmarks, or if portfolio management finds a better investment opportunity. Portfolio management may also consider selling a Portfolio holding to meet redemptions.

Cash Position

Derivatives

Emerging Markets

ESG Integration

9 | Janus Aspen Series

Exchange-Traded Funds

Foreign Securities

High-Yield Bonds

Illiquid Investments

Inflation-Linked Securities

Leverage

10 | Janus Aspen Series

Loans

Mortgage- and Asset-Backed Securities

Portfolio Turnover

Portfolio turnover rates are generally not a factor in making buy and sell decisions for the Portfolio. Changes may be made to the Portfolio’s holdings, consistent with the Portfolio’s investment objective and policies, when portfolio management believes such changes are in the best interests of the Portfolio and its shareholders. Short-term transactions may result from the purchase of a security in anticipation of relatively short-term gains, liquidity needs, securities having reached a price or yield objective, changes in interest rates or the credit standing of an issuer, or by reason of economic or other developments not foreseen at the time of the initial investment decision. The Portfolio may also sell one security and simultaneously purchase the same or a comparable security to take advantage of short-term differentials in bond yields or securities prices. Portfolio turnover is affected by market conditions, changes in the size of the Portfolio (including due to shareholder purchases and redemptions), the nature of the Portfolio’s investments, and the investment style of portfolio management. Changes are

11 | Janus Aspen Series

normally made in the Portfolio’s holdings whenever portfolio management believes such changes are desirable. Due to the nature of the securities in which the Portfolio invests, it may have relatively high portfolio turnover compared to other portfolios.

REITs and Real Estate-Related Securities

Securities Lending

Short Sales

12 | Janus Aspen Series

the security borrowed by purchasing the security at the market price at the time of replacement. A short sale is subject to the risk that if the price of the security sold short increases in value, the Portfolio will incur a loss because it will have to replace the security sold short by purchasing it at a higher price. In addition, the Portfolio may not always be able to close out a short position at a particular time or at an acceptable price. A lender may request, or market conditions may dictate, that the borrowed securities be returned to the lender on short notice, and the Portfolio may have to buy the borrowed securities at an unfavorable price. If this occurs at a time when other short sellers of the same security also want to close out their positions, a “short squeeze” can occur, which means that the demand is greater than the supply for the security sold short. If a short squeeze occurs, it is more likely that the Portfolio will have to cover its short sale at an unfavorable price and potentially reduce or eliminate any gain, or cause a loss, as a result of the short sale. Because there is no upper limit to the price a borrowed security may reach prior to closing a short position, the Portfolio’s losses are potentially unlimited in a short sale transaction. The Portfolio’s gains and losses will also be decreased or increased, as the case may be, by the amount of any dividends, interest, or expenses, including transaction costs and borrowing fees, the Portfolio may be required to pay in connection with a short sale. Such payments may result in the Portfolio having higher expenses than a portfolio that does not engage in short sales and may negatively affect the Portfolio’s performance.

Special Situations

Swap Agreements

Index Credit Default Swaps. The Portfolio may invest in index credit default swaps (“CDX”). CDX are swaps on an index of credit default swaps. CDX allow an investor to manage credit risk or take a position on a basket of credit entities (such as credit default swaps or a commercial mortgage-backed index) in a more efficient manner than transacting in a single-name credit default swap. If a credit event occurs in one of the underlying companies, the protection is paid out via the delivery of the defaulted bond by the buyer of protection in return for a payment of notional value of the defaulted bond by the seller of protection or it may be settled through a cash settlement between the two parties. The underlying company is then removed from the index. New series of CDX are issued on a regular basis.

13 | Janus Aspen Series

TBA Commitments

U.S. Government Securities

Other Types of Investments

•

equity securities (such as stocks or any other security representing an ownership interest)

•

preferred stocks and securities convertible into common stocks or preferred stocks

•

pass-through securities including mortgage dollar rolls

•

collateralized debt obligations, collateralized mortgage obligations, and other similarly structured securities

•

pay-in-kind, and step coupon securities

•

securities purchased on a when-issued, delayed delivery, or forward commitment basis

•

equity and fixed-income securities issued in private placement transactions

Risks of the Portfolio

The value of your investment will vary over time, sometimes significantly, and you may lose money by investing in the Portfolio. The Portfolio invests substantially all of its assets in fixed-income securities or income-generating securities and, to varying degrees, derivatives. The following information is intended to help you better understand some of the risks of investing in the Portfolio, including those risks that are summarized in the Portfolio Summary section. This information also includes descriptions of other risks the Portfolio may be subject to as a result of additional investment strategies and general policies that may apply to the Portfolio. The impact of the following risks on the Portfolio may vary depending on the Portfolio’s investments. The greater the Portfolio’s investment in a particular security, the greater the Portfolio’s exposure to the risks associated with that security. Before investing in the Portfolio, you should consider carefully the risks that you assume when investing in the Portfolio.

14 | Janus Aspen Series

Collateralized Loan Obligation Risk. The risks of investing in a collateralized loan obligation (“CLO”) can be generally summarized as a combination of economic risks of the underlying loans and the risks associated with the CLO structure governing the priority of payments. The degree of such risk will generally correspond to the specific tranche in which the Portfolio is invested. Higher rated tranches (such as AAA rated tranches) do not constitute a guarantee and in stressed market environments it is possible that these CLO tranches could experience losses due to actual defaults, increased sensitivity to defaults due to collateral default and significant losses experienced by subordinated/equity tranches, market anticipation of defaults, as well as negative market sentiment with respect to CLO securities as an asset class. Portfolio management may not be able to accurately predict how specific CLOs or the portfolio of underlying loans for such CLOs will react to changes or stresses in the market, including changes in interest rates. The most common risks associated with investing in CLOs are interest rate risk, credit risk, liquidity risk, prepayment risk, and the risk of default of the underlying asset, among others.

Collateralized Mortgage Obligation Risk. Collateralized mortgage obligations (“CMOs”) are a type of mortgage-backed security. CMOs are created by dividing the principal and interest payments collected on a pool of mortgages into several revenue streams (tranches) with different priority rights to portions of the underlying mortgage payments. Certain CMO tranches may represent a right to receive interest only (“IOs”), principal only (“POs”) or an amount that remains after floating-rate tranches are paid (an inverse floater). These securities are frequently referred to as “mortgage derivatives” and may be extremely sensitive to changes in interest rates. Interest rates on inverse floaters, for example, vary inversely with a short-term floating rate (which may be reset periodically). Interest rates on inverse floaters will decrease when short-term rates increase, and will increase when short-term rates decrease. These securities have the effect of providing a degree of investment leverage. In response to changes in market interest rates or other market conditions, the value of an inverse floater may increase or decrease at a multiple of the increase or decrease in the value of the underlying securities. If the Portfolio invests in CMO tranches (including CMO tranches issued by government agencies) and interest rates move in a manner not anticipated by the Adviser, it is possible that the Portfolio could lose all or substantially all of its investment.

Many fixed-income securities receive credit ratings from services such as Standard & Poor’s, Fitch, and Moody’s. These services assign ratings to securities by assessing the likelihood of issuer default. The lower a bond issue is rated by an agency, the more credit risk it is considered to represent. Lower rated instruments and securities generally pay interest at a higher rate to compensate for the associated greater risk. Interest rates can fluctuate in response to economic or market conditions, which can result in a fluctuation in the price of a security and impact the Portfolio’s return and yield. If a security has not received a rating, the Portfolio must rely upon the Adviser’s credit assessment, which if incorrect can also impact the Portfolio’s returns and yield. Please refer to the “Explanation of Rating Categories” section of the SAI for a description of bond rating categories.

15 | Janus Aspen Series

backed by the underlying mortgage loans, so investors such as the Portfolio have no direct recourse to the underlying mortgage loans in the event of a default. The risks associated with CRTs are different from the risks associated with investments in mortgage-backed securities issued by government sponsored enterprises or private issuers because some or all of the mortgage default or credit risk associated with the underlying mortgage loans is transferred to investors. These risks are in addition to the risks described under “Fixed-Income Securities Risk.”

•

Futures and Swaps Related to Interest Rate Risk. The Portfolio’s investments in interest rate futures, swaps, or futures on interest rate sensitive securities entail the risk that portfolio management’s prediction of the direction of interest rates is wrong, and the Portfolio could incur a loss. In addition, due to the possibility of price distortions in the interest rate futures or swaps markets, or an imperfect correlation between the underlying instrument and the interest rate portfolio management is seeking to hedge, a correct forecast of general interest rate trends by portfolio management may not result in the successful use of futures and swaps related to interest rates.

•

16 | Janus Aspen Series

the Portfolio’s performance. The Portfolio may be subject to emerging markets risk to the extent that it invests in securities of issuers or companies which are not considered to be from emerging markets, but which have customers, products, or transactions associated with emerging markets.

Fixed-Income Securities Risk. The Portfolio invests in a variety of fixed-income securities. Typically, the values of fixed-income securities change inversely with prevailing interest rates. Therefore, a fundamental risk of fixed-income securities is interest rate risk, which is the risk that the value of such securities will generally decline as prevailing interest rates rise, which may cause the Portfolio’s net asset value to likewise decrease. How specific fixed-income securities may react to changes in interest rates will depend on the specific characteristics of each security. For example, while securities with longer maturities and durations tend to produce higher yields, they also tend to be more sensitive to changes in prevailing interest rates and are therefore more volatile than shorter-term securities and are subject to greater market fluctuations as a result of changes in interest rates. However, calculations of maturity and duration may be based on estimates and may not reliably predict a security’s price sensitivity to changes in interest rates. In addition, different interest rate measures (such as short- and long-term interest rates and U.S. and non-U.S. interest rates), or interest rates on different types of securities or securities of different issuers, may not necessarily change in the same amount or in the same direction. Investments in fixed-income securities with very low or negative interest rates may diminish the Portfolio’s yield and performance.

17 | Janus Aspen Series

directly in foreign markets, including emerging markets. Additional risks may be present with respect to investments in securities of issuers or companies that are economically tied to different countries throughout the world. An issuer is deemed to be economically tied to a country or countries if one or more of the following tests are met: (i) the issuer is organized in, or its primary business office or principal trading market of its equity is located in, the country; (ii) a majority of the issuer’s revenues are derived from one or more countries; or (iii) a majority of the issuer’s assets are located in one or more countries. Investments in foreign securities, including securities of foreign and emerging market governments, may involve greater risks than investing in domestic securities because the Portfolio’s performance may depend on factors other than the performance of a particular company. These factors include:

•

Transaction Costs Risk. Costs of buying, selling, and holding foreign securities, including brokerage, tax, and custody costs, may be higher than those involved in domestic transactions.

18 | Janus Aspen Series

Please refer to the “Explanation of Rating Categories” section of the SAI for a description of bond rating categories.

19 | Janus Aspen Series

Loan Risk. The Portfolio may invest in various commercial loans. The risks of such investments vary, depending on the type of loans underlying the investments, as described below.

•

20 | Janus Aspen Series

•

Money Market Fund Investment Risk. The Portfolio may have cash balances that have not been invested in portfolio securities, which may be used to purchase shares of affiliated or non-affiliated money market funds, or cash management pooled investment vehicles that operate as money market funds, as part of a cash sweep program. By investing in a money market fund, the Portfolio will be exposed to the investment risks of the money market fund in direct proportion to such investment. The money market fund may not achieve its investment objective and the Portfolio may lose money. To the extent the Portfolio transacts in instruments such as derivatives, the Portfolio may hold investments, which may be significant, in money market fund shares to cover its obligations resulting from the Portfolio’s investments in derivatives. An investment in a money market fund is not a bank deposit and is not insured or guaranteed by any bank, the Federal Deposit Insurance Corporation or any other government agency. There can be no assurance that a money market fund will maintain a $1.00 per share net asset value at all times. Factors that could adversely affect the value of a money market fund’s shares include, among other things, a sharp rise in interest rates, an illiquid market for the securities held by the money market fund, a high volume of redemption activity in a fund’s shares, and a credit event or credit rating downgrade affecting one or more of the issuers of securities held by the money market fund. In addition, the failure of even an unrelated money market fund to maintain a stable net asset value could create a widespread risk of increased redemption pressures on all money market funds, potentially jeopardizing the stability of their net asset values. Certain money market funds have in the past failed to maintain stable net asset values, and there can be no assurance that such failures and resulting redemption pressures will not impact money market funds in the future.

21 | Janus Aspen Series

In addition to the fees and expenses that the Portfolio directly bears, the Portfolio indirectly bears the fees and expenses of any money market fund in which it invests.

22 | Janus Aspen Series

heavy cash flow dependency to allow them to make distributions to their shareholders. The prices of equity REITs are affected by changes in the value of the underlying property owned by the REITs, changes in capital markets and interest rates, management skill in running a REIT, and the creditworthiness of the REIT. The prices of mortgage REITs are affected by the quality of any credit they extend, the creditworthiness of the mortgages they hold, as well as by the value of the property that secures the mortgages. In addition, mortgage REITs (similar to direct investments in mortgage-backed securities) are subject to prepayment risk. Equity REITs and mortgage REITs are subject to heavy cash flow dependency, defaults by borrowers, and self-liquidation. There is also the risk that borrowers under mortgages held by a REIT or lessees of a property that a REIT owns may be unable to meet their obligations to the REIT. In the event of a default by a borrower or lessee, the REIT may incur substantial costs associated with protecting its investments. While equity REITs and mortgage REITs may provide exposure to a large number of properties, such properties may be concentrated in a particular industry, region, or housing type, making such investments more vulnerable to unfavorable developments to economic or market events. Certain “special purpose” REITs in which the Portfolio may invest focus their assets in specific real property sectors, such as hotels, shopping malls, nursing homes, or warehouses, and are therefore subject to the specific risks associated with adverse developments in these sectors. The Portfolio’s shareholders will indirectly bear their proportionate share of the REIT’s expenses, in addition to their proportionate share of the Portfolio’s expenses. The value of investments in REOCs will generally be affected by the same factors that adversely affect REIT investments; however, REOCs may also be adversely affected by income streams derived from businesses other than real estate ownership.

Zero-Coupon, Step-Coupon, and Pay-in-Kind Securities Risk. These securities are debt obligations that do not make regular cash interest payments. Zero-coupon and step-coupon securities are sold at a discount from their face value. Zero-coupon securities do not pay interest until maturity. Step-coupon securities pay coupon interest that increases or decreases over the

23 | Janus Aspen Series

Management of the Portfolio

Investment adviser

Management expenses

The following table reflects the Portfolio’s contractual investment advisory fee rate (expressed as an annual rate), as well as the actual compensation rate paid by the Portfolio to the Adviser after any applicable fee waivers and/or expense reimbursements. The rate shown is a fixed rate based on the Portfolio’s average daily net assets.

25 | Janus Aspen Series

Portfolio Name	Average Daily Net Assets of the Portfolio	Contractual Investment Advisory Fee (%) (annual rate)	Actual Compensation Rate Paid to Adviser (%) (for the fiscal year ended December 31, 2024)
Flexible Bond Portfolio	First $300 Million	0.55	0.45
	Over $300 Million	0.45

Expense Limitation

The Adviser has contractually agreed to waive the advisory fee payable by the Portfolio or reimburse expenses in an amount equal to the amount, if any, that the Portfolio’s total annual fund operating expenses, including the investment advisory fee, but excluding fees payable pursuant to a Rule 12b-1 plan, shareholder servicing fees, out-of-pocket transfer agency/shareholder servicing costs, acquired fund fees and expenses, interest, dividends, taxes, brokerage commissions, and extraordinary expenses, exceed the annual rate shown below. Mortality risk, expense risk, and other charges imposed by participating insurance companies are also excluded from the expense limitation noted.

The Adviser has also contractually agreed to waive and/or reimburse a portion of the Portfolio’s management fee in an amount equal to the management fee it earns as an investment adviser to any affiliated ETFs in which the Portfolio invests. Pursuant to this agreement, the waiver amount is equal to the amount of the Portfolio’s assets invested in the affiliated ETFs, multiplied by an amount equal to the current daily unitary management fee of the affiliated ETF, less certain asset-based operating fees and expenses incurred on a per-fund basis and paid by the Adviser with respect to the affiliated ETFs (including, but not limited to custody, sub-administration, transfer agency, legal, and audit fees).

These contractual waivers may be modified or terminated only at the discretion of the Board of Trustees. For information about how the expense limit affects the total expenses of the Portfolio, if applicable, see the “Fees and Expenses of the Portfolio” table in the Portfolio Summary of the Prospectus. The Adviser has agreed to continue each waiver for at least a one-year period commencing on April 30, 2025.

Portfolio Name	Expense Limit Percentage (%)
Flexible Bond Portfolio	0.52

Portfolio management

Flexible Bond Portfolio

Co-Portfolio Managers Michael Keough, John Lloyd, and Greg Wilensky are responsible for the day-to-day management of the Portfolio, with no limitation on the authority of one co-portfolio manager in relation to the others.

Michael Keough is Executive Vice President and Co-Portfolio Manager of Flexible Bond Portfolio, which he has co-managed since December 2015. Mr. Keough is also Portfolio Manager of other Janus Henderson accounts. He holds a Bachelor of Science degree in Business/Management from the United States Air Force Academy.

John Lloyd is Lead, Multi-Sector Credit Strategies of Janus Henderson Investors. He is Executive Vice President and Co-Portfolio Manager of Flexible Bond Portfolio, which he has co-managed since June 2024. Mr. Lloyd is also Portfolio Manager of other Janus Henderson accounts. He joined the Adviser as a research analyst in January 2005. Mr. Lloyd holds a Bachelor of Arts degree in Economics from the University of Michigan and a Master of Business Administration degree from Tuck School of Business at Dartmouth College.

26 | Janus Aspen Series

Greg Wilensky, CFA, is Head of U.S. Fixed-Income of Janus Henderson Investors. He is Executive Vice President and Co-Portfolio Manager of Flexible Bond Portfolio, which he has co-managed since February 2020. Mr. Wilensky is also Portfolio Manager of other Janus Henderson accounts. He holds a Bachelor of Science degree in Business Administration from Washington University and a Master of Business Administration degree from the University of Chicago. Mr. Wilensky holds the Chartered Financial Analyst designation.

Conflicts of Interest

27 | Janus Aspen Series

Other information

Classes of Shares

Closed Portfolio Policies

Liquidation/Reorganization of a Portfolio

DISTRIBUTION OF THE Portfolio

28 | Janus Aspen Series

Distributions and taxes

Distributions

Distribution Schedule

How Distributions Affect the Portfolio’s NAV

TAXES

Taxes on Distributions

Taxation of the Portfolio

29 | Janus Aspen Series

Shareholder’s guide

Pricing of portfolio shares

30 | Janus Aspen Series

Distribution, servicing, and administrative fees

Distribution and Shareholder Servicing Plan

Administrative Fees

Payments to financial intermediaries by the Adviser or its affiliates

31 | Janus Aspen Series

Purchases

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Refer to the prospectus of the appropriate insurance company separate account or your plan documents for information on how to invest in the Shares of the Portfolio. Under certain circumstances, the Portfolio may permit an in-kind purchase of Shares. Participating insurance companies and certain other designated organizations are authorized to receive purchase orders on the Portfolio’s behalf. As discussed under “Payments to Financial Intermediaries by the Adviser or its Affiliates,” the Adviser and its affiliates make payments to selected insurance companies, qualified plan service providers, or their affiliates, or other financial intermediaries that were instrumental in the acquisition or retention of accounts for the Portfolio or that provide services in connection with investments in the Portfolio. You should consider such arrangements when evaluating any recommendation of the Portfolio.

32 | Janus Aspen Series

Potential Conflicts

Redemptions

Large Shareholder Redemptions

33 | Janus Aspen Series

Redemptions In-Kind

Excessive trading

Excessive and Short-Term Trading Policies and Procedures

The Janus Henderson funds attempt to deter excessive trading through at least the following methods:

•

fair valuation of securities as described under “Pricing of Portfolio Shares”; and

•

trade monitoring.

The Portfolio’s Trustees may approve from time to time a redemption fee to be imposed by any Janus Henderson fund, subject to 60 days’ notice to shareholders of that fund.

34 | Janus Aspen Series

particular intermediaries may vary depending on the systems’ capabilities, applicable contractual and legal restrictions, and cooperation of those intermediaries.

The Portfolio’s policies and procedures regarding excessive trading may be modified at any time by the Portfolio’s Trustees.

Excessive Trading Risks

Availability of Portfolio Holdings Information

•

35 | Janus Aspen Series

•

Top Holdings. The Portfolio’s top portfolio holdings, in order of position size and as a percentage of the Portfolio’s total portfolio, are available monthly with a 15-day lag.

•

Other Information. The Portfolio may occasionally provide security breakdowns (e.g., industry, sector, regional, market capitalization, and asset allocation) and specific portfolio level performance attribution information and statistics monthly with a 15-day lag. Top/bottom fixed-income issuers ranked by performance attribution, including the percentage attribution to Portfolio performance, average Portfolio weighting, and other relevant data points, may be provided monthly with a 15-day lag.

Shareholder communications

36 | Janus Aspen Series

Financial highlights

Flexible Bond Portfolio – Service Shares

	Years ended December 31
	2024	2023	2022	2021	2020
Net Asset Value, Beginning of Period	$11.16	$10.99	$13.27	$13.99	$12.99
Income/(Loss) from Investment Operations:
Net investment income/(loss)(1)	0.51	0.42	0.25	0.20	0.28
Net realized and unrealized gain/(loss)	(0.33)	0.15	(2.09)	(0.37)	1.05
Total from Investment Operations	0.18	0.57	(1.84)	(0.17)	1.33
Less Dividends and Distributions:
Dividends (from net investment income)	(0.47)	(0.40)	(0.24)	(0.22)	(0.33)
Distributions (from capital gains)	—	—	(0.20)	(0.33)	—
Total Dividends and Distributions	(0.47)	(0.40)	(0.44)	(0.55)	(0.33)
Net Asset Value, End of Period	$10.87	$11.16	$10.99	$13.27	$13.99
Total Return*	1.63%	5.29%	(13.90)%	(1.18)%	10.33%
Net Assets, End of Period (in thousands)	$506,608	$484,490	$444,824	$547,915	$493,364
Ratios to Average Net Assets
Ratio of Gross Expenses	0.87%	0.88%	0.84%	0.84%	0.85%
Ratio of Net Expenses (After Waivers and Expense Offsets)	0.82%	0.82%	0.82%	0.82%	0.84%
Ratio of Net Investment Income/(Loss)	4.56%	3.83%	2.12%	1.47%	2.03%
Portfolio Turnover Rate(2)	188%	203%	182%	160%	139%

*	Total return includes adjustments in accordance with generally accepted accounting principles required at the year or period end and are not annualized for periods of less than one full year. Total return does not include fees, charges, or expenses imposed by the variable annuity and life insurance contracts for which Janus Aspen Series serves as an underlying investment vehicle.
(1)	Per share amounts are calculated based on average shares outstanding during the year or period.
(2)	Portfolio Turnover Rate excludes TBA (to be announced) purchase and sales commitments.

37 | Janus Aspen Series

Glossary of investment terms

Equity and Debt Securities

Collateralized Loan Obligations (“CLOs”) are a type of structured credit, which is a sector of the fixed income market that also includes asset-backed and mortgage- backed securities. Typically organized as a trust or other special purpose vehicle, a CLO issues debt and equity interests and uses the proceeds from this issuance to acquire a portfolio of bank loans made primarily to businesses that are rated below investment grade.

Collateralized Mortgage Obligations (“CMOs”) are a type of mortgage-backed security that are created by dividing the principal and interest payments collected on a pool of mortgages into several revenue streams (tranches) with different priority rights to portions of the underlying mortgage payments. Certain CMO tranches are frequently referred to as “mortgage derivatives” and may be extremely sensitive to changes in interest rates. The issuer of a series of CMOs may elect to be treated as a Real Estate Mortgage Investment Conduit (“REMIC”). A REMIC is a CMO that qualifies for special tax treatment and invests in certain mortgages principally secured by interests in real property and other permitted investments.

Convertible securities are preferred stocks or bonds that pay a fixed dividend or interest payment and are convertible into common stock at a specified price or conversion ratio.

38 | Janus Aspen Series

Mortgage dollar rolls are transactions in which the Portfolio sells a mortgage-related security, such as a security issued by Government National Mortgage Association, to a dealer and simultaneously agrees to purchase a similar security (but not the same security) in the future at a predetermined price. A “dollar roll” can be viewed as a collateralized borrowing in which the Portfolio pledges a mortgage-related security to a dealer to obtain cash.

Pass-through securities are shares or certificates of interest in a pool of debt obligations that have been repackaged by an intermediary, such as a bank or broker-dealer.

Pay-in-kind bonds are debt securities that normally give the issuer an option to pay cash at a coupon payment date or give the holder of the security a similar bond with the same coupon rate and a face value equal to the amount of the coupon payment that would have been made.

Rule 144A securities are securities that are not registered for sale to the general public under the Securities Act of 1933, as amended, but that may be resold to certain institutional investors.

Step coupon bonds are issued and traded at a discount from their face value and pay coupon interest that increases or decreases over the life of the bond. The discount from the face amount or par value depends on the time remaining until cash payments begin, prevailing interest rates, liquidity of the security and the perceived credit quality of the issuer.

39 | Janus Aspen Series

Zero coupon bonds are debt obligations that do not pay regular cash interest payments at regular intervals, but are issued at a discount from face value. The discount approximates the total amount of interest the security will accrue from the date of issuance to maturity. The market value of these securities generally fluctuates more in response to changes in interest rates than interest-paying securities.

Futures, Options, and Other Derivatives

Equity swaps involve the exchange by two parties of future cash flow (e.g., one cash flow based on a referenced interest rate and the other based on the performance of stock or a stock index).

40 | Janus Aspen Series

financial indices including indices of U.S. Government, foreign government, equity, or fixed-income securities. Futures contracts are standardized and traded on designated exchanges.

Interest rate swaps involve the exchange by two parties of their respective commitments to pay or receive interest (e.g., an exchange of floating rate payments for fixed rate payments).

Inverse floaters are debt instruments whose interest rate bears an inverse relationship to the interest rate on another instrument or index. For example, upon reset, the interest rate payable on the inverse floater may go down when the underlying index has risen. Certain inverse floaters may have an interest rate reset mechanism that multiplies the effects of change in the underlying index. Such mechanism may increase the volatility of the security’s market value.

Other Investments, Strategies, and/or Techniques

Repatriation is the ability to move liquid financial assets from a foreign country to an investor’s country of origin.

41 | Janus Aspen Series

janushenderson.com/VIT

151 Detroit Street
Denver, CO 80206-4805
1-877-335-2687

The Trust’s Investment Company Act File No. is 811-7736.

This Prospectus describes Janus Henderson Forty Portfolio (the “Portfolio”), a series of Janus Aspen Series (the “Trust”). Janus Henderson Investors US LLC (the “Adviser”) serves as investment adviser to the Portfolio. The Portfolio currently offers two classes of shares. The Service Shares (the “Shares”) are offered by this Prospectus in connection with investment in and payments under variable annuity contracts and variable life insurance contracts (collectively, “variable insurance contracts”), as well as certain qualified retirement plans.

For the purpose of this Prospectus, any reference to the “Janus Henderson funds” is inclusive of all series of the Trust, collectively, unless otherwise noted in this Prospectus.

Portfolio summary

Janus Henderson Forty Portfolio

Ticker:

N/A

Service Shares

Investment Objective

Janus Henderson Forty Portfolio (“Forty Portfolio”) seeks long-term growth of capital.

Fees and Expenses of the Portfolio

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Management Fees(1)		0.51%
Distribution/Service (12b-1) Fees		0.25%
Other Expenses		0.07%
Total Annual Fund Operating Expenses		0.83%

(1)

This fee may adjust up or down monthly based on the Portfolio’s performance relative to its benchmark index over the performance measurement period. For more information regarding performance-based advisory fees, refer to “Management Expenses” in the Portfolio’s Prospectus.

EXAMPLE:

	1 Year	3 Years	5 Years	10 Years
Service Shares	$ 85	$ 265	$ 460	$ 1,025

Principal investment strategies

The Portfolio pursues its investment objective by normally investing in a portfolio of 30-40 common stocks selected for their growth potential. The Portfolio may invest in companies of any size but will invest primarily in larger, well-established companies. The Portfolio may also invest in foreign securities. The Portfolio is classified as nondiversified, which allows it to hold larger positions in more securities compared to a portfolio that is classified as diversified. As of December 31, 2024, the Portfolio held stocks of 36 companies. Of these holdings, 30 comprised approximately 92.66% of the Portfolio’s holdings.

Portfolio management applies a “bottom-up” approach that focuses on fundamental research and considers, among other factors, a company’s sustainable competitive advantages, long-term growth potential, and shareholder value. The Portfolio will generally consider selling a security when, in portfolio management’s opinion, there is a deterioration in a company’s financials, the investment thesis for owning the position has changed, or if the security exceeds its targeted value.

2 | Janus Henderson Forty Portfolio

Principal investment risks

Nondiversification Risk. The Portfolio is classified as nondiversified under the Investment Company Act of 1940, as amended. This gives portfolio management more flexibility to hold larger positions in more securities. As a result, an increase or decrease in the value of a single security held by the Portfolio may have a greater impact on the Portfolio’s net asset value and total return.

Issuer Concentration Risk. The Portfolio’s holdings may be comprised of a relatively small number of issuers in comparison to other portfolios. As a result, the Portfolio may be subject to greater risks than a portfolio that invests in a greater number of issuers. A change in the value of any single investment held by the Portfolio may affect the overall value of the Portfolio more than it would affect a portfolio that holds more investments. In particular, the Portfolio may be more susceptible to adverse developments affecting any single issuer held by the Portfolio and may be susceptible to greater losses because of these developments. The Portfolio’s policy of concentrating its portfolio in a smaller number of holdings could result in more volatility in the Portfolio’s performance and share price.

Industry and Sector Risk. Although the Portfolio does not concentrate its investments in specific industries, it may have a significant portion of its assets invested in securities of companies conducting similar business or businesses within the same economic sector. Companies in the same industry or economic sector may be similarly affected by negative economic or market events, making the Portfolio more vulnerable to unfavorable developments than portfolios that invest more broadly. As the Portfolio’s holdings become more concentrated, the Portfolio is less able to spread risk and potentially reduce the risk of loss and volatility. As the Portfolio’s holdings change over time, the Portfolio’s exposure to a particular economic sector may become higher or lower.

•

3 | Janus Henderson Forty Portfolio

An investment in the Portfolio is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance information

Annual Total Returns for Service Shares (calendar year-end)

Best Quarter:

2nd Quarter 2020

26.70%

Worst Quarter:

2nd Quarter 2022

– 25.53%

4 | Janus Henderson Forty Portfolio

Average Annual Total Returns (periods ended 12/31/24)
	1 Year	5 Years	10 Years
Forty Portfolio
Service Shares	28.14%	15.12%	15.36%
Russell 1000® Index (reflects no deduction for fees, expenses, or taxes)	24.51%	14.28%	12.87%
Russell 1000® Growth Index (reflects no deduction for fees, expenses, or taxes)	33.36%	18.96%	16.78%
S&P 500® Index (reflects no deduction for fees, expenses, or taxes)	25.02%	14.53%	13.10%

Effective February 25, 2025, the Portfolio changed its broad-based securities market index from the Russell 1000 Growth Index to the Russell 1000 Index due to regulatory requirements. The Portfolio retained the Russell 1000 Growth Index as a performance benchmark because the Russell 1000 Growth Index is more closely aligned with the Portfolio’s investment strategies and investment restrictions. In addition, the Portfolio retained the S&P 500 Index as an additional benchmark. The indices are described below.

•

The Russell 1000 Index measures the performance of the large-cap segment of the U.S. equity universe.

•

The Russell 1000 Growth Index measures the performance of those Russell 1000 companies with higher price-to-book ratios and higher forecasted growth values.

•

The S&P 500 Index is a commonly recognized, market capitalization-weighted index of 500 widely held equity securities, designed to measure broad U.S. equity performance.

Management

Investment Adviser: Janus Henderson Investors US LLC

Portfolio Management: Brian Recht is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since March 2022. Nick Schommer, CFA, is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since January 2016.

Purchase and sale of Portfolio shares

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Redemptions, like purchases, may be effected only through the separate accounts of participating insurance companies or through qualified retirement plans. Requests are duly processed at the net asset value next calculated after an order is received in good order by the Portfolio or its agents. Refer to the appropriate separate account prospectus or plan documents for details.

Tax information

Payments to Insurers, Broker-Dealers, and other financial intermediaries

5 | Janus Henderson Forty Portfolio

Additional information about the Portfolio

Fees and expenses

•

The “Management Fee” is the investment advisory fee rate paid by the Portfolio to the Adviser. Forty Portfolio pays an investment advisory fee rate that adjusts up or down by a variable rate of up to 0.15% (assuming constant assets) on a monthly basis based upon the Portfolio’s performance relative to its benchmark index during a measurement period. This base fee rate, prior to any performance adjustment, is 0.64%. Refer to “Management Expenses” in this Prospectus for additional information with further description in the Statement of Additional Information (“SAI”).

•

“Other Expenses”

•

Additional investment strategies and general portfolio policies

7 | Janus Aspen Series

Security Selection

The Portfolio pursues its investment objective by normally investing in a portfolio of 30-40 common stocks selected for their growth potential. Portfolio management applies a “bottom-up” approach that focuses on fundamental research and considers, among other factors, a company’s sustainable competitive advantages, long-term growth potential, and shareholder value. The Portfolio will generally consider selling a security when, in portfolio management’s opinion, there is a deterioration in a company’s financial, the investment thesis for owning the position has changed, or if the security exceeds its targeted value.

Cash Position

Emerging Markets

Within the parameters of its specific investment policies, the Portfolio may invest in securities of issuers or companies from or with exposure to one or more “developing countries” or “emerging market countries.” Such countries include, but are not limited to, countries included in the MSCI Emerging Markets IndexSM. Emerging market countries in which the Portfolio may invest include frontier market countries, the economies of which are less developed than other emerging market countries. Frontier market countries typically are located in the Asia-Pacific region, Central and Eastern Europe, the Middle East, Central and South America, and Africa.

ESG Integration

Foreign Securities

Illiquid Investments

8 | Janus Aspen Series

Portfolio reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment.

Initial Public Offerings and Secondary Offerings

Nondiversification

Diversification is a way to reduce risk by investing in a broad range of stocks or other securities. The Portfolio is classified as nondiversified. A portfolio that is classified as nondiversified has the ability to take larger positions in more securities than a portfolio that is classified as diversified. This gives a portfolio that is classified as nondiversified more flexibility to focus its investments in companies that portfolio management has identified as the most attractive for the investment objective and strategy of the portfolio. However, because the appreciation or depreciation of a single security may have a greater impact on the net asset value of a portfolio that is classified as nondiversified, its share price can be expected to fluctuate more than a comparable portfolio that is classified as diversified. This fluctuation, if significant, may affect the performance of the portfolio.

Portfolio Turnover

REITs and Real Estate-Related Securities

9 | Janus Aspen Series

and, as a result, are not required to distribute any portion of their income. In this regard, although REOCs do not receive the same favorable tax treatment that is accorded to REITs, REOCs are typically subject to fewer restrictions than REITs, including the ability to retain and/or reinvest funds from operations and more flexibility in terms of the real estate investments they can make.

Securities Lending

Short Sales

Special Situations

10 | Janus Aspen Series

Special situations may include significant changes in a company’s allocation of its existing capital, a restructuring of assets, or a redirection of free cash flow. For example, issuers undergoing significant capital changes may include companies involved in spin-offs, sales of divisions, mergers or acquisitions, companies involved in bankruptcy proceedings, or companies initiating large changes in their debt to equity ratio. Companies that are redirecting cash flows may be reducing debt, repurchasing shares, or paying dividends. Special situations may also result from: (i) significant changes in industry structure through regulatory developments or shifts in competition; (ii) a new or improved product, service, operation, or technological advance; (iii) changes in senior management or other extraordinary corporate event; (iv) differences in market supply of and demand for the security; or (v) significant changes in cost structure. Investments in “special situations” companies can present greater risks than investments in companies not experiencing special situations, and the Portfolio’s performance could be adversely impacted if the securities selected decline in value or fail to appreciate in value.

Other Types of Investments

•

debt securities (such as bonds, notes, sovereign debt, and debentures)

•

preferred stocks and securities convertible into common stocks or preferred stocks

•

indexed/structured securities (such as commercial and residential mortgage- and asset-backed securities)

•

securities purchased on a when-issued, delayed delivery, or forward commitment basis

•

equity and fixed-income securities issued in private placement transactions

Risks of the Portfolio

11 | Janus Aspen Series

Portfolio invests a significant amount of its assets in one or more of these countries, its returns and net asset value may be affected to a large degree by events and economic conditions in such countries. The risks of foreign investing are heightened when investing in emerging markets, which may result in the price of investments in emerging markets experiencing sudden and sharp price swings. In many developing markets, there is less government supervision and regulation of stock exchanges, brokers, and listed companies than in more developed markets, making these investments potentially more volatile in price and less liquid than investments in developed securities markets, resulting in greater risk to investors. There is a risk in developing countries that a current or future economic or political crisis could lead to price controls, forced mergers of companies, expropriation or confiscatory taxation, imposition or enforcement of foreign ownership limits, seizure, nationalization, sanctions or imposition of restrictions by various governmental entities on investment and trading, or creation of government monopolies, any of which may have a detrimental effect on the Portfolio’s investments.

Emerging market countries in which the Portfolio may invest include frontier market countries, which generally have smaller economies and even less developed capital markets than traditional developing markets, and, as a result, the risks of investing in developing market countries are magnified in frontier market countries. The magnification of risks are the result of: potential for extreme price volatility and illiquidity in frontier markets; government ownership or control of parts of private sector and of certain companies; trade barriers, exchange controls, managed adjustments in relative currency values and other protectionist measures imposed or negotiated by other countries; and the relatively new and unsettled securities laws in many frontier market countries.

•

12 | Janus Aspen Series

U.S. dollars even if the security increases in value in its home country. U.S. dollar-denominated securities of foreign issuers may also be affected by currency risk, as the value of these securities may also be affected by changes in the issuer’s local currency.

•

Transaction Costs Risk. Costs of buying, selling, and holding foreign securities, including brokerage, tax, and custody costs, may be higher than those involved in domestic transactions.

•

13 | Janus Aspen Series

sectors of the market where these new issuers operate. Attractive IPOs are often oversubscribed and may not be available to the Portfolio, or may be available only in very limited quantities. The market for IPO issuers has been volatile, and share prices of newly public companies have fluctuated up and down significantly over short periods of time. There can be no assurance that the Portfolio will identify favorable IPO investment opportunities. In addition, under certain market conditions, a relatively small number of companies may issue securities in IPOs. Similarly, as the number of portfolios to which IPO securities are allocated increases, the number of securities issued to any one portfolio may decrease. In addition, as the portfolio increases in size, the impact of IPOs on the portfolio’s performance will generally decrease.

•

14 | Janus Aspen Series

Nondiversification Risk. The Portfolio is classified as nondiversified under the Investment Company Act of 1940, as amended. As a result, an increase or decrease in the value of a single security held by the Portfolio may have a greater impact on the Portfolio’s net asset value and total return. Being nondiversified may also make the Portfolio more susceptible to financial, economic, political, or other developments that may impact a security. Although the Portfolio may satisfy the requirements for a diversified portfolio, and has from time to time operated as diversified, its nondiversified classification gives portfolio management more flexibility to hold larger positions in more securities than a portfolio that is classified as diversified.

15 | Janus Aspen Series

ability to satisfy its debt obligation may be affected by various factors, including its cash flow situation, the extent of its foreign currency reserves, the availability of foreign exchange when a payment is due, the relative size of its debt position in relation to its economy as a whole, the sovereign debtor’s policy toward international lenders, and local political constraints to which the governmental entity may be subject. Sovereign debtors may also be dependent on expected disbursements from foreign governments, multilateral agencies, and other entities. The failure of a sovereign debtor to implement economic reforms, achieve specified levels of economic performance, or repay principal or interest when due may result in the cancellation of third party commitments to lend funds to the sovereign debtor, which may further impair such debtor’s ability or willingness to timely service its debts. The Portfolio may be requested to participate in the rescheduling of such sovereign debt and to extend further loans to governmental entities, which may adversely affect the Portfolio’s holdings. In the event of default, there may be limited or no legal remedies for collecting sovereign debt and there may be no bankruptcy proceedings through which the Portfolio may collect all or part of the sovereign debt that a governmental entity has not repaid. In addition, to the extent the Portfolio invests in non-U.S. sovereign debt, it may be subject to currency risk.

16 | Janus Aspen Series

Management of the Portfolio

Investment adviser

Management expenses

Forty Portfolio pays an investment advisory fee rate that may adjust up or down based on the Portfolio’s performance relative to the cumulative investment record of its performance fee benchmark index (referred to in this section as the “benchmark index”), the Russell 1000 Growth Index, over a rolling 36-month performance measurement period.

The table below reflects the Portfolio’s base fee rate (expressed as an annual rate), as well as the actual compensation rate paid by the Portfolio to the Adviser. The third column shows the full performance rate for outperformance or underperformance during the measurement period relative to the Portfolio’s benchmark index. The fourth column shows the performance

17 | Janus Aspen Series

adjusted investment advisory fee rate, which is equal to the Portfolio’s base fee rate plus or minus the performance adjustment over the period. This fourth column shows the actual compensation rate paid by the Portfolio as of the end of the fiscal year.

As an example, if the Portfolio outperformed its benchmark index over the performance measurement period by its full performance rate (listed in the table below), the advisory fee would increase by 0.15% (assuming constant assets). Conversely, if the Portfolio underperformed its benchmark index over the performance measurement period by its full performance rate (listed in the table below), the advisory fee would decrease by 0.15% (assuming constant assets). Actual performance within the full range of the full performance rate may result in positive or negative incremental adjustments to the advisory fee of greater or less than 0.15%. Additional details discussing the performance fee are included below with further description in the SAI.

Portfolio Name	Base Fee Rate (%)	Full Performance Rate vs. Benchmark Index	Performance Adjusted Investment Advisory Fee Rate/ Actual Compensation Rate Paid to Adviser (%) (for the fiscal year ended December 31, 2024)
Forty Portfolio	0.64	± 8.50%	0.51

The investment advisory fee rate is determined by calculating a base fee (shown in the previous table) and applying a performance adjustment (described in further detail below). The performance adjustment either increases or decreases the base fee depending on how well the Portfolio has performed relative to the Russell 1000 Growth Index.

The calculation of the performance adjustment applies as follows:

Investment Advisory Fee = Base Fee Rate +/– Performance Adjustment

The investment advisory fee rate paid to the Adviser by the Portfolio consists of two components: (1) a base fee calculated by applying the contractual fixed rate of the advisory fee to the Portfolio’s average daily net assets during the previous month (“Base Fee Rate”), plus or minus (2) a performance-fee adjustment (“Performance Adjustment”) calculated by applying a variable rate of up to 0.15% (positive or negative) to the Portfolio’s average daily net assets based on the Portfolio’s relative performance compared to the cumulative investment record of its benchmark index over a 36-month rolling performance measurement period.

No Performance Adjustment is applied unless the difference between the Portfolio’s investment performance and the cumulative investment record of the Portfolio’s benchmark index is 0.50% or greater (positive or negative) during the applicable performance measurement period. The Base Fee Rate is subject to an upward or downward Performance Adjustment for every full 0.50% increment by which the Portfolio outperforms or underperforms its benchmark index. Because the Performance Adjustment is tied to the Portfolio’s relative performance compared to its benchmark index (and not its absolute performance), the Performance Adjustment could increase the Adviser’s fee even if the Portfolio’s Shares lose value during the performance measurement period and could decrease the Adviser’s fee even if the Portfolio’s Shares increase in value during the performance measurement period. For purposes of computing the Base Fee Rate and the Performance Adjustment, net assets are averaged over different periods (average daily net assets during the previous month for the Base Fee Rate, versus average daily net assets during the performance measurement period for the Performance Adjustment). Performance of the Portfolio is calculated net of expenses whereas the Portfolio’s benchmark index does not have any fees or expenses. Reinvestment of dividends and distributions is included in calculating both the performance of the Portfolio and the Portfolio’s benchmark index. The Base Fee Rate is calculated and accrued daily. The Performance Adjustment is calculated monthly in arrears and is accrued throughout the month. The investment advisory fee is paid monthly in arrears. Under extreme circumstances involving underperformance by a rapidly shrinking Portfolio, the dollar amount of the Performance Adjustment could be more than the dollar amount of the Base Fee Rate. In such circumstances, the Adviser would reimburse the Portfolio.

18 | Janus Aspen Series

other class of shares of the Portfolio, as applicable. It is not possible to predict the effect of the Performance Adjustment on future overall compensation to the Adviser since it depends on the performance of the Portfolio relative to the record of the Portfolio’s benchmark index and future changes to the size of the Portfolio.

Portfolio management

Forty Portfolio

Co-Portfolio Managers Brian Recht and Nick Schommer jointly share responsibility for the day-to-day management of the Portfolio, with no limitation on the authority of one co-portfolio manager in relation to the other.

Brian Recht is Executive Vice President and Co-Portfolio Manager of Forty Portfolio, which he has co-managed since March 2022. Mr. Recht is also Portfolio Manager of other Janus Henderson accounts and performs duties as an analyst. He joined the Adviser in 2015. Mr. Recht holds a Bachelor of Arts degree (summa cum laude) in Government from Dartmouth College where he was a member of Phi Beta Kappa. He also holds a Master of Business Administration degree from the Stanford Graduate School of Business and a Juris Doctorate from Stanford Law School.

Nick Schommer, CFA, is Executive Vice President and Co-Portfolio Manager of Forty Portfolio, which he has co-managed since January 2016. Mr. Schommer is also Portfolio Manager of other Janus Henderson accounts. He holds a Bachelor of Science degree in Chemistry from the U.S. Military Academy at West Point, where he was recognized as a Distinguished Cadet and Phi Kappa Phi, and a Master of Business Administration degree from the UCLA Anderson School of Management. Mr. Schommer holds the Chartered Financial Analyst designation.

Conflicts of Interest

19 | Janus Aspen Series

Other information

Classes of Shares

Closed Portfolio Policies

Liquidation/Reorganization of a Portfolio

DISTRIBUTION OF THE Portfolio

20 | Janus Aspen Series

Distributions and taxes

Distributions

Distribution Schedule

How Distributions Affect the Portfolio’s NAV

TAXES

Taxes on Distributions

Taxation of the Portfolio

21 | Janus Aspen Series

Shareholder’s guide

Pricing of portfolio shares

22 | Janus Aspen Series

Distribution, servicing, and administrative fees

Distribution and Shareholder Servicing Plan

Administrative Fees

Payments to financial intermediaries by the Adviser or its affiliates

23 | Janus Aspen Series

access to or information about intermediary personnel, use of an intermediary’s marketing and communication infrastructure, fund analysis tools, data, business planning and strategy sessions with intermediary personnel, information on industry- or platform-specific developments, trends and service providers, and other marketing-related services. Such payments may be in addition to, or in lieu of, the fees described above. These payments are intended to promote the sales of Janus Henderson funds and to reimburse financial intermediaries, directly or indirectly, for the costs that they or their salespersons incur in connection with educational seminars, meetings, and training efforts about the Janus Henderson funds to enable the intermediaries and their salespersons to make suitable recommendations, provide useful services, and maintain the necessary infrastructure to make the Janus Henderson funds available to their customers.

Purchases

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Refer to the prospectus of the appropriate insurance company separate account or your plan documents for information on how to invest in the Shares of the Portfolio. Under certain circumstances, the Portfolio may permit an in-kind purchase of Shares. Participating insurance companies and certain other designated organizations are authorized to receive purchase orders on the Portfolio’s behalf. As discussed under “Payments to Financial Intermediaries by the Adviser or its Affiliates,” the Adviser and its affiliates make payments to selected insurance companies, qualified plan service providers, or their affiliates, or other financial intermediaries that were instrumental in the acquisition or retention of accounts for the Portfolio or that provide services in connection with investments in the Portfolio. You should consider such arrangements when evaluating any recommendation of the Portfolio.

24 | Janus Aspen Series

Potential Conflicts

Redemptions

Large Shareholder Redemptions

Redemptions In-Kind

25 | Janus Aspen Series

redeeming the excess in cash or in-kind. In-kind payment means payment will be made in portfolio securities rather than cash, and may potentially include illiquid investments. Illiquid investments may not be able to be sold quickly or at a price that reflects full value, or there may not be a market for such investments, which could cause the redeeming shareholder to realize losses on the investment if it is sold at a price lower than that at which it had been valued. If the Portfolio makes an in-kind payment, the redeeming shareholder might incur brokerage or other transaction costs to convert the securities to cash, whereas such costs are borne by the Portfolio for cash redemptions.

Excessive trading

Excessive and Short-Term Trading Policies and Procedures

The Janus Henderson funds attempt to deter excessive trading through at least the following methods:

•

fair valuation of securities as described under “Pricing of Portfolio Shares”; and

•

trade monitoring.

The Portfolio’s Trustees may approve from time to time a redemption fee to be imposed by any Janus Henderson fund, subject to 60 days’ notice to shareholders of that fund.

The Portfolio’s policies and procedures regarding excessive trading may be modified at any time by the Portfolio’s Trustees.

26 | Janus Aspen Series

Excessive Trading Risks

Availability of Portfolio Holdings Information

•

Top Holdings. The Portfolio’s top portfolio holdings, in order of position size and as a percentage of the Portfolio’s total portfolio, are available monthly with a 15-day lag.

•

Other Information. The Portfolio may occasionally provide security breakdowns (e.g., industry, sector, regional, market capitalization, and asset allocation) and specific portfolio level performance attribution information and statistics monthly with a 15-day lag. Top/bottom equity securities ranked by performance attribution, including the percentage attribution to Portfolio performance, average Portfolio weighting, and other relevant data points, may be provided monthly with a 15-day lag.

27 | Janus Aspen Series

Financial highlights

Forty Portfolio – Service Shares

	Years ended December 31
	2024	2023	2022	2021	2020
Net Asset Value, Beginning of Period	$42.49	$30.46	$56.64	$52.96	$41.53
Income/(Loss) from Investment Operations:
Net investment income/(loss)(1)	(0.04)	0.05	—(2)	(0.28)	(0.12)
Net realized and unrealized gain/(loss)	11.76	12.03	(19.09)	11.45	15.15
Total from Investment Operations	11.72	12.08	(19.09)	11.17	15.03
Less Dividends and Distributions:
Dividends (from net investment income)	(0.01)	(0.05)	(0.02)	—	(0.08)
Distributions (from capital gains)	(3.14)	—	(7.07)	(7.49)	(3.52)
Total Dividends and Distributions	(3.15)	(0.05)	(7.09)	(7.49)	(3.60)
Net Asset Value, End of Period	$51.06	$42.49	$30.46	$56.64	$52.96
Total Return*	28.14%	39.65%	(33.73)%	22.60%	39.03%
Net Assets, End of Period (in thousands)	$684,881	$609,773	$474,200	$718,925	$634,393
Ratios to Average Net Assets
Ratio of Gross Expenses	0.83%	0.80%	0.80%	1.02%	1.01%
Ratio of Net Expenses (After Waivers and Expense Offsets)	0.83%	0.80%	0.80%	1.02%	1.01%
Ratio of Net Investment Income/(Loss)	(0.08)%	0.14%	0.00%(3)	(0.50)%	(0.27)%
Portfolio Turnover Rate	36%	36%	39%	31%	41%

*	Total return includes adjustments in accordance with generally accepted accounting principles required at the year or period end and are not annualized for periods of less than one full year. Total return does not include fees, charges, or expenses imposed by the variable annuity and life insurance contracts for which Janus Aspen Series serves as an underlying investment vehicle.
(1)	Per share amounts are calculated based on average shares outstanding during the year or period.
(2)	Less than $0.005 on a per share basis.
(3)	Less than 0.005%.

29 | Janus Aspen Series

Glossary of investment terms

Equity and Debt Securities

Convertible securities are preferred stocks or bonds that pay a fixed dividend or interest payment and are convertible into common stock at a specified price or conversion ratio.

30 | Janus Aspen Series

Rule 144A securities are securities that are not registered for sale to the general public under the Securities Act of 1933, as amended, but that may be resold to certain institutional investors.

Futures, Options, and Other Derivatives

Other Investments, Strategies, and/or Techniques

31 | Janus Aspen Series

may not own more than 10% of the outstanding voting securities of an issuer. A portfolio that is classified as nondiversified under the Investment Company Act of 1940, as amended, on the other hand, has the flexibility to take larger positions in securities than a portfolio that is classified as diversified. However, because the appreciation or depreciation of a single security may have a greater impact on the net asset value of a portfolio which is classified as nondiversified, its share price can be expected to fluctuate more than a comparable portfolio which is classified as diversified.

Repatriation is the ability to move liquid financial assets from a foreign country to an investor’s country of origin.

32 | Janus Aspen Series

janushenderson.com/VIT

151 Detroit Street
Denver, CO 80206-4805
1-877-335-2687

The Trust’s Investment Company Act File No. is 811-7736.

This Prospectus describes Janus Henderson Global Research Portfolio (the “Portfolio”), a series of Janus Aspen Series (the “Trust”). Janus Henderson Investors US LLC (the “Adviser”) serves as investment adviser to the Portfolio. The Portfolio currently offers two classes of shares. The Service Shares (the “Shares”) are offered by this Prospectus in connection with investment in and payments under variable annuity contracts and variable life insurance contracts (collectively, “variable insurance contracts”), as well as certain qualified retirement plans.

For the purpose of this Prospectus, any reference to the “Janus Henderson funds” is inclusive of all series of the Trust, collectively, unless otherwise noted in this Prospectus.

Portfolio summary

Janus Henderson Global Research Portfolio

Ticker:

N/A

Service Shares

Investment Objective

Janus Henderson Global Research Portfolio (“Global Research Portfolio”) seeks long-term growth of capital.

Fees and Expenses of the Portfolio

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Management Fees(1)		0.63%
Distribution/Service (12b-1) Fees		0.25%
Other Expenses		0.09%
Total Annual Fund Operating Expenses		0.97%

(1)

EXAMPLE:

	1 Year	3 Years	5 Years	10 Years
Service Shares	$ 99	$ 309	$ 536	$ 1,190

Principal investment strategies

The Portfolio pursues its investment objective by investing primarily in common stocks selected for their growth potential. The Portfolio may invest in companies of any size located anywhere in the world, from larger, well-established companies to smaller, emerging growth companies. The Portfolio typically invests at least 40% of its net assets in securities of issuers or companies that are economically tied to different countries throughout the world, excluding the United States. Because the Portfolio’s investments in foreign securities are partially based on the composition of the Portfolio’s benchmark index, the MSCI World Indexsm, the Portfolio’s exposure to foreign markets may fluctuate in connection with variations in the foreign exposure of the benchmark index.

2 | Janus Henderson Global Research Portfolio

defensible market position, (iii) healthy risk/return profile, (iv) exemplary governance, and (v) attractive valuation. Analysts bring their high-conviction ideas to their respective sector teams. Each sector team compares the appreciation and risk potential of its high-conviction ideas and constructs a sector sleeve that is intended to maximize the best risk-reward opportunities. The sector sleeves are then combined to form the Portfolio’s overall portfolio. The Portfolio Oversight Team, which includes portfolio management, oversees the overall portfolio to manage unintended style risks.

Positions may be sold when, among other things, there is no longer high conviction in the return potential of the investment, if the risk characteristics have caused a re-evaluation of the opportunity, or if the investment thesis for owning a position has changed. This may occur if the stock has appreciated and reflects the anticipated value, if another company represents a better risk-reward opportunity, or if the investment’s fundamental characteristics deteriorate. Securities may also be sold from the portfolio to rebalance sector weightings.

Portfolio management, which includes two analysts on the Central Research Team, oversees the investment process and is responsible for the day-to-day management of the Portfolio. Although the Portfolio’s exposure to certain sectors may be higher than to others, it is expected that the Portfolio will be broadly diversified among a variety of sectors. The Portfolio intends to be fully invested under normal circumstances. However, under unusual circumstances, if the Central Research Team does not have high conviction in enough investment opportunities, the Portfolio’s uninvested assets may be held in cash or similar instruments.

Principal investment risks

3 | Janus Henderson Global Research Portfolio

Currency Risk. Currency risk is the risk that changes in the exchange rate between currencies will adversely affect the value (in U.S. dollar terms) of an investment. As long as the Portfolio holds a foreign security, its value will be affected by the value of the local currency relative to the U.S. dollar. When the Portfolio sells a foreign currency denominated security, its value may be worth less in U.S. dollars even if the security increases in value in its home country. U.S. dollar-denominated securities of foreign issuers may also be affected by currency risk, as the value of these securities may also be affected by changes in the issuer’s local currency.

4 | Janus Henderson Global Research Portfolio

use the collateral to purchase replacement securities in the market. There is a risk that the value of the collateral could decrease below the cost of the replacement security by the time the replacement investment is made, resulting in a loss to the Portfolio.

An investment in the Portfolio is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance information

Annual Total Returns for Service Shares (calendar year-end)

Best Quarter:

2nd Quarter 2020

21.34%

Worst Quarter:

1st Quarter 2020

– 20.73%

Average Annual Total Returns (periods ended 12/31/24)
	1 Year	5 Years	10 Years
Global Research Portfolio
Service Shares	23.27%	12.07%	10.27%
MSCI World IndexSM (reflects no deduction for fees, expenses, or taxes, except foreign withholding taxes)	18.67%	11.17%	9.95%
MSCI All Country World IndexSM (reflects no deduction for fees, expenses, or taxes, except foreign withholding taxes)	17.49%	10.06%	9.23%

The Portfolio’s broad-based benchmark index is the MSCI World Index. The Portfolio’s additional benchmark index is the MSCI All Country World Index. The indices are described below.

•

The MSCI World Index is designed to measure the equity market performance of developed market countries in North America, Europe, and the Asia/Pacific Region.

•

The MSCI All Country World Index is designed to measure equity market performance in global developed and emerging markets.

5 | Janus Henderson Global Research Portfolio

Management

Investment Adviser: Janus Henderson Investors US LLC

Portfolio Management: Joshua Cummings and John Jordan oversee the investment process and are primarily responsible for the day-to-day management of the Portfolio. Joshua Cummings, CFA, is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since January 2024. John Jordan is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since January 2024.

Purchase and sale of Portfolio shares

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Redemptions, like purchases, may be effected only through the separate accounts of participating insurance companies or through qualified retirement plans. Requests are duly processed at the net asset value next calculated after an order is received in good order by the Portfolio or its agents. Refer to the appropriate separate account prospectus or plan documents for details.

Tax information

Payments to Insurers, Broker-Dealers, and other financial intermediaries

6 | Janus Henderson Global Research Portfolio

Additional information about the Portfolio

Fees and expenses

•

The “Management Fee” is the investment advisory fee rate paid by the Portfolio to the Adviser. Global Research Portfolio pays an investment advisory fee rate that adjusts up or down by a variable rate of up to 0.15% (assuming constant assets) on a monthly basis based upon the Portfolio’s performance relative to its benchmark index during a measurement period. This base fee rate, prior to any performance adjustment, is 0.60%. Refer to “Management Expenses” in this Prospectus for additional information with further description in the Statement of Additional Information (“SAI”).

•

“Other Expenses”

•

Additional investment strategies and general portfolio policies

7 | Janus Aspen Series

Security Selection

The Portfolio pursues its investment objective by investing primarily in common stocks selected for their growth potential. The Central Research Team selects investments that represent their high-conviction investment ideas in all market capitalizations, styles, and geographies. The Central Research Team conducts fundamental analysis with a focus on “bottom-up” research, quantitative modeling, and valuation analysis. Using this research process, analysts rate their stocks based upon attractiveness. Stocks considered to be attractive may have all or some of the following characteristics: (i) good and preferably growing free cash flow, (ii) strong and defensible market position, (iii) healthy risk/return profile, (iv) exemplary governance, and (v) attractive valuation. Analysts bring their high-conviction ideas to their respective sector teams. Each sector team compares the appreciation and risk potential of its high-conviction ideas and constructs a sector sleeve that is intended to maximize the best risk-reward opportunities. The sector sleeves are then combined to form the Portfolio’s overall portfolio. The Portfolio Oversight Team, which includes portfolio management, oversees the overall portfolio to manage unintended style risks. Positions may be sold when, among other things, there is no longer high conviction in the return potential of the investment, if the risk characteristics have caused a re-evaluation of the opportunity, or if the investment thesis for owning a position has changed. This may occur if the stock has appreciated and reflects the anticipated value, if another company represents a better risk-reward opportunity, or if the investment’s fundamental characteristics deteriorate. Securities may also be sold from the portfolio to rebalance sector weightings.

Cash Position

Emerging Markets

ESG Integration

Illiquid Investments

8 | Janus Aspen Series

Initial Public Offerings and Secondary Offerings

Leverage

Portfolio Turnover

REITs and Real Estate-Related Securities

9 | Janus Aspen Series

Securities Lending

Short Sales

Special Situations

10 | Janus Aspen Series

regulatory developments or shifts in competition; (ii) a new or improved product, service, operation, or technological advance; (iii) changes in senior management or other extraordinary corporate event; (iv) differences in market supply of and demand for the security; or (v) significant changes in cost structure. Investments in “special situations” companies can present greater risks than investments in companies not experiencing special situations, and the Portfolio’s performance could be adversely impacted if the securities selected decline in value or fail to appreciate in value.

Other Types of Investments

•

debt securities (such as bonds, notes, sovereign debt, and debentures)

•

preferred stocks and securities convertible into common stocks or preferred stocks

•

indexed/structured securities (such as commercial and residential mortgage- and asset-backed securities)

•

securities purchased on a when-issued, delayed delivery, or forward commitment basis

•

equity and fixed-income securities issued in private placement transactions

Risks of the Portfolio

11 | Janus Aspen Series

resulting in greater risk to investors. There is a risk in developing countries that a current or future economic or political crisis could lead to price controls, forced mergers of companies, expropriation or confiscatory taxation, imposition or enforcement of foreign ownership limits, seizure, nationalization, sanctions or imposition of restrictions by various governmental entities on investment and trading, or creation of government monopolies, any of which may have a detrimental effect on the Portfolio’s investments.

Foreign Exposure Risk. The Portfolio invests in foreign debt and equity securities either indirectly (e.g., depositary receipts, depositary shares, and passive foreign investment companies) or directly in foreign markets, including emerging markets. Additional risks may be present with respect to investments in securities of issuers or companies that are economically tied to different countries throughout the world. An issuer is deemed to be economically tied to a country or countries if one or more of the following tests are met: (i) the issuer is organized in, or its primary business office or principal trading market of its equity is located in, the country; (ii) a majority of the issuer’s revenues are derived from one or more countries; or (iii) a majority of the issuer’s assets are located in one or more countries. Investments in foreign securities, including securities of foreign and emerging market governments, may involve greater risks than investing in domestic securities because the Portfolio’s performance may depend on factors other than the performance of a particular company. These factors include:

•

12 | Janus Aspen Series

marketability and may be subject to more abrupt or erratic price movements which could also have a negative effect on the Portfolio. Such factors may hinder the Portfolio’s ability to buy and sell emerging market securities in a timely manner, affecting the Portfolio’s investment strategies and potentially affecting the value of the Portfolio.

•

Transaction Costs Risk. Costs of buying, selling, and holding foreign securities, including brokerage, tax, and custody costs, may be higher than those involved in domestic transactions.

13 | Janus Aspen Series

Portfolio to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet the applicable requirements of the Investment Company Act of 1940, as amended, and the rules thereunder. Increases and decreases in the value of the Portfolio’s holdings will be magnified when the Portfolio uses leverage.

•

14 | Janus Aspen Series

affected by changes in the value of the underlying property owned by the REITs, changes in capital markets and interest rates, management skill in running a REIT, and the creditworthiness of the REIT. The prices of mortgage REITs are affected by the quality of any credit they extend, the creditworthiness of the mortgages they hold, as well as by the value of the property that secures the mortgages. In addition, mortgage REITs (similar to direct investments in mortgage-backed securities) are subject to prepayment risk. Equity REITs and mortgage REITs are subject to heavy cash flow dependency, defaults by borrowers, and self-liquidation. There is also the risk that borrowers under mortgages held by a REIT or lessees of a property that a REIT owns may be unable to meet their obligations to the REIT. In the event of a default by a borrower or lessee, the REIT may incur substantial costs associated with protecting its investments. While equity REITs and mortgage REITs may provide exposure to a large number of properties, such properties may be concentrated in a particular industry, region, or housing type, making such investments more vulnerable to unfavorable developments to economic or market events. Certain “special purpose” REITs in which the Portfolio may invest focus their assets in specific real property sectors, such as hotels, shopping malls, nursing homes, or warehouses, and are therefore subject to the specific risks associated with adverse developments in these sectors. The Portfolio’s shareholders will indirectly bear their proportionate share of the REIT’s expenses, in addition to their proportionate share of the Portfolio’s expenses. The value of investments in REOCs will generally be affected by the same factors that adversely affect REIT investments; however, REOCs may also be adversely affected by income streams derived from businesses other than real estate ownership.

Warrants and Rights Risk. The price, performance and liquidity of warrants and rights to purchase equity securities are typically linked to the underlying stock. These instruments have many characteristics of convertible securities and, similarly, will react to variations in the general market for equity securities. Rights are similar to warrants, but normally have a short duration and are distributed directly by the issuer to its shareholders. Rights and warrants have no voting rights, receive no dividends and have no rights with respect to the assets of the issuer.

15 | Janus Aspen Series

Management of the Portfolio

Investment adviser

Management expenses

Global Research Portfolio pays an investment advisory fee rate that may adjust up or down based on the Portfolio’s performance relative to the cumulative investment record of its performance fee benchmark index (referred to in this section as the “benchmark index”), the MSCI World Index, over a rolling 36-month performance measurement period.

16 | Janus Aspen Series

Portfolio Name	Base Fee Rate (%)	Full Performance Rate vs. Benchmark Index	Performance Adjusted Investment Advisory Fee Rate/ Actual Compensation Rate Paid to Adviser (%) (for the fiscal year ended December 31, 2024)
Global Research Portfolio	0.60	± 6.00%	0.63

The calculation of the performance adjustment applies as follows:

Investment Advisory Fee = Base Fee Rate +/– Performance Adjustment

17 | Janus Aspen Series

Portfolio management

Global Research Portfolio

The Central Research Team selects investments for Global Research Portfolio and has done so since May 2013. The Central Research Team consists of the Adviser’s equity research analysts. The Portfolio Oversight Team oversees the Portfolio’s holdings. Joshua Cummings and John Jordan are members of the Portfolio Oversight Team and are primarily responsible for the day-to-day management of the Portfolio.

Joshua Cummings, CFA, is Head of the Consumer Sector Team and the Communications Sector Team at Janus Henderson Investors. He is Executive Vice President and Co-Portfolio Manager of Global Research Portfolio, which he has co-managed since January 2024. Mr. Cummings is also Portfolio Manager of other Janus Henderson accounts and performs duties as an analyst. He joined the Adviser in 2016. He holds a Bachelor of Arts degree in Economics from Colby College and a Master of Business Administration degree in Finance and Accounting from New York University. Mr. Cummings holds the Chartered Financial Analyst designation.

John Jordan is Head of the Financials Sector Team at Janus Henderson Investors. He is Executive Vice President and Co-Portfolio Manager of Global Research Portfolio, which he has co-managed since January 2024. Mr. Jordan is also Portfolio Manager of other Janus Henderson accounts and performs duties as an analyst. He joined the Adviser in 2008. He holds a Bachelor of Arts degree in History and Economics from the University of Virginia where he graduated with high distinction and was a member of Phi Beta Kappa. Mr. Jordan also holds a Juris Doctor from Yale Law School.

Conflicts of Interest

18 | Janus Aspen Series

Other information

Classes of Shares

Closed Portfolio Policies

Liquidation/Reorganization of a Portfolio

DISTRIBUTION OF THE Portfolio

19 | Janus Aspen Series

Distributions and taxes

Distributions

Distribution Schedule

How Distributions Affect the Portfolio’s NAV

TAXES

Taxes on Distributions

Taxation of the Portfolio

20 | Janus Aspen Series

Shareholder’s guide

Pricing of portfolio shares

21 | Janus Aspen Series

Distribution, servicing, and administrative fees

Distribution and Shareholder Servicing Plan

Administrative Fees

Payments to financial intermediaries by the Adviser or its affiliates

22 | Janus Aspen Series

Purchases

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Refer to the prospectus of the appropriate insurance company separate account or your plan documents for information on how to invest in the Shares of the Portfolio. Under certain circumstances, the Portfolio may permit an in-kind purchase of Shares. Participating insurance companies and certain other designated organizations are authorized to receive purchase orders on the Portfolio’s behalf. As discussed under “Payments to Financial Intermediaries by the Adviser or its Affiliates,” the Adviser and its affiliates make payments to selected insurance companies, qualified plan service providers, or their affiliates, or other financial intermediaries that were instrumental in the acquisition or retention of accounts for the Portfolio or that provide services in connection with investments in the Portfolio. You should consider such arrangements when evaluating any recommendation of the Portfolio.

23 | Janus Aspen Series

Potential Conflicts

Redemptions

Large Shareholder Redemptions

Redemptions In-Kind

24 | Janus Aspen Series

Excessive trading

Excessive and Short-Term Trading Policies and Procedures

The Janus Henderson funds attempt to deter excessive trading through at least the following methods:

•

fair valuation of securities as described under “Pricing of Portfolio Shares”; and

•

trade monitoring.

The Portfolio’s Trustees may approve from time to time a redemption fee to be imposed by any Janus Henderson fund, subject to 60 days’ notice to shareholders of that fund.

The Portfolio’s policies and procedures regarding excessive trading may be modified at any time by the Portfolio’s Trustees.

25 | Janus Aspen Series

Excessive Trading Risks

Availability of Portfolio Holdings Information

•

Top Holdings. The Portfolio’s top portfolio holdings, in order of position size and as a percentage of the Portfolio’s total portfolio, are available monthly with a 15-day lag.

•

Other Information. The Portfolio may occasionally provide security breakdowns (e.g., industry, sector, regional, market capitalization, and asset allocation) and specific portfolio level performance attribution information and statistics monthly with a 15-day lag. Top/bottom equity securities ranked by performance attribution, including the percentage attribution to Portfolio performance, average Portfolio weighting, and other relevant data points, may be provided monthly with a 15-day lag.

26 | Janus Aspen Series

Financial highlights

Global Research Portfolio – Service Shares

	Years ended December 31
	2024	2023	2022	2021	2020
Net Asset Value, Beginning of Period	$59.01	$48.41	$69.31	$62.00	$55.27
Income/(Loss) from Investment Operations:
Net investment income/(loss)(1)	0.32	0.37	0.38	0.21	0.25
Net realized and unrealized gain/(loss)	13.29	12.24	(14.11)	10.62	9.77
Total from Investment Operations	13.61	12.61	(13.73)	10.83	10.02
Less Dividends and Distributions:
Dividends (from net investment income)	(0.41)	(0.42)	(0.50)	(0.25)	(0.30)
Distributions (from capital gains)	(2.24)	(1.59)	(6.67)	(3.27)	(2.99)
Total Dividends and Distributions	(2.65)	(2.01)	(7.17)	(3.52)	(3.29)
Net Asset Value, End of Period	$69.97	$59.01	$48.41	$69.31	$62.00
Total Return*	23.29%	26.45%	(19.61)%	17.80%	19.76%
Net Assets, End of Period (in thousands)	$275,698	$231,174	$199,513	$258,922	$235,787
Ratios to Average Net Assets
Ratio of Gross Expenses	0.97%	0.86%	0.89%	1.02%	1.09%
Ratio of Net Expenses (After Waivers and Expense Offsets)	0.97%	0.86%	0.89%	1.02%	1.09%
Ratio of Net Investment Income/(Loss)	0.48%	0.69%	0.73%	0.32%	0.47%
Portfolio Turnover Rate	31%	25%	32%	20%	33%

*	Total return includes adjustments in accordance with generally accepted accounting principles required at the year or period end and are not annualized for periods of less than one full year. Total return does not include fees, charges, or expenses imposed by the variable annuity and life insurance contracts for which Janus Aspen Series serves as an underlying investment vehicle.
(1)	Per share amounts are calculated based on average shares outstanding during the year or period.

28 | Janus Aspen Series

Glossary of investment terms

Equity and Debt Securities

Convertible securities are preferred stocks or bonds that pay a fixed dividend or interest payment and are convertible into common stock at a specified price or conversion ratio.

29 | Janus Aspen Series

Rule 144A securities are securities that are not registered for sale to the general public under the Securities Act of 1933, as amended, but that may be resold to certain institutional investors.

Futures, Options, and Other Derivatives

Equity swaps involve the exchange by two parties of future cash flow (e.g., one cash flow based on a referenced interest rate and the other based on the performance of stock or a stock index).

30 | Janus Aspen Series

Other Investments, Strategies, and/or Techniques

Repatriation is the ability to move liquid financial assets from a foreign country to an investor’s country of origin.

31 | Janus Aspen Series

janushenderson.com/VIT

151 Detroit Street
Denver, CO 80206-4805
1-877-335-2687

The Trust’s Investment Company Act File No. is 811-7736.

This Prospectus describes Janus Henderson Global Sustainable Equity Portfolio (the “Portfolio”), a series of Janus Aspen Series (the “Trust”). Janus Henderson Investors US LLC (the “Adviser”) serves as investment adviser to the Portfolio. The Portfolio currently offers two classes of shares. The Service Shares (the “Shares”) are offered by this Prospectus in connection with investment in and payments under variable annuity contracts and variable life insurance contracts (collectively, “variable insurance contracts”), as well as certain qualified retirement plans.

For the purpose of this Prospectus, any reference to the “Janus Henderson funds” is inclusive of all series of the Trust, collectively, unless otherwise noted in this Prospectus.

Portfolio summary

Janus Henderson Global Sustainable Equity Portfolio

Ticker:

N/A

Service Shares

Investment Objective

Janus Henderson Global Sustainable Equity Portfolio (“Global Sustainable Equity Portfolio”) seeks long-term growth of capital.

Fees and Expenses of the Portfolio

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		0.75%
Distribution/Service (12b-1) Fees		0.25%
Other Expenses		1.86%
Total Annual Fund Operating Expenses		2.86%
Fee Waiver and/or Expense Reimbursement(1)		1.87%
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement(1)		0.99%

(1)

EXAMPLE:

The Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated, reinvest all dividends and distributions, and then redeem all of your Shares at the end of each period. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses are equal to the Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement for the first year and the Total Annual Fund Operating Expenses thereafter. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years	5 Years	10 Years
Service Shares	$ 101	$ 709	$ 1,343	$ 3,050

Principal investment risks

The Portfolio pursues its investment objective by investing, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities. The Portfolio will typically invest in companies whose products and services are considered by portfolio management as contributing to positive environmental or social change and sustainable economic development, including those that are strategically aligned with environmental and social megatrends such as climate change, resource constraints, growing populations, and aging populations.

2 | Janus Henderson Global Sustainable Equity Portfolio

The Portfolio typically invests at least 40% of its net assets in securities of issuers or companies that are economically tied to different countries throughout the world, excluding the United States. An issuer is deemed to be economically tied to a country or countries if one or more of the following tests are met: (i) the issuer is organized in, or its primary business office or principal trading market of its equity is located in, the country; (ii) a majority of the issuer’s revenues are derived from one or more countries; or (iii) a majority of the issuer’s assets are located in one or more countries. The Portfolio’s investments may be in non-U.S. currency or U.S. dollar-denominated.

The Portfolio generally invests in a core group of 50-70 equity securities, which consist primarily of common stocks, but may also include other types of instruments, such as depositary receipts and warrants. The Portfolio may also invest in real estate investment trusts (“REITs”). The Portfolio will invest primarily in larger, well-established companies but may also invest in mid- and small-sized companies. The Portfolio’s uninvested assets may be held in cash or cash equivalents.

In selecting investments, portfolio management employs a “bottom-up” approach that focuses on fundamental research. To identify the universe of investible securities for the Portfolio, portfolio management first employs positive selection criteria that seeks to identify companies that derive at least 50% of their current or future expected revenues from at least one of ten environmental and social themes. Environmental themes include efficiency, cleaner energy, water management, environmental services, and sustainable transport. Social themes include sustainable property and finance, safety, quality of life, knowledge and technology, and health.

Next, portfolio management applies broad-based negative screens, which incorporate third-party inputs, to seek to avoid securities of issuers that, in the determination of the Adviser, are significantly engaged in or derive more than de minimis revenue from industries, activities, or assets considered by portfolio management to have a negative impact on society or the environment. A current list of such industries, activities, or assets, which may evolve over time, follows:

•

alcohol;

•

animal testing (non-medical);

•

chemicals of concern;

•

civilian firearms and ammunition;

•

controversial weapons;

•

conventional weapons;

•

fossil fuels;

•

fur;

•

gambling;

•

genetically modified organisms;

•

human stem cell research;

•

intensive farming;

•

nuclear power generation;

•

pornography;

•

tobacco; and

•

United Nations Global Compact and Organization for Economic Co-operation and Development violators.

In selecting investments, portfolio management will then consider, among other factors, a company’s growth potential, competitive positioning, operational quality, and strategy. Portfolio management may also consider factors such as a company’s historic and projected return on capital, balance sheets, and financial models. Portfolio management will also consider environmental, social, and governance (“ESG”) factors (“ESG Factors”), which may include climate change, deforestation, biodiversity, human rights, company culture, community relations, board structure and diversity, executive pay, and corporate reporting. Portfolio management seeks to maintain a portfolio of securities that has a carbon footprint and carbon intensity that is at least 20% below the MSCI World Indexsm. At portfolio management’s discretion, the Portfolio will engage with a company’s management regarding matters that may include shareholder rights, governance and remuneration, climate change, carbon emissions, pollution, biodiversity, human capital, and diversity and inclusion.

Portfolio management evaluates and applies ESG and sustainable investment criteria relying on a mix of third-party data and internally-generated analyses based on information that may include web-based research reports from a company or independent sources, as well as corporate engagement. Portfolio management does not apply these ESG and sustainable investment criteria in managing the Portfolio’s exposure to cash and cash equivalents.

3 | Janus Henderson Global Sustainable Equity Portfolio

The Portfolio will generally consider selling a stock if, in portfolio management’s opinion, there has been a regulatory, industry, or position-level change that may impair a company’s revenue growth. The Portfolio will also consider selling a stock if, in portfolio management’s opinion, the company’s business model no longer meets the ESG and sustainable investment criteria employed in managing the Portfolio.

Principal investment risks

The biggest risk is that the Portfolio’s returns will vary, and you could lose money. The Portfolio invests primarily in common stocks, which tend to be more volatile than many other investment choices. The principal risks associated with investing in the Portfolio are set forth below.

Sustainable Investment Risk. The Portfolio follows a sustainable investment approach by investing in companies that relate to certain sustainable development themes and demonstrate adherence to ESG practices. Accordingly, the Portfolio may have a significant portion of its assets invested in securities of companies conducting similar business or businesses within the same economic sector, which may make the Portfolio more vulnerable to unfavorable developments in a particular sector than portfolios that invest more broadly. Additionally, due to its exclusionary criteria, the Portfolio may not be invested in certain industries or sectors, and therefore may have lower performance than portfolios that do not apply similar criteria. In addition, because sustainable and ESG investing takes into consideration factors beyond traditional financial analysis, the investment opportunities for the Portfolio may be limited at times. Sustainability and ESG-related information provided by issuers and third parties, upon which portfolio management may rely, continues to develop, and may be incomplete, inaccurate, use different methodologies, or be applied differently across companies and industries. As the regulatory landscape around responsible investing continues to evolve across regions, future rules and regulations may require the Portfolio to modify or alter its investment process. There is also a risk that the companies identified through the investment process may fail to adhere to sustainable and/or ESG-related business practices, which may result in the Portfolio selling a security when it might otherwise be disadvantageous to do so.

Industry and Sector Risk. Although the Portfolio does not concentrate its investments in specific industries, it emphasizes certain themes and megatrends. As a result, at times, it may have a significant portion of its assets invested in securities of companies conducting similar business or businesses within the same economic sector or that benefit from the same megatrend. Companies in the same industry or economic sector or that benefit from the same megatrend may be similarly affected by economic or market events, making the Portfolio more vulnerable to unfavorable developments than portfolios that invest more broadly. As the Portfolio’s holdings become more concentrated, the Portfolio is less able to spread risk and potentially reduce the risk of loss and volatility.

•

Industrials Sector Risk. The industrials sector is comprised of companies who produce capital goods used in construction and manufacturing, such as companies that make and sell machinery, equipment, and supplies that are used to produce other goods. Companies in the industrials sector may be adversely affected by changes in government regulation and spending, import controls, and worldwide competition. In addition, companies may be adversely affected by environmental damages, product liability claims and exchange rates, and may face product obsolescence due to rapid technological developments and frequent new product introduction.

•

4 | Janus Henderson Global Sustainable Equity Portfolio

multiple companies or securities, in the portfolio decreases. Further, regardless of how well individual companies or securities perform, the value of the Portfolio’s holdings could also decrease if there are deteriorating economic or market conditions or perceptions regarding the industries in which the issuers of securities the Portfolio holds participate.

Portfolio Management Risk. The Portfolio is an actively managed investment portfolio and is therefore subject to the risk that portfolio management may not be successful in identifying investment opportunities that are aligned with the sustainable investment approach that the Portfolio employs. Accordingly, the Portfolio may underperform its benchmark index or other mutual funds with similar investment objectives.

Small- and Mid-Sized Companies Risk. Investments in securities issued by small- and mid-sized companies, which can include smaller, start-up companies offering emerging products or services, may involve greater risks than are customarily associated with larger, more established companies. For example, small- and mid-sized companies may suffer more significant losses as a result of their narrow product lines, limited operating history, greater exposure to competitive threats, limited financial resources, limited trading markets, and the potential lack of management depth. Securities issued by small- and mid-sized companies tend to be more volatile and somewhat more speculative than securities issued by larger or more established companies and may underperform as compared to the securities of larger or more established companies. These holdings are also subject to wider price fluctuations and tend to be less liquid than stocks of larger or more established companies, which could have a significant adverse effect on the Portfolio’s returns, especially as market conditions change.

REIT Risk. REITs are subject to certain risks inherent in the direct ownership of real estate, including without limitation, a possible lack of mortgage funds and associated interest rate risks, overbuilding, property vacancies, increases in property taxes and operating expenses, changes in zoning laws, losses due to environmental damages and changes in neighborhood values and appeal to purchasers. In addition, a REIT could fail to qualify for tax-free pass-through of its income under the Internal Revenue Code of 1986, as amended, or fail to maintain its exemption from registration under the Investment Company Act of 1940, as amended, which could produce adverse economic consequences for the REIT and its investors, including the Portfolio. Dividends received by the Portfolio from a REIT generally will not constitute qualified dividend income.

New/Smaller Sized Portfolio Risk. Because the Portfolio is relatively new, it has a limited operating history and a small asset base. The Portfolio’s performance may not represent how the Portfolio is expected to or may perform in the long term if and when it becomes larger. If the Portfolio were to fail to attract sufficient assets to achieve or maintain economies of scale, its

5 | Janus Henderson Global Sustainable Equity Portfolio

performance may be negatively impacted, and any resulting liquidation could create negative transaction costs for the Portfolio and tax consequences for investors.

Depositary Receipts Risk. Depositary receipts are generally subject to the same sort of risks as direct investments in a foreign country, such as currency risk, market risk, and foreign exposure risk, because their values depend on the performance of a foreign security denominated in its home currency.

Warrants Risk. The price, performance and liquidity of warrants to purchase equity securities are typically linked to the underlying stock. These instruments have many characteristics of convertible securities and, similarly, will react to variations in the general market for equity securities.

An investment in the Portfolio is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance information

The following information provides some indication of the risks of investing in the Portfolio by showing how the Portfolio’s performance has varied over time. The bar chart depicts the change in performance from year to year during the periods indicated. Total return figures include the effect of the Portfolio’s expenses, but do not include charges or expenses attributable to any insurance product, which would lower the performance illustrated. The table compares the average annual returns for the Service Shares of the Portfolio for the periods indicated to a broad-based securities market index. All figures assume reinvestment of dividends and distributions. For certain periods, the Portfolio’s performance reflects the effect of expense waivers. Without the effect of these expense waivers, the performance shown would have been lower.

Annual Total Returns for Service Shares (calendar year-end)

Best Quarter:

4th Quarter 2023

13.63%

Worst Quarter:

3rd Quarter 2023

– 7.42%

Average Annual Total Returns (periods ended 12/31/24)
	1 Year	Since Inception 1/26/22
Global Sustainable Equity Portfolio
Service Shares	11.01%	5.52%
MSCI World IndexSM (reflects no deduction for fees, expenses, or taxes, except foreign withholding taxes)	18.67%	9.48%

The Portfolio’s broad-based benchmark index is the MSCI World Index. The index is described below.

•

The MSCI World Index is designed to measure the equity market performance of developed market countries in North America, Europe, and the Asia/Pacific Region.

6 | Janus Henderson Global Sustainable Equity Portfolio

Management

Investment Adviser: Janus Henderson Investors US LLC

Portfolio Management: Hamish Chamberlayne, CFA, is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since inception. Aaron Scully, CFA, is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since inception.

Purchase and sale of Portfolio shares

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Redemptions, like purchases, may be effected only through the separate accounts of participating insurance companies or through qualified retirement plans. Requests are duly processed at the net asset value next calculated after an order is received in good order by the Portfolio or its agents. Refer to the appropriate separate account prospectus or plan documents for details.

Tax information

Payments to Insurers, Broker-Dealers, and other financial intermediaries

7 | Janus Henderson Global Sustainable Equity Portfolio

Additional information about the Portfolio

Fees and expenses

•

“Other Expenses”

•

Additional investment strategies and general portfolio policies

The Portfolio’s Board of Trustees (“Trustees”) may change the Portfolio’s investment objective or non-fundamental principal investment strategies without a shareholder vote. The Portfolio will notify you in writing at least 60 days before making any such change it considers material. In addition, the Portfolio will provide shareholders with at least 60 days’ notice prior to changing the 80% investment policy. If there is a material change to the Portfolio’s investment objective or principal investment strategies, you should consider whether the Portfolio remains an appropriate investment for you. There is no guarantee that the Portfolio will achieve its investment objective.

8 | Janus Aspen Series

not be required to dispose of any securities. The “Glossary of Investment Terms” includes descriptions of investment terms used throughout the Prospectus.

Security Selection

The Portfolio pursues its investment objective by investing, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities. In selecting investments, portfolio management employs a “bottom-up” approach that focuses on fundamental research. To identify the universe of investible securities for the Portfolio, portfolio management first employs positive selection criteria that seeks to identify companies that derive at least 50% of their current or future expected revenues from at least one of ten environmental and social themes. Environmental themes include efficiency, cleaner energy, water management, environmental services, and sustainable transport. Social themes include sustainable property and finance, safety, quality of life, knowledge and technology, and health.

Next, portfolio management applies broad-based negative screens, which incorporate third-party inputs, to seek to avoid securities of issuers that, in the determination of the Adviser, are significantly engaged in or derive more than de minimis revenue (generally no more than 5-10%, except as noted below) from industries, activities, or assets considered by portfolio management to have a negative impact on society or the environment. A current list of such industries, activities, or assets, which may evolve over time, follows:

•

alcohol;

•

animal testing (non-medical);

•

chemicals of concern;

•

civilian firearms and ammunition;

•

controversial weapons;

•

conventional weapons;

•

fossil fuels;

•

fur;

•

gambling;

•

genetically modified organisms;

•

human stem cell research;

•

intensive farming;

•

nuclear power generation;

•

pornography;

•

tobacco; and

•

United Nations Global Compact and Organization for Economic Co-operation and Development violators.

In screening such investments, there may be instances where the de minimis limits cannot be expressed quantitatively, in which case portfolio management applies a qualitative assessment of an issuer. Among other things, the qualitative assessment looks at the extent to which an “avoided” activity is part of a company’s business, whether a company is taking action to address and improve upon such activity, and may consider certain issuers, industries or sectors that are in the process of transitioning to sustainable business practices, in which case a threshold of greater than 5-10% may initially be applied.

Issuers are excluded if they derive any revenue from controversial weapons, fossil fuels, or tobacco production. As it relates to the fossil fuels exclusion, portfolio management may invest in issuers generating power from natural gas if the issuer’s strategy involves a transition to renewable energy power generation and they have a carbon intensity aligned with the Paris Agreement on Climate Change.

In addition, portfolio management applies screens to exclude direct investment in:

•

Any issuer whose head office is located in a country or territory included in the latest available version of the European Union’s list of countries and territories not cooperating on tax issuers;

•

Any issuer whose registered office is domiciled in a country or territory on the financial Action Task force blacklist or greylist; and

•

Any issuer that derives 50% or more of its revenues from electricity generation with a greenhouse gas intensity that exceeds certain thresholds for power sector emissions intensity.

9 | Janus Aspen Series

historic and projected return on capital, balance sheets, and financial models. Portfolio management will also consider ESG Factors, which, for this Portfolio, may include climate change, deforestation, biodiversity, human rights, company culture, community relations, board structure and diversity, executive pay, and corporate reporting. Portfolio management seeks to maintain a portfolio of securities that has a carbon footprint and carbon intensity that is at least 20% below the MSCI World Index. At portfolio management’s discretion, the Portfolio will engage with a company’s management regarding matters that may include shareholder rights, governance and remuneration, climate change, carbon emissions, pollution, biodiversity, human capital, and diversity and inclusion.

Portfolio management does not apply these ESG and sustainable investment criteria in managing the Portfolio’s exposure to cash and cash equivalents.

Cash Position

Emerging Markets

Illiquid Investments

Initial Public Offerings and Secondary Offerings

Leverage

10 | Janus Aspen Series

REITs and Real Estate-Related Securities

The Portfolio may invest in equity and debt securities of real estate-related companies. These securities may include common stocks, preferred stocks, and other securities, including, but not limited to, mortgage-backed securities, real estate-backed securities, securities of REITs and similar REIT-like entities (such as real estate operating companies (“REOCs”)). A REIT is an entity that invests in real estate-related projects, such as properties, mortgage loans, and construction loans. REITs are often categorized as equity REITs, mortgage REITs, and hybrid REITs. An equity REIT, the most common type of REIT, invests primarily in the fee ownership of land and buildings. An equity REIT derives its income primarily from rental income but may also realize capital gains or losses by selling real estate properties in its portfolio that have appreciated or depreciated in value. A mortgage REIT invests primarily in mortgages on real estate, which may secure construction, development, or long-term loans. A mortgage REIT generally derives its income from interest payments on the credit it has extended. A hybrid REIT combines the characteristics of equity REITs and mortgage REITs, generally by holding both ownership interests and mortgage interests in real estate.

Short Sales

11 | Janus Aspen Series

Special Situations

Sustainable Investing

Sustainable investing is an investment approach that focuses on companies that are related to certain sustainable development themes, including those that are strategically aligned with environmental and social megatrends such as climate change, resource constraints, growing populations, and aging populations.

Other Types of Investments

•

preferred stocks and securities convertible into common stocks or preferred stocks

•

equity securities issued in private placement transactions

Risks of the Portfolio

The value of your investment will vary over time, sometimes significantly, and you may lose money by investing in the Portfolio. The following information is intended to help you better understand some of the risks of investing in the Portfolio, including those risks that are summarized in the Portfolio Summary section. This information also includes descriptions of other risks the Portfolio may be subject to as a result of additional investment strategies and general policies that may apply to the Portfolio. The impact of the following risks on the Portfolio may vary depending on the Portfolio’s investments. The greater the Portfolio’s investment in a particular security, the greater the Portfolio’s exposure to the risks associated with that security. Before investing in the Portfolio, you should consider carefully the risks that you assume when investing in the Portfolio.

12 | Janus Aspen Series

that the Portfolio focuses its transactions with a limited number of counterparties, it will have greater exposure to the risks associated with one or more counterparties.

Emerging Markets Risk. The Portfolio may invest in securities of issuers or companies from or with exposure to one or more “developing countries” or “emerging market countries.” Such countries include, but are not limited to, countries included in the MSCI Emerging Markets Index. To the extent that the Portfolio invests a significant amount of its assets in one or more of these countries, its returns and net asset value may be affected to a large degree by events and economic conditions in such countries. The risks of foreign investing are heightened when investing in emerging markets, which may result in the price of investments in emerging markets experiencing sudden and sharp price swings. In many developing markets, there is less government supervision and regulation of stock exchanges, brokers, and listed companies than in more developed markets, making these investments potentially more volatile in price and less liquid than investments in developed securities markets, resulting in greater risk to investors. There is a risk in developing countries that a current or future economic or political crisis could lead to price controls, forced mergers of companies, expropriation or confiscatory taxation, imposition or enforcement of foreign ownership limits, seizure, nationalization, sanctions or imposition of restrictions by various governmental entities on investment and trading, or creation of government monopolies, any of which may have a detrimental effect on the Portfolio’s investments.

ESG Investment Risk. Because the Portfolio considers ESG Factors (as defined in the Portfolio Summary) in selecting securities, the Portfolio may perform differently than portfolios that do not consider ESG Factors. Due to the ESG considerations and exclusionary criteria employed by the Portfolio, the Portfolio may not be invested in certain industries or sectors, and therefore may have lower performance than portfolios that do not apply similar criteria. ESG-related information provided by issuers and third parties, upon which portfolio management may utilize, continues to develop, and may be incomplete, inaccurate, use different methodologies, or be applied differently across companies and industries. Further, the regulatory landscape for ESG investing in the United States is still developing and future rules and regulations may require the Portfolio to modify or alter its investment process. Similarly, government policies incentivizing companies to consider their environmental or social practices may fall out of favor, which could potentially limit the Portfolio’s investment universe. There is also a risk that the issuers identified through the investment process employed by the Portfolio may fail to adhere to positive environmental or social practices, which may result in selling a security when it might otherwise be disadvantageous to do so.

•

13 | Janus Aspen Series

•

Transaction Costs Risk. Costs of buying, selling, and holding foreign securities, including brokerage, tax, and custody costs, may be higher than those involved in domestic transactions.

•

European Investments Risk. Exposure to investments in European countries may expose the Portfolio to the economic and political risks associated with Europe in general and the specific European countries in which it invests. The economies and markets of European countries are often closely connected and interdependent, and events in one European country can have an adverse impact on other European countries. The Portfolio may be exposed to investments in securities of issuers that are domiciled in, have significant operations in, or that are listed on at least one securities exchange within member states of the European Union (the “EU”). A number of countries within the EU are also members of the Economic and Monetary Union (the “EMU”) (together, with the EU, the “eurozone”) and have adopted the euro as their currency. Eurozone membership requires member states to comply with restrictions on inflation rates, deficits, interest rates, debt levels and fiscal and monetary controls, each of which may significantly affect every country in Europe. Changes in import or export tariffs, changes in governmental or EU regulations on trade, changes in the exchange rate of the euro and other currencies of certain EU countries which are not in the eurozone, the default or threat of default by an EU member state on its sovereign debt, and/or an economic recession in an EU member state may have a significant adverse effect on the economies of other EU member states and major trading partners outside Europe.

14 | Janus Aspen Series

sectors may share common characteristics and are more likely to react similarly to industry-specific market or economic developments. The Portfolio’s investments, if any, in multiple companies in a particular industry or economic sector may increase the Portfolio’s exposure to industry and sector risk.

•

15 | Janus Aspen Series

•

16 | Janus Aspen Series

since sustainable and ESG investing takes into consideration factors beyond traditional financial analysis, the investment opportunities for the Portfolio may be limited at times. Sustainability and ESG-related information provided by issuers and third parties, upon which portfolio management may rely, continues to develop, and may be incomplete, inaccurate, use different methodologies, or be applied differently across companies and industries. As the regulatory landscape around responsible investing continues to evolve across regions, future rules and regulations may require the Portfolio to modify or alter its investment process. There is also a risk that the companies identified through the investment process may fail to adhere to sustainable and/or ESG-related business practices, which may result in the Portfolio selling a security when it might otherwise be disadvantageous to do so.

17 | Janus Aspen Series

Management of the Portfolio

Investment adviser

Janus Henderson Investors US LLC, 151 Detroit Street, Denver, Colorado 80206-4805, is the investment adviser to the Portfolio. The Adviser is responsible for the day-to-day management of the Portfolio’s investment portfolio and furnishes continuous advice and recommendations concerning the Portfolio’s investments. The Adviser also provides certain administration and other services and is responsible for other business affairs of the Portfolio. The Adviser utilizes a personnel-sharing arrangement with its foreign (non-U.S.) affiliates, Janus Henderson Investors UK Limited and Janus Henderson Investors (Jersey) Limited (collectively, “JHIUKL”), pursuant to which one or more Janus Henderson employees, acting for JHIUKL, may also serve as “associated persons” of the Adviser. In this capacity, such Janus Henderson employees, acting for JHIUKL, are subject to the oversight and supervision of the Adviser and may provide portfolio management, research, and related services to the Portfolio on behalf of the Adviser.

Management expenses

The following table reflects the Portfolio’s contractual investment advisory fee rate (expressed as an annual rate), as well as the actual compensation rate paid by the Portfolio to the Adviser after any applicable fee waivers and/or expense reimbursements. The rate shown is a fixed rate based on the Portfolio’s average daily net assets.

18 | Janus Aspen Series

Portfolio Name	Average Daily Net Assets of the Portfolio	Contractual Investment Advisory Fee (%) (annual rate)	Actual Compensation Rate Paid to Adviser (%) (for the fiscal year ended December 31, 2024)
Global Sustainable Equity Portfolio	First $2 Billion	0.75	0.00 (1)
	Over $2 Billion	0.70

(1)

For the fiscal year ended December 31, 2024, the Portfolio did not pay any compensation to the Adviser after any applicable fee waivers/expense reimbursements because the Portfolio’s fee waiver exceeded the investment advisory fee.

Expense Limitation

The Adviser has contractually agreed to waive the advisory fee payable by the Portfolio or reimburse expenses in an amount equal to the amount, if any, that the Portfolio’s total annual fund operating expenses, including the investment advisory fee, but excluding the fees payable pursuant to a Rule 12b-1 plan, shareholder servicing fees, out-of-pocket transfer agency/shareholder servicing costs, acquired fund fees and expenses, interest, dividends, taxes, brokerage commissions, and extraordinary expenses, exceed the annual rate shown below. Mortality risk, expense risk, and other charges imposed by participating insurance companies are also excluded from the expense limitation noted.

This contractual waiver may be modified or terminated only at the discretion of the Board of Trustees. For information about how the expense limit affects the total expenses of the Portfolio, if applicable, see the “Fees and Expenses of the Portfolio” table in the Portfolio Summary of the Prospectus. The Adviser has agreed to continue the waiver for at least a one-year period commencing on April 30, 2025.

Portfolio Name	Expense Limit Percentage (%)
Global Sustainable Equity Portfolio	0.68(1)

(1)

The previous expense limit (for the one-year period commencing April 29, 2024) was 0.80%.

Portfolio management

Global Sustainable Equity Portfolio

Co-Portfolio Managers Hamish Chamberlayne and Aaron Scully jointly share responsibility for the day-to-day management of the Portfolio, with no limitation on the authority of one co-portfolio manager in relation to the other.

Hamish Chamberlayne, CFA, is Head of Global Sustainable Equities of Janus Henderson Investors. He is Executive Vice President and Co-Portfolio Manager of Global Sustainable Equity Portfolio, which he has co-managed since inception in June 2020. He is also Portfolio Manager of other Janus Henderson accounts. Mr. Chamberlayne joined Henderson Global Investors Limited in 2007. He holds a Master’s degree in Chemistry from New College, Oxford University. Mr. Chamberlayne holds the Chartered Financial Analyst designation.

Aaron Scully, CFA, is Executive Vice President and Co-Portfolio Manager of Global Sustainable Equity Portfolio, which he has co-managed since inception in June 2020. He is also Portfolio Manager of other Janus Henderson accounts. Mr. Scully joined the Adviser in 2001 as a corporate financial analyst. He holds a Bachelor of Science degree in Finance from Indiana University. Mr. Scully holds the Chartered Financial Analyst designation.

Conflicts of Interest

19 | Janus Aspen Series

Other information

Classes of Shares

Closed Portfolio Policies

Liquidation/Reorganization of a Portfolio

DISTRIBUTION OF THE Portfolio

21 | Janus Aspen Series

Distributions and taxes

Distributions

Distribution Schedule

How Distributions Affect the Portfolio’s NAV

TAXES

Taxes on Distributions

Taxation of the Portfolio

22 | Janus Aspen Series

Shareholder’s guide

Pricing of portfolio shares

23 | Janus Aspen Series

Distribution, servicing, and administrative fees

Distribution and Shareholder Servicing Plan

Administrative Fees

Payments to financial intermediaries by the Adviser or its affiliates

24 | Janus Aspen Series

Purchases

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Refer to the prospectus of the appropriate insurance company separate account or your plan documents for information on how to invest in the Shares of the Portfolio. Under certain circumstances, the Portfolio may permit an in-kind purchase of Shares. Participating insurance companies and certain other designated organizations are authorized to receive purchase orders on the Portfolio’s behalf. As discussed under “Payments to Financial Intermediaries by the Adviser or its Affiliates,” the Adviser and its affiliates make payments to selected insurance companies, qualified plan service providers, or their affiliates, or other financial intermediaries that were instrumental in the acquisition or retention of accounts for the Portfolio or that provide services in connection with investments in the Portfolio. You should consider such arrangements when evaluating any recommendation of the Portfolio.

25 | Janus Aspen Series

Potential Conflicts

Redemptions

Large Shareholder Redemptions

Redemptions In-Kind

26 | Janus Aspen Series

Excessive trading

Excessive and Short-Term Trading Policies and Procedures

The Janus Henderson funds attempt to deter excessive trading through at least the following methods:

•

fair valuation of securities as described under “Pricing of Portfolio Shares”; and

•

trade monitoring.

The Portfolio’s Trustees may approve from time to time a redemption fee to be imposed by any Janus Henderson fund, subject to 60 days’ notice to shareholders of that fund.

The Portfolio’s policies and procedures regarding excessive trading may be modified at any time by the Portfolio’s Trustees.

27 | Janus Aspen Series

Excessive Trading Risks

Availability of Portfolio Holdings Information

•

Top Holdings. The Portfolio’s top portfolio holdings, in order of position size and as a percentage of the Portfolio’s total portfolio, are available monthly with a 15-day lag.

•

Other Information. The Portfolio may occasionally provide security breakdowns (e.g., industry, sector, regional, market capitalization, and asset allocation) and specific portfolio level performance attribution information and statistics monthly with a 15-day lag. Top/bottom equity securities ranked by performance attribution, including the percentage attribution to Portfolio performance, average Portfolio weighting, and other relevant data points, may be provided monthly with a 15-day lag.

28 | Janus Aspen Series

Financial highlights

The financial highlights table is intended to help you understand the Portfolio’s financial performance for the period ended December 31 of the fiscal periods shown. Items “Net asset value, beginning of period” through “Net asset value, end of period” reflect financial results for a single Portfolio Share. The gross expense ratio reflects expenses prior to any expense offset arrangement and waivers (reimbursements), if applicable. The net expense ratio reflects expenses after any expense offset arrangement and waivers (reimbursements), if applicable. The information shown for the fiscal periods ended December 31 has been audited by PricewaterhouseCoopers LLP, whose report, along with the Portfolio’s financial statements, is included in the Portfolio’s Form N-CSR and is incorporated by reference into the SAI.

The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in the Service Shares of the Portfolio (assuming reinvestment of all dividends and distributions) but do not include charges and expenses attributable to any insurance product. If these charges and expenses had been included, the performance for the periods shown would be lower. “Total return” information may include adjustments in accordance with generally accepted accounting principles. As a result, returns may differ from returns for shareholder transactions.

Global Sustainable Equity Portfolio – Service Shares

	Years ended December 31
	2024	2023	2022(1)
Net Asset Value, Beginning of Period	$10.44	$8.51	$10.00
Income/(Loss) from Investment Operations:
Net investment income/(loss)(2)	0.03	0.05	0.04
Net realized and unrealized gain/(loss)	1.12	1.93	(1.48)
Total from Investment Operations	1.15	1.98	(1.44)
Less Dividends and Distributions:
Dividends (from net investment income)	(0.03)	(0.05)	(0.05)
Distributions (from capital gains)	(0.07)	—	—
Total Dividends and Distributions	(0.10)	(0.05)	(0.05)
Net Asset Value, End of Period	$11.49	$10.44	$8.51
Total Return*	11.01%	23.24%	(14.44)%
Net Assets, End of Period (in thousands)	$4,519	$3,480	$2,265
Ratios to Average Net Assets**
Ratio of Gross Expenses	2.69%	4.31%	4.91%
Ratio of Net Expenses (After Waivers and Expense Offsets)	0.94%	0.92%	0.95%
Ratio of Net Investment Income/(Loss)	0.23%	0.57%	0.44%
Portfolio Turnover Rate	42%	17%	15%

*	Total return includes adjustments in accordance with generally accepted accounting principles required at the year or period end and are not annualized for periods of less than one full year. Total return does not include fees, charges, or expenses imposed by the variable annuity and life insurance contracts for which Janus Aspen Series serves as an underlying investment vehicle.
**	Annualized for periods of less than one full year.
(1)	Period from January 26, 2022 (inception date) through December 31, 2022.
(2)	Per share amounts are calculated based on average shares outstanding during the year or period.

30 | Janus Aspen Series

Glossary of investment terms

Equity and Debt Securities

Convertible securities are preferred stocks or bonds that pay a fixed dividend or interest payment and are convertible into common stock at a specified price or conversion ratio.

Rule 144A securities are securities that are not registered for sale to the general public under the Securities Act of 1933, as amended, but that may be resold to certain institutional investors.

31 | Janus Aspen Series

Futures, Options, and Other Derivatives

Other Investments, Strategies, and/or Techniques

Repatriation is the ability to move liquid financial assets from a foreign country to an investor’s country of origin.

32 | Janus Aspen Series

janushenderson.com/VIT

151 Detroit Street
Denver, CO 80206-4805
1-877-335-2687

The Trust’s Investment Company Act File No. is 811-7736.

This Prospectus describes Janus Henderson Global Technology and Innovation Portfolio (the “Portfolio”), a series of Janus Aspen Series (the “Trust”). Janus Henderson Investors US LLC (the “Adviser”) serves as investment adviser to the Portfolio. The Portfolio currently offers two classes of shares. The Service Shares (the “Shares”) are offered by this Prospectus in connection with investment in and payments under variable annuity contracts and variable life insurance contracts (collectively, “variable insurance contracts”), as well as certain qualified retirement plans.

For the purpose of this Prospectus, any reference to the “Janus Henderson funds” is inclusive of all series of the Trust, collectively, unless otherwise noted in this Prospectus.

Portfolio summary

Janus Henderson Global Technology and Innovation Portfolio

Ticker:

N/A

Service Shares

Investment Objective

Janus Henderson Global Technology and Innovation Portfolio (“Global Technology and Innovation Portfolio”) seeks long-term growth of capital.

Fees and Expenses of the Portfolio

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		0.64%
Distribution/Service (12b-1) Fees		0.25%
Other Expenses		0.08%
Total Annual Fund Operating Expenses		0.97%

EXAMPLE:

	1 Year	3 Years	5 Years	10 Years
Service Shares	$ 99	$ 309	$ 536	$ 1,190

Principal investment strategies

The Portfolio pursues its investment objective by investing, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in securities of companies that portfolio management believes will benefit significantly from advances or improvements in technology. These companies generally fall into two categories:

•

companies that portfolio management believes have or will develop products, processes, or services that will provide significant technological advancements or improvements; and

•

companies that portfolio management believes rely extensively on technology in connection with their operations or services.

Some of the industries and companies likely to be represented in the Portfolio’s holdings include e-commerce (companies doing business through the Internet); computer (hardware and software); communications (voice, data, and wireless); industrials; Internet (software, services, and infrastructure equipment); and media and entertainment.

2 | Janus Henderson Global Technology and Innovation Portfolio

The Portfolio implements this policy by investing primarily in equity securities of U.S. and foreign companies selected for their growth potential. The Portfolio typically invests at least 40% of its net assets in securities of issuers or companies that are economically tied to different countries throughout the world, excluding the United States. An issuer is deemed to be economically tied to a country or countries outside of the United States if one or more of the following tests are met: (i) the issuer is organized in, or its primary business office or principal trading market of its equity is located in, a country outside of the United States; (ii) a majority of the issuer’s revenues are derived from outside of the United States; or (iii) a majority of the issuer’s assets are located outside of the United States. The Portfolio may have exposure to emerging markets. From time to time, the Portfolio may invest in shares of companies through initial public offerings.

The Portfolio has a fundamental policy to invest 25% or more of the value of its total assets in the industries within the information technology sector in the aggregate.

The Portfolio is classified as nondiversified, which allows it to hold larger positions in more securities compared to a portfolio that is classified as diversified.

Portfolio management applies a “bottom-up” approach in choosing investments. In other words, portfolio management looks at companies one at a time to determine if a company is an attractive investment opportunity and if it is consistent with the Portfolio’s investment policies. Factors that portfolio management may consider in its fundamental analysis include the strength of a company’s balance sheet and a company’s projected returns or growth rates. Portfolio management will generally consider selling a position when, among other things, the investment thesis for owning a position has changed or if the position exceeds its targeted value.

Principal investment risks

3 | Janus Henderson Global Technology and Innovation Portfolio

stocks tend to shift in and out of favor depending on market and economic conditions, “growth” stocks may perform differently from other types of securities and the market as a whole.

Industry and Sector Risk. The Portfolio may have a significant portion of its assets invested in securities of companies conducting similar business or businesses within the same industries. Companies in the same industry or economic sector may be similarly affected by negative economic or market events, making the Portfolio more vulnerable to unfavorable developments than portfolios that invest more broadly. As the Portfolio’s holdings become more concentrated, the Portfolio is less able to spread risk and potentially reduce the risk of loss and volatility.

•

Semiconductor Industry Risk. Semiconductor companies may have limited product lines, markets, financial resources or personnel. Semiconductor companies typically face intense competition, potentially rapid product obsolescence and high capital costs and are dependent on third-party suppliers and the availability of materials. They are also heavily dependent on intellectual property rights and may be adversely affected by loss or impairment of those rights. Semiconductor companies are also affected by the economic performance of their customers.

•

Software Industry Risk. Software companies can be significantly affected by intense competition, aggressive pricing, technological innovation, product obsolescence, and the ability to attract and retain skilled employees. Software companies also may be dependent on intellectual property rights and may be adversely affected by loss or impairment of those rights.

Initial Public Offering Risk. The Portfolio’s purchase of shares issued in an initial public offering (“IPO”) exposes it to the risks associated with companies that have little operating history as public companies, as well as to the risks inherent in those sectors of the market where these new issuers operate. There can be no assurance that the Portfolio will identify favorable IPO investment opportunities.

4 | Janus Henderson Global Technology and Innovation Portfolio

including financial information, may be less available or reliable and the Adviser’s ability to conduct due diligence with respect to such companies may be limited. Accordingly, these investments may be potentially more volatile in price and less liquid than investments in developed securities markets, resulting in greater risk to investors. There is a risk in developing countries that a current or future economic or political crisis could lead to price controls, forced mergers of companies, expropriation or confiscatory taxation, imposition or enforcement of foreign ownership limits, seizure, nationalization, sanctions or imposition of restrictions by various governmental entities on investment and trading, or creation of government monopolies, any of which may have a detrimental effect on the Portfolio’s investments. In addition, the taxation systems at the federal, regional, and local levels in developing or emerging market countries may be less transparent, inconsistently enforced, and subject to change. Emerging markets may be subject to a higher degree of corruption and fraud than developed markets, and financial institutions and transaction counterparties may have less financial sophistication, creditworthiness, and/or resources than participants in developed markets.

An investment in the Portfolio is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance information

Annual Total Returns for Service Shares (calendar year-end)

Best Quarter:

2nd Quarter 2020

32.98%

Worst Quarter:

2nd Quarter 2022

– 26.02%

5 | Janus Henderson Global Technology and Innovation Portfolio

Average Annual Total Returns (periods ended 12/31/24)
	1 Year	5 Years	10 Years
Global Technology and Innovation Portfolio
Service Shares	31.76%	17.80%	19.06%
S&P 500® Index (reflects no deduction for fees, expenses, or taxes)	25.02%	14.53%	13.10%
MSCI All Country World Information Technology Index (reflects no deduction for fees, expenses, or taxes, except foreign withholding taxes)	31.59%	20.50%	19.16%

The Portfolio’s broad-based benchmark index is the S&P 500 Index. The Portfolio’s additional benchmark index is the MSCI All Country World Information Technology Index. The indices are described below.

•

The S&P 500 Index is a commonly recognized, market capitalization-weighted index of 500 widely held equity securities, designed to measure broad U.S. equity performance.

•

The MSCI All Country World Information Technology Index is a capitalization-weighted index that measures the performance of information technology securities from developed market countries and emerging market countries.

Management

Investment Adviser: Janus Henderson Investors US LLC

Portfolio Management: Jonathan Cofsky, CFA, is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since March 2022. Denny Fish is Executive Vice President and Lead Portfolio Manager of the Portfolio, which he has managed or co-managed since January 2016.

Purchase and sale of Portfolio shares

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Redemptions, like purchases, may be effected only through the separate accounts of participating insurance companies or through qualified retirement plans. Requests are duly processed at the net asset value next calculated after an order is received in good order by the Portfolio or its agents. Refer to the appropriate separate account prospectus or plan documents for details.

Tax information

Payments to Insurers, Broker-Dealers, and other financial intermediaries

6 | Janus Henderson Global Technology and Innovation Portfolio

Additional information about the Portfolio

Fees and expenses

•

“Other Expenses”

•

Additional investment strategies and general portfolio policies

The Portfolio’s Board of Trustees (“Trustees”) may change the Portfolio’s investment objective or non-fundamental principal investment strategies without a shareholder vote. The Portfolio will notify you in writing at least 60 days before making any such change it considers material. In addition, the Portfolio will provide shareholders with at least 60 days’ notice prior to changing the 80% investment policy. If there is a material change to the Portfolio’s investment objective or principal investment strategies, you should consider whether the Portfolio remains an appropriate investment for you. There is no guarantee that the Portfolio will achieve its investment objective.

7 | Janus Aspen Series

not be required to dispose of any securities. The “Glossary of Investment Terms” includes descriptions of investment terms used throughout the Prospectus.

Security Selection

Cash Position

Emerging Markets

The Portfolio may invest in securities of issuers or companies from or with exposure to one or more “developing countries” or “emerging market countries.” Such countries include, but are not limited to, countries included in the MSCI Emerging Markets IndexSM. Emerging market countries in which the Portfolio may invest include frontier market countries, the economies of which are less developed than other emerging market countries. Frontier market countries typically are located in the Asia-Pacific region, Central and Eastern Europe, the Middle East, Central and South America, and Africa.

ESG Integration

Illiquid Investments

8 | Janus Aspen Series

Initial Public Offerings and Secondary Offerings

Leverage

Nondiversification

Portfolio Turnover

REITs and Real Estate-Related Securities

9 | Janus Aspen Series

have not elected (or are not eligible) to be taxed as a REIT. The reasons for not making such an election include the (i) availability of tax-loss carry-forwards, (ii) operation in non-REIT-qualifying lines of business, and (iii) ability to retain earnings. Instead, REOCs are generally structured as “C” corporations under the Internal Revenue Code of 1986, as amended, and, as a result, are not required to distribute any portion of their income. In this regard, although REOCs do not receive the same favorable tax treatment that is accorded to REITs, REOCs are typically subject to fewer restrictions than REITs, including the ability to retain and/or reinvest funds from operations and more flexibility in terms of the real estate investments they can make.

Securities Lending

Short Sales

10 | Janus Aspen Series

Special Situations

Other Types of Investments

•

debt securities (such as bonds, notes, sovereign debt, and debentures)

•

preferred stocks and securities convertible into common stocks or preferred stocks

•

indexed/structured securities (such as commercial and residential mortgage- and asset-backed securities)

•

securities purchased on a when-issued, delayed delivery, or forward commitment basis

•

equity and fixed-income securities issued in private placement transactions

Risks of the Portfolio

11 | Janus Aspen Series

that the Portfolio focuses its transactions with a limited number of counterparties, it will have greater exposure to the risks associated with one or more counterparties.

12 | Janus Aspen Series

foreign and emerging market governments, may involve greater risks than investing in domestic securities because the Portfolio’s performance may depend on factors other than the performance of a particular company. These factors include:

•

Transaction Costs Risk. Costs of buying, selling, and holding foreign securities, including brokerage, tax, and custody costs, may be higher than those involved in domestic transactions.

•

13 | Janus Aspen Series

an accelerated rate, and these companies may be subject to short product cycles and aggressive pricing, which may increase their volatility.

•

14 | Janus Aspen Series

•

15 | Janus Aspen Series

same factors that adversely affect REIT investments; however, REOCs may also be adversely affected by income streams derived from businesses other than real estate ownership.

16 | Janus Aspen Series

Management of the Portfolio

Investment adviser

Management expenses

The following table reflects the Portfolio’s contractual investment advisory fee rate (expressed as an annual rate), as well as the actual compensation rate paid by the Portfolio to the Adviser after any applicable fee waivers and/or expense reimbursements. The rate shown is a fixed rate based on the Portfolio’s average daily net assets.

17 | Janus Aspen Series

Portfolio Name	Average Daily Net Assets of the Portfolio	Contractual Investment Advisory Fee (%) (annual rate)	Actual Compensation Rate Paid to Adviser (%) (for the fiscal year ended December 31, 2024)
Global Technology and Innovation Portfolio	All Asset Levels	0.64	0.64

Expense Limitation

Portfolio Name	Expense Limit Percentage (%)
Global Technology and Innovation Portfolio	0.88(1)

(1)

The previous expense limit (for the one-year period commencing April 29, 2024) was 0.95%.

Portfolio management

Global Technology and Innovation Portfolio

Co-Portfolio Managers Jonathan Cofsky and Denny Fish are responsible for the day-to-day management of the Portfolio. Mr. Fish, as Lead Portfolio Manager, has the authority to exercise final decision-making on the Portfolio.

Jonathan Cofsky, CFA, is Executive Vice President and Co-Portfolio Manager of Global Technology and Innovation Portfolio, which he has co-managed since March 2022. Mr. Cofsky is also Portfolio Manager of other Janus Henderson accounts and performs duties as an analyst. He joined the Adviser in 2014. Mr. Cofsky holds a Bachelor of Arts degree in Economics from Dartmouth College. He holds the Chartered Financial Analyst designation.

Denny Fish is Head of the Technology Sector Team at Janus Henderson Investors. He is Executive Vice President and Lead Portfolio Manager of Global Technology and Innovation Portfolio, which he has managed or co-managed since January 2016. Mr. Fish is also Portfolio Manager of other Janus Henderson accounts. He holds a Bachelor of Science degree in Civil Engineering from the University of Illinois and a Master of Business Administration degree from the University of Southern California Marshall School.

Conflicts of Interest

18 | Janus Aspen Series

Other information

Classes of Shares

Closed Portfolio Policies

Liquidation/Reorganization of a Portfolio

DISTRIBUTION OF THE Portfolio

20 | Janus Aspen Series

Distributions and taxes

Distributions

Distribution Schedule

How Distributions Affect the Portfolio’s NAV

TAXES

Taxes on Distributions

Taxation of the Portfolio

21 | Janus Aspen Series

Shareholder’s guide

Pricing of portfolio shares

22 | Janus Aspen Series

Distribution, servicing, and administrative fees

Distribution and Shareholder Servicing Plan

Administrative Fees

Payments to financial intermediaries by the Adviser or its affiliates

23 | Janus Aspen Series

Purchases

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Refer to the prospectus of the appropriate insurance company separate account or your plan documents for information on how to invest in the Shares of the Portfolio. Under certain circumstances, the Portfolio may permit an in-kind purchase of Shares. Participating insurance companies and certain other designated organizations are authorized to receive purchase orders on the Portfolio’s behalf. As discussed under “Payments to Financial Intermediaries by the Adviser or its Affiliates,” the Adviser and its affiliates make payments to selected insurance companies, qualified plan service providers, or their affiliates, or other financial intermediaries that were instrumental in the acquisition or retention of accounts for the Portfolio or that provide services in connection with investments in the Portfolio. You should consider such arrangements when evaluating any recommendation of the Portfolio.

24 | Janus Aspen Series

Potential Conflicts

Redemptions

Large Shareholder Redemptions

Redemptions In-Kind

25 | Janus Aspen Series

Excessive trading

Excessive and Short-Term Trading Policies and Procedures

The Janus Henderson funds attempt to deter excessive trading through at least the following methods:

•

fair valuation of securities as described under “Pricing of Portfolio Shares”; and

•

trade monitoring.

The Portfolio’s Trustees may approve from time to time a redemption fee to be imposed by any Janus Henderson fund, subject to 60 days’ notice to shareholders of that fund.

The Portfolio’s policies and procedures regarding excessive trading may be modified at any time by the Portfolio’s Trustees.

26 | Janus Aspen Series

Excessive Trading Risks

Availability of Portfolio Holdings Information

•

Top Holdings. The Portfolio’s top portfolio holdings, in order of position size and as a percentage of the Portfolio’s total portfolio, are available monthly with a 15-day lag.

•

Other Information. The Portfolio may occasionally provide security breakdowns (e.g., industry, sector, regional, market capitalization, and asset allocation) and specific portfolio level performance attribution information and statistics monthly with a 15-day lag. Top/bottom equity securities ranked by performance attribution, including the percentage attribution to Portfolio performance, average Portfolio weighting, and other relevant data points, may be provided monthly with a 15-day lag.

27 | Janus Aspen Series

Financial highlights

Global Technology and Innovation Portfolio – Service Shares

	Years ended December 31
	2024	2023	2022	2021	2020
Net Asset Value, Beginning of Period	$16.06	$10.41	$20.91	$20.51	$15.03
Income/(Loss) from Investment Operations:
Net investment income/(loss)(1)	(0.06)	(0.04)	(0.05)	(0.10)	(0.05)
Net realized and unrealized gain/(loss)	5.16	5.69	(7.66)	3.49	7.10
Total from Investment Operations	5.10	5.65	(7.71)	3.39	7.05
Less Dividends and Distributions:
Dividends (from net investment income)	—	—	—	(0.03)	—
Distributions (from capital gains)	—	—	(2.79)	(2.96)	(1.57)
Total Dividends and Distributions	—	—	(2.79)	(2.99)	(1.57)
Net Asset Value, End of Period	$21.16	$16.06	$10.41	$20.91	$20.51
Total Return*	31.76%	54.27%	(37.12)%	17.69%	50.80%
Net Assets, End of Period (in thousands)	$1,092,666	$853,134	$535,573	$878,244	$732,854
Ratios to Average Net Assets
Ratio of Gross Expenses	0.97%	0.97%	0.97%	0.97%	0.99%
Ratio of Net Expenses (After Waivers and Expense Offsets)	0.97%	0.97%	0.97%	0.97%	0.99%
Ratio of Net Investment Income/(Loss)	(0.32)%	(0.26)%	(0.38)%	(0.49)%	(0.32)%
Portfolio Turnover Rate	35%	41%	43%	47%	44%

*	Total return includes adjustments in accordance with generally accepted accounting principles required at the year or period end and are not annualized for periods of less than one full year. Total return does not include fees, charges, or expenses imposed by the variable annuity and life insurance contracts for which Janus Aspen Series serves as an underlying investment vehicle.
(1)	Per share amounts are calculated based on average shares outstanding during the year or period.

29 | Janus Aspen Series

Glossary of investment terms

Equity and Debt Securities

Convertible securities are preferred stocks or bonds that pay a fixed dividend or interest payment and are convertible into common stock at a specified price or conversion ratio.

30 | Janus Aspen Series

Rule 144A securities are securities that are not registered for sale to the general public under the Securities Act of 1933, as amended, but that may be resold to certain institutional investors.

Futures, Options, and Other Derivatives

Equity swaps involve the exchange by two parties of future cash flow (e.g., one cash flow based on a referenced interest rate and the other based on the performance of stock or a stock index).

31 | Janus Aspen Series

Other Investments, Strategies, and/or Techniques

Repatriation is the ability to move liquid financial assets from a foreign country to an investor’s country of origin.

32 | Janus Aspen Series

janushenderson.com/VIT

151 Detroit Street
Denver, CO 80206-4805
1-877-335-2687

The Trust’s Investment Company Act File No. is 811-7736.

This Prospectus describes Janus Henderson Mid Cap Value Portfolio (the “Portfolio”), a series of Janus Aspen Series (the “Trust”). Janus Henderson Investors US LLC (the “Adviser”) serves as investment adviser to the Portfolio. The Portfolio currently offers two classes of shares. The Service Shares (the “Shares”) are offered by this Prospectus in connection with investment in and payments under variable annuity contracts and variable life insurance contracts (collectively, “variable insurance contracts”), as well as certain qualified retirement plans.

For the purpose of this Prospectus, any reference to the “Janus Henderson funds” is inclusive of all series of the Trust, collectively, unless otherwise noted in this Prospectus.

Portfolio summary

Janus Henderson Mid Cap Value Portfolio

Ticker:

N/A

Service Shares

Investment Objective

Janus Henderson Mid Cap Value Portfolio (“Mid Cap Value Portfolio”) seeks capital appreciation.

Fees and Expenses of the Portfolio

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Management Fees(1)		0.75%
Distribution/Service (12b-1) Fees		0.25%
Other Expenses		0.18%
Total Annual Fund Operating Expenses		1.18%

(1)

EXAMPLE:

	1 Year	3 Years	5 Years	10 Years
Service Shares	$ 120	$ 375	$ 649	$ 1,432

Principal investment strategies

The Portfolio pursues its investment objective by investing primarily in the common stocks of mid-sized companies and focuses on companies whose stock prices are believed to be undervalued by portfolio management or that have fallen out of favor with the market. The Portfolio invests, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities of companies whose market capitalization falls, at the time of purchase, within the capitalization range of the Russell Midcap® Value Index. The market capitalizations within the index will vary, but as of December 31, 2024, they ranged from approximately $205 million to $69.66 billion. From time to time, the Portfolio may invest in shares of companies through initial public offerings. The Portfolio may also invest in foreign securities, as well as in real estate investment trusts (“REITs”) and similar REIT-like entities.

As defensive value managers, portfolio management generally looks for companies with:

•

strong management teams;

•

strong and stable balance sheets and solid recurring free cash flows;

2 | Janus Henderson Mid Cap Value Portfolio

•

attractive relative and absolute valuation ratios or that have underperformed recently;

•

favorable reward to risk characteristics;

•

sustainable competitive advantages that are trading at attractive valuations; and

•

strong long-term prospects.

Portfolio management’s philosophy is to weigh a security’s downside risk before considering its upside potential, which may help provide an element of capital preservation.

Principal investment risks

Value Investing Risk. Because different types of stocks tend to shift in and out of favor depending on market and economic conditions, “value” stocks may perform differently than other types of stocks and from the market as a whole, and can continue to be undervalued by the market for long periods of time. It is also possible that a value stock will never appreciate to the extent expected.

3 | Janus Henderson Mid Cap Value Portfolio

and appeal to purchasers. In addition, a REIT could fail to qualify for tax-free pass-through of its income under the Internal Revenue Code of 1986, as amended, or fail to maintain its exemption from registration under the Investment Company Act of 1940, as amended, which could produce adverse economic consequences for the REIT and its investors, including the Portfolio. Dividends received by the Portfolio from a REIT generally will not constitute qualified dividend income.

An investment in the Portfolio is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance information

Annual Total Returns for Service Shares (calendar year-end)

Best Quarter:

4th Quarter 2020

18.15%

Worst Quarter:

1st Quarter 2020

– 29.16%

4 | Janus Henderson Mid Cap Value Portfolio

Average Annual Total Returns (periods ended 12/31/24)
	1 Year	5 Years	10 Years
Mid Cap Value Portfolio
Service Shares	12.80%	6.86%	7.33%
Russell 3000® Index (reflects no deduction for fees, expenses, or taxes)	23.81%	13.86%	12.55%
Russell Midcap® Value Index (reflects no deduction for fees, expenses, or taxes)	13.07%	8.59%	8.10%

Effective February 25, 2025, the Portfolio changed its broad-based securities market index from the Russell Midcap Value Index to the Russell 3000 Index due to regulatory requirements. The Portfolio retained the Russell Midcap Value Index as a performance benchmark because the Russell Midcap Value Index is more closely aligned with the Portfolio’s investment strategies and investment restrictions. The indices are described below.

•

The Russell 3000 Index measures the performance of the largest 3000 U.S. companies.

•

The Russell Midcap Value Index measures the performance of those Russell Midcap companies with lower price-to-book ratios and lower forecasted growth values.

Management

Investment Adviser: Janus Henderson Investors US LLC

Portfolio Management: Kevin Preloger is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since April 2013. Justin Tugman, CFA, is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since March 2015.

Purchase and sale of Portfolio shares

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Redemptions, like purchases, may be effected only through the separate accounts of participating insurance companies or through qualified retirement plans. Requests are duly processed at the net asset value next calculated after an order is received in good order by the Portfolio or its agents. Refer to the appropriate separate account prospectus or plan documents for details.

Tax information

Payments to Insurers, Broker-Dealers, and other financial intermediaries

5 | Janus Henderson Mid Cap Value Portfolio

Additional information about the Portfolio

Fees and expenses

•

The “Management Fee” is the investment advisory fee rate paid by the Portfolio to the Adviser. Mid Cap Value Portfolio pays an investment advisory fee rate that adjusts up or down by a variable rate of up to 0.15% (assuming constant assets) on a monthly basis based upon the Portfolio’s performance relative to its benchmark index during a measurement period. This base fee rate, prior to any performance adjustment, is 0.64%. Refer to “Management Expenses” in this Prospectus for additional information with further description in the Statement of Additional Information (“SAI”).

•

“Other Expenses”

•

The Adviser has contractually agreed to waive and/or reimburse the Portfolio’s “Total Annual Fund Operating Expenses” to a certain limit for at least a one-year period commencing on April 30, 2025. The expense limit is described in the “Management Expenses” section of this Prospectus. Because a fee waiver and/or reimbursement will have a positive effect upon a portfolio’s performance, a portfolio that pays a performance-based investment advisory fee may experience a performance adjustment that is considered favorable to the Adviser as a result of a fee waiver and/or reimbursement that is in place during the period when the performance adjustment applies.

•

Additional investment strategies and general portfolio policies

The Portfolio’s Board of Trustees (“Trustees”) may change the Portfolio’s investment objective or non-fundamental principal investment strategies without a shareholder vote. The Portfolio will notify you in writing at least 60 days before making any such change it considers material. In addition, the Portfolio will provide shareholders with at least 60 days’ notice prior to changing the 80% investment policy. If there is a material change to the Portfolio’s investment objective or principal investment strategies, you should consider whether the Portfolio remains an appropriate investment for you. There is no guarantee that the Portfolio will achieve its investment objective.

6 | Janus Aspen Series

use to a lesser extent. These non-principal investment strategies and policies may become more important in the future since the Portfolio’s composition can change over time. Except for the Portfolio’s policies with respect to illiquid investments, borrowing, and derivatives use, the percentage limitations included in these policies and elsewhere in this Prospectus and/or the SAI normally apply only at the time of purchase of a security. So, for example, if the Portfolio exceeds a limit, other than illiquid investments, borrowing, and derivatives use, as a result of market fluctuations or the sale of other securities, it will not be required to dispose of any securities. The “Glossary of Investment Terms” includes descriptions of investment terms used throughout the Prospectus.

Security Selection

•

strong management teams;

•

strong and stable balance sheets and solid recurring free cash flows;

•

attractive relative and absolute valuation ratios or that have underperformed recently;

•

favorable reward to risk characteristics;

•

sustainable competitive advantages that are trading at attractive valuations; and

•

strong long-term prospects.

Cash Position

Emerging Markets

ESG Integration

7 | Janus Aspen Series

may not be considered for every investment decision. Portfolio management may assess the relevance of ESG Factors to its fundamental research process differently across issuers, sectors, regions, and asset classes.

Foreign Securities

Illiquid Investments

Initial Public Offerings and Secondary Offerings

Portfolio Turnover

Securities Lending

A portfolio may seek to earn additional income through lending its securities to certain qualified broker-dealers and institutions in an amount equal to up to one-third of its total assets as determined at the time of the loan origination. When a portfolio lends its securities, it receives collateral (including cash collateral), at least equal to the value of securities loaned. The portfolio may earn income by investing this collateral in one or more affiliated or non-affiliated cash management vehicles. It is also possible that, due to a decline in the value of a cash management vehicle in which collateral is invested, the portfolio may lose money. There is also the risk that when portfolio securities are lent, the securities may not be returned on a timely basis, and the portfolio may experience delays and costs in recovering the security or gaining access to the collateral provided to the portfolio to collateralize the loan. If the portfolio is unable to recover a security on loan, the portfolio may use the collateral to purchase a replacement security in the market. There is a risk that the value of the collateral could be insufficient to cover the cost of the replacement security resulting in a loss to the portfolio. In certain circumstances, individual loan transactions could yield negative returns. The Adviser intends to manage a portion of the cash collateral in an affiliated cash management vehicle and will receive an investment advisory fee for managing such assets.

8 | Janus Aspen Series

Short Sales

Special Situations

Other Types of Investments

•

debt securities (such as bonds, notes, sovereign debt, and debentures)

•

preferred stocks and securities convertible into common stocks or preferred stocks

9 | Janus Aspen Series

•

indexed/structured securities (such as commercial and residential mortgage- and asset-backed securities)

•

securities purchased on a when-issued, delayed delivery, or forward commitment basis

•

equity and fixed-income securities issued in private placement transactions

Risks of the Portfolio

Emerging Markets Risk. To the extent that the Portfolio invests a significant amount of its assets in one or more of these countries, its returns and net asset value may be affected to a large degree by events and economic conditions in such countries. The risks of foreign investing are heightened when investing in emerging markets, which may result in the price of investments in emerging markets experiencing sudden and sharp price swings. In many developing markets, there is less government supervision and regulation of stock exchanges, brokers, and listed companies than in more developed markets, making these investments potentially more volatile in price and less liquid than investments in developed securities markets, resulting in greater risk to investors. There is a risk in developing countries that a current or future economic or political crisis could lead to price controls, forced mergers of companies, expropriation or confiscatory taxation, imposition or enforcement of foreign ownership limits, seizure, nationalization, sanctions or imposition of restrictions by various governmental entities on investment and trading, or creation of government monopolies, any of which may have a detrimental effect on the Portfolio’s investments.

10 | Janus Aspen Series

•

11 | Janus Aspen Series

•

Transaction Costs Risk. Costs of buying, selling, and holding foreign securities, including brokerage, tax, and custody costs, may be higher than those involved in domestic transactions.

12 | Janus Aspen Series

•

13 | Janus Aspen Series

14 | Janus Aspen Series

Management of the Portfolio

Investment adviser

Management expenses

Mid Cap Value Portfolio pays an investment advisory fee rate that may adjust up or down based on the Portfolio’s performance relative to the cumulative investment record of its performance fee benchmark index (referred to in this section as the “benchmark index”), the Russell Midcap Value Index, over a rolling 36-month performance measurement period.

The table below reflects the Portfolio’s base fee rate (expressed as an annual rate), as well as the actual compensation rate paid by the Portfolio to the Adviser after any applicable fee waivers and/or expense reimbursements. The third column shows the full performance rate for outperformance or underperformance during the measurement period relative to the Portfolio’s benchmark index. The fourth column shows the performance adjusted investment advisory fee rate, which is equal to the Portfolio’s base fee rate plus or minus the performance adjustment over the period without any fee waivers. This fourth

15 | Janus Aspen Series

column shows the actual compensation rate paid by the Portfolio after any applicable fee waivers and/or expense reimbursements as of the end of the fiscal year.

Portfolio Name	Base Fee Rate (%)	Full Performance Rate vs. Benchmark Index	Performance Adjusted Investment Advisory Fee Rate/ Actual Compensation Rate Paid to Adviser (%) (for the fiscal year ended December 31, 2024)
Mid Cap Value Portfolio	0.64	±4.00%	0.75

The calculation of the performance adjustment applies as follows:

Investment Advisory Fee = Base Fee Rate +/– Performance Adjustment

The application of an expense limit, if any, will have a positive effect upon Mid Cap Value Portfolio’s performance and may result in an increase in the Performance Adjustment. It is possible that the cumulative dollar amount of additional compensation ultimately payable to the Adviser may, under some circumstances, exceed the cumulative dollar amount of management fees waived by the Adviser.

16 | Janus Aspen Series

The investment performance of the Portfolio’s Service Shares for the performance measurement period is used to calculate the Performance Adjustment. After the Adviser determines whether the Portfolio’s performance was above or below its benchmark index by comparing the investment performance of the Portfolio’s Service Shares against the cumulative investment record of the Portfolio’s benchmark index, the Adviser applies the same Performance Adjustment (positive or negative) across each other class of shares of the Portfolio, as applicable. It is not possible to predict the effect of the Performance Adjustment on future overall compensation to the Adviser since it depends on the performance of the Portfolio relative to the record of the Portfolio’s benchmark index and future changes to the size of the Portfolio.

Expense Limitation

The Adviser has contractually agreed to waive the advisory fee payable by the Portfolio or reimburse expenses in an amount equal to the amount, if any, that the Portfolio’s total annual fund operating expenses, including the investment advisory fee, but excluding any performance adjustments to management fees, the fees payable pursuant to a Rule 12b-1 plan, shareholder servicing fees, out-of-pocket transfer agency/shareholder servicing costs, acquired fund fees and expenses, interest, dividends, taxes, brokerage commissions, and extraordinary expenses, exceed the annual rate shown below. Mortality risk, expense risk, and other charges imposed by participating insurance companies are also excluded from the expense limitation noted.

Portfolio Name	Expense Limit Percentage (%)
Mid Cap Value Portfolio(1)	0.77

(1)

The Portfolio pays an investment advisory fee rate that may adjust up or down based on the Portfolio’s performance relative to its benchmark index during a measurement period. Because a fee waiver and/or reimbursement will have a positive effect upon the Portfolio’s performance, a fee waiver and/or reimbursement that is in place during the period when the performance adjustment applies may affect the performance adjustment in a way that is favorable to the Adviser.

Portfolio management

Mid Cap Value Portfolio

Co-Portfolio Managers Kevin Preloger and Justin Tugman are responsible for the day-to-day management of the Portfolio, with no limitation on the authority of one co-portfolio manager in relation to the other.

Kevin Preloger is Executive Vice President and Co-Portfolio Manager of Mid Cap Value Portfolio, which he has co-managed since April 2013. Mr. Preloger is also Portfolio Manager of other Janus Henderson accounts. He holds a Bachelor of Arts degree in Economics from Northwestern University.

Justin Tugman, CFA, is Executive Vice President and Co-Portfolio Manager of Mid Cap Value Portfolio, which he has co-managed since March 2015. Mr. Tugman is also Portfolio Manager of other Janus Henderson accounts. He holds a Bachelor of Science degree in Finance from the University of Wyoming and a Master of Business Administration degree from Tulane University. Mr. Tugman holds the Chartered Financial Analyst designation.

Conflicts of Interest

17 | Janus Aspen Series

Other information

Classes of Shares

Closed Portfolio Policies

Liquidation/Reorganization of a Portfolio

DISTRIBUTION OF THE Portfolio

19 | Janus Aspen Series

Distributions and taxes

Distributions

Distribution Schedule

How Distributions Affect the Portfolio’s NAV

TAXES

Taxes on Distributions

Taxation of the Portfolio

20 | Janus Aspen Series

Shareholder’s guide

Pricing of portfolio shares

21 | Janus Aspen Series

Distribution, servicing, and administrative fees

Distribution and Shareholder Servicing Plan

Administrative Fees

Payments to financial intermediaries by the Adviser or its affiliates

22 | Janus Aspen Series

Purchases

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Refer to the prospectus of the appropriate insurance company separate account or your plan documents for information on how to invest in the Shares of the Portfolio. Under certain circumstances, the Portfolio may permit an in-kind purchase of Shares. Participating insurance companies and certain other designated organizations are authorized to receive purchase orders on the Portfolio’s behalf. As discussed under “Payments to Financial Intermediaries by the Adviser or its Affiliates,” the Adviser and its affiliates make payments to selected insurance companies, qualified plan service providers, or their affiliates, or other financial intermediaries that were instrumental in the acquisition or retention of accounts for the Portfolio or that provide services in connection with investments in the Portfolio. You should consider such arrangements when evaluating any recommendation of the Portfolio.

23 | Janus Aspen Series

Potential Conflicts

Redemptions

Large Shareholder Redemptions

Redemptions In-Kind

24 | Janus Aspen Series

Excessive trading

Excessive and Short-Term Trading Policies and Procedures

The Janus Henderson funds attempt to deter excessive trading through at least the following methods:

•

fair valuation of securities as described under “Pricing of Portfolio Shares”; and

•

trade monitoring.

The Portfolio’s Trustees may approve from time to time a redemption fee to be imposed by any Janus Henderson fund, subject to 60 days’ notice to shareholders of that fund.

The Portfolio’s policies and procedures regarding excessive trading may be modified at any time by the Portfolio’s Trustees.

25 | Janus Aspen Series

Excessive Trading Risks

Availability of Portfolio Holdings Information

•

Top Holdings. The Portfolio’s top portfolio holdings, in order of position size and as a percentage of the Portfolio’s total portfolio, are available monthly with a 15-day lag.

•

Other Information. The Portfolio may occasionally provide security breakdowns (e.g., industry, sector, regional, market capitalization, and asset allocation) and specific portfolio level performance attribution information and statistics monthly with a 15-day lag. Top/bottom equity securities ranked by performance attribution, including the percentage attribution to Portfolio performance, average Portfolio weighting, and other relevant data points, may be provided monthly with a 15-day lag.

26 | Janus Aspen Series

Financial highlights

Mid Cap Value Portfolio – Service Shares

	Years ended December 31
	2024	2023	2022	2021	2020
Net Asset Value, Beginning of Period	$16.72	$15.64	$18.36	$15.42	$16.12
Income/(Loss) from Investment Operations:
Net investment income/(loss)(1)	0.12	0.14	0.14	0.12	0.13
Net realized and unrealized gain/(loss)	1.95	1.55	(1.30)	2.87	(0.40)
Total from Investment Operations	2.07	1.69	(1.16)	2.99	(0.27)
Less Dividends and Distributions:
Dividends (from net investment income)	(0.15)	(0.15)	(0.19)	(0.05)	(0.15)
Distributions (from capital gains)	(0.96)	(0.46)	(1.37)	—	(0.28)
Total Dividends and Distributions	(1.11)	(0.61)	(1.56)	(0.05)	(0.43)
Net Asset Value, End of Period	$17.68	$16.72	$15.64	$18.36	$15.42
Total Return*	12.80%	11.11%	(5.77)%	19.42%	(1.21)%
Net Assets, End of Period (in thousands)	$58,443	$60,036	$66,344	$78,435	$67,967
Ratios to Average Net Assets
Ratio of Gross Expenses	1.18%	0.93%	0.91%	0.92%	1.06%
Ratio of Net Expenses (After Waivers and Expense Offsets)	1.18%	0.93%	0.91%	0.92%	1.06%
Ratio of Net Investment Income/(Loss)	0.66%	0.91%	0.86%	0.68%	0.97%
Portfolio Turnover Rate	42%	47%	48%	63%	44%

*	Total return includes adjustments in accordance with generally accepted accounting principles required at the year or period end and are not annualized for periods of less than one full year. Total return does not include fees, charges, or expenses imposed by the variable annuity and life insurance contracts for which Janus Aspen Series serves as an underlying investment vehicle.
(1)	Per share amounts are calculated based on average shares outstanding during the year or period.

28 | Janus Aspen Series

Glossary of investment terms

Equity and Debt Securities

Convertible securities are preferred stocks or bonds that pay a fixed dividend or interest payment and are convertible into common stock at a specified price or conversion ratio.

29 | Janus Aspen Series

Rule 144A securities are securities that are not registered for sale to the general public under the Securities Act of 1933, as amended, but that may be resold to certain institutional investors.

Futures, Options, and Other Derivatives

Other Investments, Strategies, and/or Techniques

30 | Janus Aspen Series

Repatriation is the ability to move liquid financial assets from a foreign country to an investor’s country of origin.

31 | Janus Aspen Series

janushenderson.com/VIT

151 Detroit Street
Denver, CO 80206-4805
1-877-335-2687

The Trust’s Investment Company Act File No. is 811-7736.

This Prospectus describes Janus Henderson Overseas Portfolio (the “Portfolio”), a series of Janus Aspen Series (the “Trust”). Janus Henderson Investors US LLC (the “Adviser”) serves as investment adviser to the Portfolio. The Portfolio currently offers two classes of shares. The Service Shares (the “Shares”) are offered by this Prospectus in connection with investment in and payments under variable annuity contracts and variable life insurance contracts (collectively, “variable insurance contracts”), as well as certain qualified retirement plans.

For the purpose of this Prospectus, any reference to the “Janus Henderson funds” is inclusive of all series of the Trust, collectively, unless otherwise noted in this Prospectus.

Portfolio summary

Janus Henderson Overseas Portfolio

Ticker:

N/A

Service Shares

Investment Objective

Janus Henderson Overseas Portfolio (“Overseas Portfolio”) seeks long-term growth of capital.

Fees and Expenses of the Portfolio

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Management Fees(1)		0.77%
Distribution/Service (12b-1) Fees		0.25%
Other Expenses		0.11%
Total Annual Fund Operating Expenses		1.13%

(1)

EXAMPLE:

	1 Year	3 Years	5 Years	10 Years
Service Shares	$ 115	$ 359	$ 622	$ 1,375

Principal investment strategies

The Portfolio pursues its investment objective by investing, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in securities of issuers or companies from countries outside of the United States. The Portfolio normally invests in a portfolio of 30-50 securities of issuers from several different countries, excluding the United States, and it may, under unusual circumstances, invest all or substantially all of its assets in a single country. The Portfolio may invest up to 20% of its net assets, measured at the time of purchase, in U.S. issuers. An issuer is deemed to be from a country or countries outside of the United States if one or more of the following tests are met: (i) the issuer is organized in, or its primary business office or principal trading market of its equity is located in, a country outside of the United States; (ii) a majority of the issuer’s revenues are derived from outside of the United States; or (iii) a majority of the issuer’s assets are located outside of the United States. The Portfolio may have significant exposure to emerging markets. The Portfolio typically invests in equity securities (such as stocks or any other security representing an ownership interest) in all market capitalizations.

2 | Janus Henderson Overseas Portfolio

Portfolio management applies a “bottom-up” approach in choosing investments. In other words, portfolio management looks at companies one at a time to determine if a company is an attractive investment opportunity and if it is consistent with the Portfolio’s investment policies. Portfolio management will generally consider selling a security when, among other things, the security no longer reflects portfolio management’s investment thesis, the security approaches or exceeds its targeted value, there has been a change in a security’s risk/reward potential, or a better idea is identified.

The Portfolio may invest in equity and debt securities of real estate-related companies. These securities may include common stocks and other securities, including, but not limited to, real estate-backed securities, securities of real estate investment trusts (“REITs”) and similar REIT-like entities.

The Portfolio may take long or short positions in derivatives. Derivatives are instruments that have a value derived from, or directly linked to, an underlying asset, such as equity securities, commodities, currencies, interest rates, or market indices. For purposes of meeting its 80% investment policy, the Portfolio may include derivatives that have characteristics similar to the securities in which the Portfolio may directly invest. The types of derivatives in which the Portfolio may invest include options, futures, swaps, warrants, and forward currency contracts. The Portfolio may use derivatives to hedge, to earn income or enhance returns, as a substitute for securities in which the Portfolio invests, to increase or decrease the Portfolio’s exposure to a particular market, to adjust the Portfolio’s currency exposure relative to its benchmark index, to gain access to foreign markets where direct investment may be restricted or unavailable, or to manage the Portfolio’s risk profile.

Principal investment risks

The biggest risk is that the Portfolio’s returns will vary, and you could lose money. The Portfolio is designed for long-term investors seeking an international equity portfolio, including common stocks. The principal risks associated with investing in the Portfolio are set forth below.

3 | Janus Henderson Overseas Portfolio

securities of foreign issuers may also be affected by currency risk, as the value of these securities may also be affected by changes in the issuer’s local currency.

Emerging Markets Risk. Emerging market securities involve a number of risks, which may result from less government supervision and regulation of business and industry practices (including the potential lack of strict finance and accounting controls and standards), stock exchanges, brokers, and listed companies. Information about emerging market companies, including financial information, may be less available or reliable and the Adviser’s ability to conduct due diligence with respect to such companies may be limited. Accordingly, these investments may be potentially more volatile in price and less liquid than investments in developed securities markets, resulting in greater risk to investors. There is a risk in developing countries that a current or future economic or political crisis could lead to price controls, forced mergers of companies, expropriation or confiscatory taxation, imposition or enforcement of foreign ownership limits, seizure, nationalization, sanctions or imposition of restrictions by various governmental entities on investment and trading, or creation of government monopolies, any of which may have a detrimental effect on the Portfolio’s investments. In addition, the taxation systems at the federal, regional, and local levels in developing or emerging market countries may be less transparent, inconsistently enforced, and subject to change. Emerging markets may be subject to a higher degree of corruption and fraud than developed markets, and financial institutions and transaction counterparties may have less financial sophistication, creditworthiness, and/or resources than participants in developed markets.

Geographic Concentration Risk. To the extent the Portfolio invests a substantial amount of its assets in issuers located in a single country or region, the economic, political, social, regulatory, or other developments or conditions within such country or region will generally have a greater effect on the Portfolio than they would on a more geographically diversified portfolio, which may result in greater losses and volatility. Adverse developments in certain regions could also adversely affect securities of other countries whose economies appear to be unrelated and could have a negative impact on the Portfolio’s performance.

•

Europe Risk. The economies and markets of European countries are often closely connected and interdependent. Changes in regulations on trade, decreasing imports or exports, changes in the exchange rate of European currencies, and recessions among European countries may have a significant adverse effect on the economies of other European countries. Europe has, in certain instances, been susceptible to serious financial hardship, high debt levels, and high levels of unemployment. The markets in Eastern Europe remain relatively undeveloped and can be particularly sensitive to political and economic developments.

4 | Janus Henderson Overseas Portfolio

holdings are also subject to wider price fluctuations and tend to be less liquid than stocks of larger or more established companies, which could have a significant adverse effect on the Portfolio’s returns, especially as market conditions change.

5 | Janus Henderson Overseas Portfolio

of 1940, as amended, which could produce adverse economic consequences for the REIT and its investors, including the Portfolio. Dividends received by the Portfolio from a REIT generally will not constitute qualified dividend income.

An investment in the Portfolio is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance information

Annual Total Returns for Service Shares (calendar year-end)

Best Quarter:

4th Quarter 2020

21.10%

Worst Quarter:

1st Quarter 2020

– 24.95%

Average Annual Total Returns (periods ended 12/31/24)
	1 Year	5 Years	10 Years
Overseas Portfolio
Service Shares	5.58%	6.95%	5.29%
MSCI All Country World ex-USA IndexSM (reflects no deduction for fees, expenses, or taxes, except foreign withholding taxes)	5.53%	4.10%	4.80%

The Portfolio’s broad-based benchmark index is the MSCI All Country World ex-USA Index. The index is described below.

•

The MSCI All Country World ex-USA Index is designed to measure equity market performance in global developed and emerging markets outside the United States.

Management

Investment Adviser: Janus Henderson Investors US LLC

Portfolio Management: Julian McManus is Executive Vice President and Lead Portfolio Manager of the Portfolio, which he has managed or co-managed since January 2018. Christopher O’Malley, CFA, is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since January 2024.

Purchase and sale of Portfolio shares

6 | Janus Henderson Overseas Portfolio

Tax information

Payments to Insurers, Broker-Dealers, and other financial intermediaries

7 | Janus Henderson Overseas Portfolio

Additional information about the Portfolio

Fees and expenses

•

The “Management Fee” is the investment advisory fee rate paid by the Portfolio to the Adviser. Overseas Portfolio pays an investment advisory fee rate that adjusts up or down by a variable rate of up to 0.15% (assuming constant assets) on a monthly basis based upon the Portfolio’s performance relative to its benchmark index during a measurement period. This base fee rate, prior to any performance adjustment, is 0.64%. Refer to “Management Expenses” in this Prospectus for additional information with further description in the Statement of Additional Information (“SAI”).

•

“Other Expenses”

•

Additional investment strategies and general portfolio policies

The Portfolio’s Board of Trustees (“Trustees”) may change the Portfolio’s investment objective or non-fundamental principal investment strategies without a shareholder vote. The Portfolio will notify you in writing at least 60 days before making any such change it considers material. In addition, the Portfolio will provide shareholders with at least 60 days’ notice prior to changing the 80% investment policy. If there is a material change to the Portfolio’s investment objective or principal investment strategies, you should consider whether the Portfolio remains an appropriate investment for you. There is no guarantee that the Portfolio will achieve its investment objective.

8 | Janus Aspen Series

not be required to dispose of any securities. The “Glossary of Investment Terms” includes descriptions of investment terms used throughout the Prospectus.

Security Selection

Cash Position

Derivatives

Emerging Markets

ESG Integration

9 | Janus Aspen Series

Illiquid Investments

Initial Public Offerings and Secondary Offerings

Leverage

Portfolio Turnover

REITs and Real Estate-Related Securities

The Portfolio may invest in equity and debt securities of real estate-related companies. These securities may include common stocks, preferred stocks, and other securities, including, but not limited to, mortgage-backed securities, real estate-backed securities, securities of REITs and similar REIT-like entities (such as real estate operating companies (“REOCs”)). A REIT is an entity that invests in real estate-related projects, such as properties, mortgage loans, and construction loans. REITs are often categorized as equity REITs, mortgage REITs, and hybrid REITs. An equity REIT, the most common type of REIT, invests primarily in the fee ownership of land and buildings. An equity REIT derives its income primarily from rental income but may also realize capital gains or losses by selling real estate properties in its portfolio that have appreciated or depreciated in value. A mortgage REIT invests primarily in mortgages on real estate, which may secure construction, development, or long-term loans. A mortgage REIT generally derives its income from interest payments on the credit it has extended. A hybrid REIT combines the characteristics of equity REITs and mortgage REITs, generally by holding both ownership interests and mortgage interests in real estate.

10 | Janus Aspen Series

same favorable tax treatment that is accorded to REITs, REOCs are typically subject to fewer restrictions than REITs, including the ability to retain and/or reinvest funds from operations and more flexibility in terms of the real estate investments they can make.

Securities Lending

Short Sales

Special Situations

11 | Janus Aspen Series

a redirection of free cash flow. For example, issuers undergoing significant capital changes may include companies involved in spin-offs, sales of divisions, mergers or acquisitions, companies involved in bankruptcy proceedings, or companies initiating large changes in their debt to equity ratio. Companies that are redirecting cash flows may be reducing debt, repurchasing shares, or paying dividends. Special situations may also result from: (i) significant changes in industry structure through regulatory developments or shifts in competition; (ii) a new or improved product, service, operation, or technological advance; (iii) changes in senior management or other extraordinary corporate event; (iv) differences in market supply of and demand for the security; or (v) significant changes in cost structure. Investments in “special situations” companies can present greater risks than investments in companies not experiencing special situations, and the Portfolio’s performance could be adversely impacted if the securities selected decline in value or fail to appreciate in value.

Swap Agreements

Other Types of Investments

•

debt securities (such as bonds, notes, sovereign debt, and debentures)

•

preferred stocks and securities convertible into common stocks or preferred stocks

•

indexed/structured securities (such as commercial and residential mortgage- and asset-backed securities)

•

securities purchased on a when-issued, delayed delivery, or forward commitment basis

•

equity and fixed-income securities issued in private placement transactions

Risks of the Portfolio

12 | Janus Aspen Series

or more types of cash management vehicles or in time deposits. In addition, the Portfolio may be exposed to counterparty risk through its investments in certain securities, including, but not limited to, repurchase agreements, debt securities, and derivatives (including various types of swaps, futures, and options). The Portfolio intends to enter into financial transactions with counterparties that the Adviser believes to be creditworthy at the time of the transaction. There is always the risk that the Adviser’s analysis of a counterparty’s creditworthiness is incorrect or may change due to market conditions. To the extent that the Portfolio focuses its transactions with a limited number of counterparties, it will have greater exposure to the risks associated with one or more counterparties.

13 | Janus Aspen Series

consideration of financially material ESG Factors has the potential to provide better risk-adjusted returns, ESG Factors may not be considered for every investment decision and there is no guarantee that the consideration of ESG Factors will result in better performance. In addition, information related to ESG Factors provided by issuers and third parties, which portfolio management may utilize, continues to develop, and may be incomplete, inaccurate, use different methodologies or be applied differently across issuers and industries. Further, the U.S. regulatory landscape regarding the use of ESG Factors in investing is still developing and future rules and regulations may require the Portfolio to modify or alter its investment process and/or how it discloses its consideration of ESG Factors.

•

Transaction Costs Risk. Costs of buying, selling, and holding foreign securities, including brokerage, tax, and custody costs, may be higher than those involved in domestic transactions.

14 | Janus Aspen Series

•

15 | Janus Aspen Series

Investments in foreign securities, particularly those of issuers located in emerging market countries, tend to have greater exposure to liquidity risk than domestic securities. In unusual market conditions, even normally liquid securities may be affected by a degree of liquidity risk (i.e., if the number and capacity of traditional market participants is reduced). An inability to sell one or more portfolio positions can adversely affect the Portfolio’s value or prevent the Portfolio from being able to take advantage of other investment opportunities. Liquidity risk may be increased to the extent that the Portfolio invests in Rule 144A and other securities exempt from certain registration requirements that are deemed to be illiquid investments.

•

16 | Janus Aspen Series

exposure to a large number of properties, such properties may be concentrated in a particular industry, region, or housing type, making such investments more vulnerable to unfavorable developments to economic or market events. Certain “special purpose” REITs in which the Portfolio may invest focus their assets in specific real property sectors, such as hotels, shopping malls, nursing homes, or warehouses, and are therefore subject to the specific risks associated with adverse developments in these sectors. The Portfolio’s shareholders will indirectly bear their proportionate share of the REIT’s expenses, in addition to their proportionate share of the Portfolio’s expenses. The value of investments in REOCs will generally be affected by the same factors that adversely affect REIT investments; however, REOCs may also be adversely affected by income streams derived from businesses other than real estate ownership.

Variable Interest Entities (“VIEs”) Risk. In seeking exposure to Chinese issuers, the Portfolio may invest in VIE structures, which in addition to the risks listed under “Foreign Exposure Risk” and “Emerging Markets Risk,” present additional complexity and risks that may not be present in other organizational structures. VIE structures enable foreign investors, such as the Portfolio, to obtain exposure to a Chinese operating company through a contractual agreement without having equity ownership of such company. The Chinese government could determine at any time, and without notice, that the agreements establishing the VIE structure do not comply with Chinese law and regulations, which could result in potential penalties, revocation of business and operating licenses, or forfeiture of ownership interests. Additionally, because VIEs operate using contractual arrangements rather than having equity ownership, foreign investors do not have rights of direct equity owners including rights to residual profits or control over management.

17 | Janus Aspen Series

Management of the Portfolio

Investment adviser

Management expenses

Overseas Portfolio pays an investment advisory fee rate that may adjust up or down based on the Portfolio’s performance relative to the cumulative investment record of its performance fee benchmark index (referred to in this section as the “benchmark index”), the MSCI All Country World ex-USA Index, over a rolling 36-month performance measurement period.

19 | Janus Aspen Series

Portfolio Name	Base Fee Rate (%)	Full Performance Rate vs. Benchmark Index	Performance Adjusted Investment Advisory Fee Rate/ Actual Compensation Rate Paid to Adviser (%) (for the fiscal year ended December 31, 2024)
Overseas Portfolio	0.64	±7.00%	0.77

The calculation of the performance adjustment applies as follows:

Investment Advisory Fee = Base Fee Rate +/– Performance Adjustment

20 | Janus Aspen Series

Portfolio management

Overseas Portfolio

Co-Portfolio Managers Julian McManus and Christopher O’Malley are responsible for the day-to-day management of the Portfolio. Mr. McManus, as Lead Portfolio Manager, has the authority to exercise final decision-making on the overall portfolio.

Julian McManus is Executive Vice President and Lead Portfolio Manager of Overseas Portfolio, which he has managed or co-managed since January 2018. Mr. McManus is also Portfolio Manager of other Janus Henderson accounts. He holds a Bachelor of Arts degree in Japanese and Law from the University of London, where he graduated with honors.

Christopher O’Malley, CFA, is Executive Vice President and Co-Portfolio Manager of Overseas Portfolio, which he has co-managed since January 2024. Mr. O’Malley is also Portfolio Manager of other Janus Henderson accounts and performs duties as an analyst. He joined the Adviser in 2017. Mr. O’Malley holds a Bachelor of Arts degree, with a concentration in Political Science and Economics, from Providence College and a Master of Business Administration degree, with concentrations in Finance, Accounting, and General Management, from the University of Chicago Booth School of Business. He holds the Chartered Financial Analyst designation.

Conflicts of Interest

21 | Janus Aspen Series

Other information

Classes of Shares

Closed Portfolio Policies

Liquidation/Reorganization of a Portfolio

DISTRIBUTION OF THE Portfolio

22 | Janus Aspen Series

Distributions and taxes

Distributions

Distribution Schedule

How Distributions Affect the Portfolio’s NAV

TAXES

Taxes on Distributions

Taxation of the Portfolio

23 | Janus Aspen Series

Shareholder’s guide

Pricing of portfolio shares

24 | Janus Aspen Series

Distribution, servicing, and administrative fees

Distribution and Shareholder Servicing Plan

Administrative Fees

Payments to financial intermediaries by the Adviser or its affiliates

25 | Janus Aspen Series

Purchases

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Refer to the prospectus of the appropriate insurance company separate account or your plan documents for information on how to invest in the Shares of the Portfolio. Under certain circumstances, the Portfolio may permit an in-kind purchase of Shares. Participating insurance companies and certain other designated organizations are authorized to receive purchase orders on the Portfolio’s behalf. As discussed under “Payments to Financial Intermediaries by the Adviser or its Affiliates,” the Adviser and its affiliates make payments to selected insurance companies, qualified plan service providers, or their affiliates, or other financial intermediaries that were instrumental in the acquisition or retention of accounts for the Portfolio or that provide services in connection with investments in the Portfolio. You should consider such arrangements when evaluating any recommendation of the Portfolio.

26 | Janus Aspen Series

Potential Conflicts

Redemptions

Large Shareholder Redemptions

27 | Janus Aspen Series

Redemptions In-Kind

Excessive trading

Excessive and Short-Term Trading Policies and Procedures

The Janus Henderson funds attempt to deter excessive trading through at least the following methods:

•

fair valuation of securities as described under “Pricing of Portfolio Shares”; and

•

trade monitoring.

The Portfolio’s Trustees may approve from time to time a redemption fee to be imposed by any Janus Henderson fund, subject to 60 days’ notice to shareholders of that fund.

28 | Janus Aspen Series

particular intermediaries may vary depending on the systems’ capabilities, applicable contractual and legal restrictions, and cooperation of those intermediaries.

The Portfolio’s policies and procedures regarding excessive trading may be modified at any time by the Portfolio’s Trustees.

Excessive Trading Risks

Availability of Portfolio Holdings Information

•

29 | Janus Aspen Series

•

Top Holdings. The Portfolio’s top portfolio holdings, in order of position size and as a percentage of the Portfolio’s total portfolio, are available monthly with a 15-day lag.

•

Other Information. The Portfolio may occasionally provide security breakdowns (e.g., industry, sector, regional, market capitalization, and asset allocation) and specific portfolio level performance attribution information and statistics monthly with a 15-day lag. Top/bottom equity securities ranked by performance attribution, including the percentage attribution to Portfolio performance, average Portfolio weighting, and other relevant data points, may be provided monthly with a 15-day lag.

Shareholder communications

30 | Janus Aspen Series

Financial highlights

Overseas Portfolio – Service Shares

	Years ended December 31
	2024	2023	2022	2021	2020
Net Asset Value, Beginning of Period	$40.08	$36.76	$41.02	$36.57	$31.90
Income/(Loss) from Investment Operations:
Net investment income/(loss)(1)	0.52	0.49	0.61	0.46	0.27
Net realized and unrealized gain/(loss)	1.73	3.39	(4.25)	4.41	4.77
Total from Investment Operations	2.25	3.88	(3.64)	4.87	5.04
Less Dividends and Distributions:
Dividends (from net investment income)	(0.56)	(0.56)	(0.62)	(0.42)	(0.37)
Total Dividends and Distributions	(0.56)	(0.56)	(0.62)	(0.42)	(0.37)
Net Asset Value, End of Period	$41.77	$40.08	$36.76	$41.02	$36.57
Total Return*	5.58%	10.58%	(8.84)%	13.32%	15.99%
Net Assets, End of Period (in thousands)	$503,771	$509,077	$502,240	$570,494	$540,349
Ratios to Average Net Assets
Ratio of Gross Expenses	1.13%	1.14%	1.14%	1.12%	1.08%
Ratio of Net Expenses (After Waivers and Expense Offsets)	1.13%	1.14%	1.14%	1.12%	1.08%
Ratio of Net Investment Income/(Loss)	1.21%	1.25%	1.67%	1.14%	0.92%
Portfolio Turnover Rate	39%	30%	36%	21%	21%

*	Total return includes adjustments in accordance with generally accepted accounting principles required at the year or period end and are not annualized for periods of less than one full year. Total return does not include fees, charges, or expenses imposed by the variable annuity and life insurance contracts for which Janus Aspen Series serves as an underlying investment vehicle.
(1)	Per share amounts are calculated based on average shares outstanding during the year or period.

31 | Janus Aspen Series

Glossary of investment terms

Equity and Debt Securities

Convertible securities are preferred stocks or bonds that pay a fixed dividend or interest payment and are convertible into common stock at a specified price or conversion ratio.

32 | Janus Aspen Series

Rule 144A securities are securities that are not registered for sale to the general public under the Securities Act of 1933, as amended, but that may be resold to certain institutional investors.

Futures, Options, and Other Derivatives

Equity swaps involve the exchange by two parties of future cash flow (e.g., one cash flow based on a referenced interest rate and the other based on the performance of stock or a stock index).

33 | Janus Aspen Series

instrument appreciates). Indexed/structured securities may have return characteristics similar to direct investments in the underlying instruments and may be more volatile than the underlying instruments.

Interest rate swaps involve the exchange by two parties of their respective commitments to pay or receive interest (e.g., an exchange of floating rate payments for fixed rate payments).

Other Investments, Strategies, and/or Techniques

Repatriation is the ability to move liquid financial assets from a foreign country to an investor’s country of origin.

34 | Janus Aspen Series

janushenderson.com/VIT

151 Detroit Street
Denver, CO 80206-4805
1-877-335-2687

The Trust’s Investment Company Act File No. is 811-7736.

This Prospectus describes Janus Henderson Research Portfolio (the “Portfolio”), a series of Janus Aspen Series (the “Trust”). Janus Henderson Investors US LLC (the “Adviser”) serves as investment adviser to the Portfolio. The Portfolio currently offers two classes of shares. The Service Shares (the “Shares”) are offered by this Prospectus in connection with investment in and payments under variable annuity contracts and variable life insurance contracts (collectively, “variable insurance contracts”), as well as certain qualified retirement plans.

For the purpose of this Prospectus, any reference to the “Janus Henderson funds” is inclusive of all series of the Trust, collectively, unless otherwise noted in this Prospectus.

Portfolio summary

Janus Henderson Research Portfolio

Ticker:

N/A

Service Shares

Investment Objective

Janus Henderson Research Portfolio (“Research Portfolio”) seeks long-term growth of capital.

Fees and Expenses of the Portfolio

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Management Fees(1)		0.56%
Distribution/Service (12b-1) Fees		0.25%
Other Expenses		0.11%
Total Annual Fund Operating Expenses		0.92%

(1)

EXAMPLE:

	1 Year	3 Years	5 Years	10 Years
Service Shares	$ 94	$ 293	$ 509	$ 1,131

Principal investment strategies

The Portfolio pursues its investment objective by investing primarily in common stocks selected for their growth potential. The Portfolio may invest in companies of any size, from larger, well-established companies to smaller, emerging growth companies. The Portfolio is classified as nondiversified, which allows it to hold larger positions in more securities compared to a portfolio that is classified as diversified.

The Adviser’s equity research analysts (the “Central Research Team”) select investments for the Portfolio that represent the Central Research Team’s high-conviction investment ideas in all market capitalizations and styles. The Central Research Team conducts fundamental analysis with a focus on “bottom-up” research, quantitative modeling, and valuation analysis. Using this research process, analysts rate their stocks based upon attractiveness. Stocks considered to be attractive may have all or some of the following characteristics: (i) good and preferably growing free cash flow, (ii) strong and defensible market position, (iii) healthy risk/return profile, (iv) exemplary governance, and (v) attractive valuation. Analysts bring their high-conviction ideas to their respective sector teams. Each sector team compares the appreciation and risk potential of its high-conviction ideas and constructs a sector sleeve that is intended to maximize the best risk-reward opportunities. The sector

2 | Janus Henderson Research Portfolio

sleeves are then combined to form the Portfolio’s overall portfolio. The Portfolio Oversight Team, which includes portfolio management, oversees the overall portfolio to manage unintended style risks. Although the Central Research Team may find high-conviction investment ideas anywhere in the world, the Central Research Team emphasizes investments in securities of U.S.-based issuers for the Portfolio.

Principal investment risks

Growth Securities Risk. Securities of companies perceived to be “growth” companies may be more volatile than other stocks and may involve special risks. If portfolio management’s perception of a company’s growth potential is not realized, the securities purchased may not perform as expected, reducing the Portfolio’s returns. In addition, because different types of stocks tend to shift in and out of favor depending on market and economic conditions, “growth” stocks may perform differently from other types of securities and the market as a whole. The Portfolio’s Central Research Team compares and broadly matches the Portfolio’s sector weights to those of a growth-based index. If growth stocks are out of favor, sectors that are larger in a growth index may underperform, leading to Portfolio underperformance relative to indices less biased toward growth stocks.

3 | Janus Henderson Research Portfolio

perform, the value of the Portfolio’s holdings could also decrease if there are deteriorating economic or market conditions or perceptions regarding the industries in which the issuers of securities the Portfolio holds participate.

•

An investment in the Portfolio is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance information

4 | Janus Henderson Research Portfolio

one or more additional indices that have investment characteristics similar to those of the Portfolio. All figures assume reinvestment of dividends and distributions.

Annual Total Returns for Service Shares (calendar year-end)

Best Quarter:

2nd Quarter 2020

26.63%

Worst Quarter:

2nd Quarter 2022

– 22.32%

Average Annual Total Returns (periods ended 12/31/24)
	1 Year	5 Years	10 Years
Research Portfolio
Service Shares	34.96%	16.49%	14.25%
Russell 1000® Index (reflects no deduction for fees, expenses, or taxes)	24.51%	14.28%	12.87%
Russell 1000® Growth Index (reflects no deduction for fees, expenses, or taxes)	33.36%	18.96%	16.78%
S&P 500® Index (reflects no deduction for fees, expenses, or taxes)	25.02%	14.53%	13.10%

•

The Russell 1000 Index measures the performance of the large-cap segment of the U.S. equity universe.

•

The Russell 1000 Growth Index measures the performance of those Russell 1000 companies with higher price-to-book ratios and higher forecasted growth values.

•

The S&P 500 Index is a commonly recognized, market capitalization-weighted index of 500 widely held equity securities, designed to measure broad U.S. equity performance.

Management

Investment Adviser: Janus Henderson Investors US LLC

5 | Janus Henderson Research Portfolio

Purchase and sale of Portfolio shares

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Redemptions, like purchases, may be effected only through the separate accounts of participating insurance companies or through qualified retirement plans. Requests are duly processed at the net asset value next calculated after an order is received in good order by the Portfolio or its agents. Refer to the appropriate separate account prospectus or plan documents for details.

Tax information

Payments to Insurers, Broker-Dealers, and other financial intermediaries

6 | Janus Henderson Research Portfolio

Additional information about the Portfolio

Fees and expenses

•

The “Management Fee” is the investment advisory fee rate paid by the Portfolio to the Adviser. Research Portfolio pays an investment advisory fee rate that adjusts up or down by a variable rate of up to 0.15% (assuming constant assets) on a monthly basis based upon the Portfolio’s performance relative to its benchmark index during a measurement period. This base fee rate, prior to any performance adjustment, is 0.64%. Refer to “Management Expenses” in this Prospectus for additional information with further description in the Statement of Additional Information (“SAI”).

•

“Other Expenses”

•

Additional investment strategies and general portfolio policies

7 | Janus Aspen Series

Security Selection

The Portfolio pursues its investment objective by investing primarily in common stocks selected for their growth potential. The Central Research Team selects investments that represent their high-conviction investment ideas in all market capitalizations and styles. The Central Research Team conducts fundamental analysis with a focus on “bottom-up” research, quantitative modeling, and valuation analysis. Using this research process, analysts rate their stocks based upon attractiveness. Stocks considered to be attractive may have all or some of the following characteristics: (i) good and preferably growing free cash flow, (ii) strong and defensible market position, (iii) healthy risk/return profile, (iv) exemplary governance, and (v) attractive valuation. Analysts bring their high-conviction ideas to their respective sector teams. Each sector team compares the appreciation and risk potential of its high-conviction ideas and constructs a sector sleeve that is intended to maximize the best risk-reward opportunities. The sector sleeves are then combined to form the Portfolio’s overall portfolio. The Portfolio Oversight Team, which includes portfolio management, oversees the overall portfolio to manage unintended style risks. Although the Central Research Team may find high-conviction investment ideas anywhere in the world with respect to the Portfolio, the Central Research Team emphasizes investments in securities of U.S.-based issuers for the Portfolio. Positions may be sold when, among other things, there is no longer high conviction in the return potential of the investment, if the risk characteristics have caused a re-evaluation of the opportunity, or if the investment thesis for owning a position has changed. This may occur if the stock has appreciated and reflects the anticipated value, if another company represents a better risk-reward opportunity, or if the investment’s fundamental characteristics deteriorate. Securities may also be sold from the portfolio to rebalance sector weightings.

Cash Position

Emerging Markets

ESG Integration

8 | Janus Aspen Series

Foreign Securities

Illiquid Investments

Initial Public Offerings and Secondary Offerings

Leverage

Nondiversification

Portfolio Turnover

9 | Janus Aspen Series

REITs and Real Estate-Related Securities

Securities Lending

Short Sales

10 | Janus Aspen Series

a short squeeze occurs, it is more likely that the Portfolio will have to cover its short sale at an unfavorable price and potentially reduce or eliminate any gain, or cause a loss, as a result of the short sale. Because there is no upper limit to the price a borrowed security may reach prior to closing a short position, the Portfolio’s losses are potentially unlimited in a short sale transaction. The Portfolio’s gains and losses will also be decreased or increased, as the case may be, by the amount of any dividends, interest, or expenses, including transaction costs and borrowing fees, the Portfolio may be required to pay in connection with a short sale. Such payments may result in the Portfolio having higher expenses than a portfolio that does not engage in short sales and may negatively affect the Portfolio’s performance.

Special Situations

Other Types of Investments

•

debt securities (such as bonds, notes, and debentures)

•

preferred stocks and securities convertible into common stocks or preferred stocks

•

indexed/structured securities (such as commercial and residential mortgage- and asset-backed securities)

•

securities purchased on a when-issued, delayed delivery, or forward commitment basis

•

equity and fixed-income securities issued in private placement transactions

Risks of the Portfolio

11 | Janus Aspen Series

12 | Janus Aspen Series

to be economically tied to a country or countries if one or more of the following tests are met: (i) the issuer is organized in, or its primary business office or principal trading market of its equity is located in, the country; (ii) a majority of the issuer’s revenues are derived from one or more countries; or (iii) a majority of the issuer’s assets are located in one or more countries. Investments in foreign securities, including securities of foreign and emerging market governments, may involve greater risks than investing in domestic securities because the Portfolio’s performance may depend on factors other than the performance of a particular company. These factors include:

•

Transaction Costs Risk. Costs of buying, selling, and holding foreign securities, including brokerage, tax, and custody costs, may be higher than those involved in domestic transactions.

13 | Janus Aspen Series

developments. The Portfolio’s investments, if any, in multiple companies in a particular industry or economic sector may increase the Portfolio’s exposure to industry and sector risk.

•

14 | Janus Aspen Series

•

15 | Janus Aspen Series

16 | Janus Aspen Series

Management of the Portfolio

Investment adviser

Management expenses

Research Portfolio pays an investment advisory fee rate that may adjust up or down based on the Portfolio’s performance relative to the cumulative investment record of its performance fee benchmark index (referred to in this section as the “benchmark index”), the Russell 1000 Growth Index, over a rolling 36-month performance measurement period.

17 | Janus Aspen Series

Portfolio Name	Base Fee Rate (%)	Full Performance Rate vs. Benchmark Index	Performance Adjusted Investment Advisory Fee Rate/ Actual Compensation Rate Paid to Adviser (%) (for the fiscal year ended December 31, 2024)
Research Portfolio	0.64	± 5.00%	0.56

The calculation of the performance adjustment applies as follows:

Investment Advisory Fee = Base Fee Rate +/– Performance Adjustment

18 | Janus Aspen Series

Portfolio management

Research Portfolio

The Central Research Team selects investments for Research Portfolio and has done so since May 2017. The Central Research Team consists of the Adviser’s equity research analysts. The Portfolio Oversight Team oversees the Portfolio’s holdings. Joshua Cummings and John Jordan are members of the Portfolio Oversight Team and are primarily responsible for the day-to-day management of the Portfolio.

Joshua Cummings, CFA, is Head of the Consumer Sector Team and the Communications Sector Team at Janus Henderson Investors. He is Executive Vice President and Co-Portfolio Manager of Research Portfolio, which he has co-managed since January 2024. Mr. Cummings is also Portfolio Manager of other Janus Henderson accounts and performs duties as an analyst. He joined the Adviser in 2016. He holds a Bachelor of Arts degree in Economics from Colby College and a Master of Business Administration degree in Finance and Accounting from New York University. Mr. Cummings holds the Chartered Financial Analyst designation.

John Jordan is Head of the Financials Sector Team at Janus Henderson Investors. He is Executive Vice President and Co-Portfolio Manager of Research Portfolio, which he has co-managed since January 2024. Mr. Jordan is also Portfolio Manager of other Janus Henderson accounts and performs duties as an analyst. He joined the Adviser in 2008. He holds a Bachelor of Arts degree in History and Economics from the University of Virginia where he graduated with high distinction and was a member of Phi Beta Kappa. Mr. Jordan also holds a Juris Doctor from Yale Law School.

Conflicts of Interest

19 | Janus Aspen Series

Other information

Classes of Shares

Closed Portfolio Policies

Liquidation/Reorganization of a Portfolio

DISTRIBUTION OF THE Portfolio

20 | Janus Aspen Series

Distributions and taxes

Distributions

Distribution Schedule

How Distributions Affect the Portfolio’s NAV

TAXES

Taxes on Distributions

Taxation of the Portfolio

21 | Janus Aspen Series

Shareholder’s guide

Pricing of portfolio shares

22 | Janus Aspen Series

Distribution, servicing, and administrative fees

Distribution and Shareholder Servicing Plan

Administrative Fees

Payments to financial intermediaries by the Adviser or its affiliates

23 | Janus Aspen Series

Purchases

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Refer to the prospectus of the appropriate insurance company separate account or your plan documents for information on how to invest in the Shares of the Portfolio. Under certain circumstances, the Portfolio may permit an in-kind purchase of Shares. Participating insurance companies and certain other designated organizations are authorized to receive purchase orders on the Portfolio’s behalf. As discussed under “Payments to Financial Intermediaries by the Adviser or its Affiliates,” the Adviser and its affiliates make payments to selected insurance companies, qualified plan service providers, or their affiliates, or other financial intermediaries that were instrumental in the acquisition or retention of accounts for the Portfolio or that provide services in connection with investments in the Portfolio. You should consider such arrangements when evaluating any recommendation of the Portfolio.

24 | Janus Aspen Series

Potential Conflicts

Redemptions

Large Shareholder Redemptions

Redemptions In-Kind

25 | Janus Aspen Series

Excessive trading

Excessive and Short-Term Trading Policies and Procedures

The Janus Henderson funds attempt to deter excessive trading through at least the following methods:

•

fair valuation of securities as described under “Pricing of Portfolio Shares”; and

•

trade monitoring.

The Portfolio’s Trustees may approve from time to time a redemption fee to be imposed by any Janus Henderson fund, subject to 60 days’ notice to shareholders of that fund.

The Portfolio’s policies and procedures regarding excessive trading may be modified at any time by the Portfolio’s Trustees.

26 | Janus Aspen Series

Excessive Trading Risks

Availability of Portfolio Holdings Information

•

Top Holdings. The Portfolio’s top portfolio holdings, in order of position size and as a percentage of the Portfolio’s total portfolio, are available monthly with a 15-day lag.

•

Other Information. The Portfolio may occasionally provide security breakdowns (e.g., industry, sector, regional, market capitalization, and asset allocation) and specific portfolio level performance attribution information and statistics monthly with a 15-day lag. Top/bottom equity securities ranked by performance attribution, including the percentage attribution to Portfolio performance, average Portfolio weighting, and other relevant data points, may be provided monthly with a 15-day lag.

27 | Janus Aspen Series

Financial highlights

Research Portfolio – Service Shares

	Years ended December 31
	2024	2023	2022	2021	2020
Net Asset Value, Beginning of Period	$43.06	$30.17	$54.34	$47.78	$39.64
Income/(Loss) from Investment Operations:
Net investment income/(loss)(1)	(0.16)	(0.03)	—(2)	(0.13)	0.03
Net realized and unrealized gain/(loss)	15.09	12.94	(16.34)	9.41	11.80
Total from Investment Operations	14.93	12.91	(16.34)	9.28	11.83
Less Dividends and Distributions:
Dividends (from net investment income)	—	(0.02)	—	(0.01)	(0.09)
Distributions (from capital gains)	(1.55)	—	(7.83)	(2.71)	(3.60)
Total Dividends and Distributions	(1.55)	(0.02)	(7.83)	(2.72)	(3.69)
Net Asset Value, End of Period	$56.44	$43.06	$30.17	$54.34	$47.78
Total Return*	34.96%	42.81%	(30.06)%	20.05%	32.58%
Net Assets, End of Period (in thousands)	$194,263	$156,104	$117,437	$184,641	$172,198
Ratios to Average Net Assets
Ratio of Gross Expenses	0.92%	0.82%	0.81%	0.85%	0.85%
Ratio of Net Expenses (After Waivers and Expense Offsets)	0.92%	0.82%	0.81%	0.85%	0.85%
Ratio of Net Investment Income/(Loss)	(0.30)%	(0.09)%	(0.01)%	(0.26)%	0.08%
Portfolio Turnover Rate	27%	27%	30%	33%	33%

*	Total return includes adjustments in accordance with generally accepted accounting principles required at the year or period end and are not annualized for periods of less than one full year. Total return does not include fees, charges, or expenses imposed by the variable annuity and life insurance contracts for which Janus Aspen Series serves as an underlying investment vehicle.
(1)	Per share amounts are calculated based on average shares outstanding during the year or period.
(2)	Less than $0.005 on a per share basis.

29 | Janus Aspen Series

Glossary of investment terms

Equity and Debt Securities

Convertible securities are preferred stocks or bonds that pay a fixed dividend or interest payment and are convertible into common stock at a specified price or conversion ratio.

30 | Janus Aspen Series

Rule 144A securities are securities that are not registered for sale to the general public under the Securities Act of 1933, as amended, but that may be resold to certain institutional investors.

Futures, Options, and Other Derivatives

Other Investments, Strategies, and/or Techniques

31 | Janus Aspen Series

Repatriation is the ability to move liquid financial assets from a foreign country to an investor’s country of origin.

32 | Janus Aspen Series

janushenderson.com/VIT

151 Detroit Street
Denver, CO 80206-4805
1-877-335-2687

The Trust’s Investment Company Act File No. is 811-7736.

	Service Shares Ticker
Janus Henderson Enterprise Portfolio	N/A