485BPOS

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A
REGISTRATION STATEMENT
(NO. 33-32216)

UNDER THE SECURITIES ACT OF 1933

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Pre-Effective Amendment No.

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Post-Effective Amendment No. 105

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and

REGISTRATION STATEMENT
(NO. 811-05962)

UNDER THE INVESTMENT COMPANY ACT OF 1940

Amendment No. 108

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Vanguard Variable Insurance Funds

(Exact Name of Registrant as Specified in Declaration of Trust)

P.O. Box 2600, Valley Forge, PA 19482
(Address of Principal Executive Office)
Registrant’s Telephone Number (610) 669-1000

Natalie Lamarque, Esquire
P.O. Box 876
Valley Forge, PA 19482

It is proposed that this filing will become effective (check appropriate box)

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immediately upon filing pursuant to paragraph (b)

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on April 28, 2026, pursuant to paragraph (b)

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60 days after filing pursuant to paragraph (a)(1)

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on (date) pursuant to paragraph (a)(1)

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75 days after filing pursuant to paragraph (a)(2)

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on (date) pursuant to paragraph (a)(2) of rule 485 If appropriate, check the following box:

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This post-effective amendment designates a new effective date for a previously filed post-effective amendment.

April 28, 2026

Prospectus

Vanguard Variable Insurance Funds

Balanced Portfolio

This Prospectus contains financial data for the Fund through the fiscal year ended December 31, 2025.

The Securities and Exchange Commission (SEC) has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

Contents

Fund Summary	1
More on the Fund	7
Investment Objective and More on Principal Investment Strategies	7
More on Fund Risks	12
Other Investment Policies	20
Portfolio Holdings	21
Management and Distribution of the Fund	21
Investing in Vanguard Funds	24
Purchase and Redemption of Fund Shares	24
Pricing of Fund Shares	26
Distributions and Taxes	28
Frequent Trading Limitations	29
Financial Highlights	31
Additional Information	33

Fund Summary

Investment Objective

Vanguard Variable Insurance Funds Balanced Portfolio (the “Fund”) seeks to provide long-term capital appreciation and reasonable current income.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy, hold, and sell shares of the Fund. The expenses shown in the table and in the example that follows do not reflect additional fees and expenses associated with the annuity or life insurance program through which you invest. If those additional fees and expenses were included, overall expenses would be higher.

Annual Fund Operating Expenses
(Expenses that you pay each year as a percentage of the value of your investment)


Management Fees	0.19 %
12b-1 Distribution Fee	None
Other Expenses	0.01 %
Total Annual Fund Operating Expenses	0.20 %

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same.

1 Year	3 Years	5 Years	10 Years
$20	$64	$113	$255

Portfolio Turnover

The Fund 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 Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 68% of the average value of its portfolio.

Principal Investment Strategies

The Fund employs an active management approach, investing 60-70% of its assets in dividend-paying and, to a lesser extent, non-dividend-paying common stocks of established large companies. In choosing these stocks, the advisor seeks durable businesses that appear to be undervalued but have prospects for improvement. These stocks are commonly referred to as value stocks. The remaining 30% to 40% of the Fund’s assets are invested mainly in fixed income securities that the advisor believes will generate a moderate level of current income. These securities include investment-grade corporate bonds, with some exposure to U.S. Treasury bonds, government agency bonds, and mortgage-backed securities.

Principal Risks

As with any investment, an investment in the Fund could lose money over any time period. The Fund’s share price and total return may fluctuate, potentially within a wide range. The principal risks of investing in the Fund are summarized below. Each of the following risks could affect the Fund’s performance:

• General Market Risk. The markets in which the Fund invests can be affected by a variety of factors. These factors, which can be real or perceived, may include economic, market, political, and regulatory conditions and developments as well as local, regional, or global events such as wars, military conflicts, natural disasters, and public health issues. In addition, investor sentiment and expectations regarding these factors can also impact the markets. Different parts of the market, including different industries and sectors as well as different types of securities, may react differently to factors that affect the market. These factors can contribute to market uncertainty, market volatility, and fluctuations in the value of the Fund’s investments, thereby resulting in potential losses to the Fund over short or long periods.

• Investing in Equity Markets. The Fund invests in the equity markets. Equity markets have historically been cyclical, having periods of time when stock values rise and fall. Market volatility can lead to significant fluctuations in stock values, resulting in potential losses to the Fund.

• Market Capitalization (Market Cap). Companies are generally classified into three types of market cap depending on their size: small-, mid-, and large-cap. Companies can be further classified into micro- or mega-cap. Different factors can affect each market cap uniquely, and historically small- and mid-cap stocks have typically been more volatile due to the effects of changing economic conditions. Large companies may not reach the same levels of growth or performance as smaller companies, and they may be slower to react to competitive challenges. The performance of funds that invest in a subset of market caps could diverge from the performance of a fund that is focused on a broader representation of the stock market.

• Value Investing. The Fund’s approach to value investing could cause it to underperform other stock funds that use a different investment style. The

Fund’s investments in value stocks are subject to the risk that the stocks’ valuations do not improve at the anticipated rate or that their returns do not move in tandem with the returns of other investment styles or the broader stock market.

• Information Technology Sector. From time to time, stocks of companies within the information technology sector may make up a significant portion of the Fund’s investment portfolio. As a result, the Fund’s performance may be impacted by the general condition of the information technology sector.

• Investing in Bond Markets. The Fund may be impacted by the general condition of the bond markets and by factors that affect bonds and bond issuers. For example, as a general rule, bond prices and interest rates move in opposite directions. When interest rates rise, bond prices tend to fall, and when interest rates fall, bond prices tend to go up. Bond income also is affected by changes in interest rates. Interest rates can rise or fall for a number of reasons, including, but not limited to, central bank monetary policy, inflationary or deflationary pressures, and changes in general market and economic conditions. Changing interest rates, including, but not limited to, rates that fall below zero, could have unpredictable effects on the overall market and may expose the bond markets in particular to heightened volatility and potential illiquidity. The degree to which the Fund is impacted by certain bond market risks may vary based on factors disclosed in its principal investment strategies, such as the types of bonds in which it invests and the overall credit quality, average maturity, and/or average duration of its bond holdings.

• Interest Rate Risk. During periods of rising interest rates, bond prices overall may decline, which could result in a decline in the Fund’s value. The prices of longer-term bonds are more sensitive to changes in interest rates than the prices of shorter-term bonds.

• Income Risk. During periods of falling interest rates, the Fund’s income may decline. The income paid by shorter-term bonds is subject to a higher degree of fluctuation than the income paid by longer-term bonds.

• Credit Risk. Credit risk refers to the chance that an issuer will default (fail to meet its credit obligations) or fail to make payments in a timely manner, which could result in a loss to the Fund. In addition, negative perceptions of an issuer’s ability to make payments can cause the price of a security to decline. While all debt securities are subject to credit risk to some extent, those with higher credit quality ratings generally pose less credit risk than those with lower credit quality ratings.

• Call Risk. Certain bonds held by the Fund may be callable. The issuer of a callable bond has the right to “call” (redeem) the bond before its maturity date. Calls on bonds held by the Fund would result in the Fund losing any price appreciation above the bond’s call price. In addition, because bond calls occur more frequently during periods of falling interest rates, the Fund likely would be forced to reinvest the proceeds of any called bonds at a lower interest rate than that of the called bonds, resulting in a decline in the Fund’s income and a potential loss in the value of the Fund’s investments. Frequent bond calls and subsequent reinvestments of the proceeds also would increase the Fund’s turnover rate.

• Prepayment Risk. Certain bonds are subject to risks associated with prepayment. Prepayment risk for callable bonds is described under Call Risk. With respect to mortgage-backed, asset-backed, and similar debt securities, prepayment typically refers to borrowers repaying their debt early (e.g., before the maturity date). Prepayment of bonds held by the Fund would result in the Fund losing any price appreciation above the amount repaid (or the bond’s call price, in the case of callable bonds). In addition, because prepayments occur more frequently in low interest rate environments, the Fund likely would be forced to reinvest the proceeds from any prepayments at a lower interest rate than when the prepaid bonds were purchased, resulting in a decline in the Fund’s income and a potential loss in the value of the Fund’s investments. Frequent prepayments and subsequent reinvestment of the proceeds also would increase the Fund’s turnover rate.

• Extension Risk. During periods of rising interest rates, certain bonds held by the Fund may be paid off substantially more slowly than originally anticipated. As a result, the value of the bonds may fall, resulting in a decline in the Fund’s income and a potential loss in the value of the Fund’s investments.

• Active Management. The Fund is actively managed. The advisor’s security selection and/or strategy execution could cause the Fund to underperform relevant securities markets or other funds with a similar investment objective.

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

Annual Total Returns

fees and expenses that are deducted by the annuity or life insurance program through which you invest. If such fees and expenses were included in the calculation of the Fund’s returns, the returns would be lower. Keep in mind that the Fund’s past performance does not indicate how the Fund will perform in the future. Updated performance information is available on our website for Financial Advisors at advisors.vanguard.com.

Annual Total Returns — Balanced Portfolio

During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were:

	Total Return	Quarter
Highest	12.21 %	June 30, 2020
Lowest	-13.84 %	March 31, 2020

Average Annual Total Returns for Periods Ended December 31, 2025

	1 Year	5 Years	10 Years
Balanced Portfolio	16.46 %	9.29 %	10.03 %
Composite Stock/Bond Index (reflects no deduction for fees, expenses, or taxes)	14.31 %	9.20 %	10.61 %
Dow Jones U.S. Total Stock Market Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	17.05	13.07	14.21
Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses, or taxes)	7.30	-0.36	2.01

Investment Advisor

Wellington Management Company LLP (Wellington Management)

Portfolio Managers

Loren L. Moran, CFA, Senior Managing Director and Fixed Income Portfolio Manager of Wellington Management. She has managed the fixed income portion of the Fund since 2021 (co-managed since 2017).

Daniel J. Pozen, Senior Managing Director and Equity Portfolio Manager of Wellington Management. He has managed the stock portion of the Fund since 2019.

Purchase and Sale of Fund Shares

The Fund offers its shares only to separate accounts of insurance companies to fund annuity or life insurance contracts. You cannot purchase shares of the Fund directly, but only through an annuity or life insurance contract offered by an insurance company. For information regarding how you, as a contract owner, may allocate and withdraw amounts to, and from, the insurance company separate accounts, please refer to the prospectus for the annuity or life insurance program provided by the insurance company.

Tax Information

The Fund normally distributes its net investment income and net realized capital gains, if any, to its shareholders, which are the insurance company separate accounts that sponsor your variable annuity or variable life insurance contract. The tax consequences to you of your investment in the Fund depend on the provisions of the annuity or life insurance contract through which you invest. For more information on taxes, please refer to the prospectus of the annuity or life insurance contract through which Fund shares are offered. You should consult your own tax advisor with respect to any particular U.S. or non-U.S. tax consequences of your investment in the Fund.

Payments to Financial Intermediaries

The Fund and its advisor do not pay financial intermediaries for sales of Fund shares.

More on the Fund

This Prospectus provides information about Vanguard Variable Insurance Funds Balanced Portfolio, a series of Vanguard Variable Insurance Funds (the “Trust”). Reading this Prospectus will help you decide whether the Fund is the right investment for you. The Fund is a mutual fund used solely as an investment option for annuity or life insurance contracts offered by insurance companies. This means that you cannot purchase shares of the Fund directly, but only through an annuity or life insurance contract offered by an insurance company. The Fund is separate from other Vanguard mutual funds, even when the Fund and a Vanguard mutual fund have the same investment objective and advisor. The Fund’s investment performance will differ from the performance of other Vanguard funds because of differences in the securities held and because of administrative and insurance costs associated with the annuity or life insurance program through which you invest.

As you consider an investment in the Fund, you should take into account your tolerance for fluctuations in the securities markets. The costs of investing are another important consideration. As an owner of the annuity or life insurance contract through which you invest in the Fund, you will pay a proportionate share of the costs of operating the Fund and any transaction costs incurred when the Fund buys or sells securities. These costs can erode a substantial portion of the gross income or the capital appreciation the Fund achieves. Even seemingly small differences can, over time, have a dramatic effect on the Fund’s performance.

Investment Objective and More on Principal Investment Strategies

In this section, you will find more information about the Fund’s investment objective and the principal investment strategies and policies that the Fund uses in pursuit of its investment objective. The Trust’s board of trustees (the “Board”) oversees the Fund’s management. The Board may approve changes to the Fund’s strategies or policies in the interest of shareholders without shareholder approval unless the strategy or policy is designated as fundamental.

Investment Objective

The Fund seeks to provide long-term capital appreciation and reasonable current income.

The Fund’s investment objective is fundamental and may not be materially changed without shareholder approval.

Implementation of Investment Objective

The Fund’s advisor seeks to achieve the Fund’s investment objective by investing the Fund’s assets in equity and fixed income securities.

What is Active Management?

Actively managed funds typically seek to exceed the average returns of a

particular financial market or market segment. The Fund’s advisor will

select securities to buy and sell based on the advisor’s judgments about

companies and their financial prospects, the prices of the securities, and

the markets and the economy in general. In selecting securities, an

advisor may rely on, among other things, research, market forecasts,

quantitative models, and their own judgment and experience.

The Fund is a balanced fund. Balanced funds generally seek to provide some combination of current income and capital appreciation by investing in a mix of stocks and bonds. Because prices of stocks and bonds can respond differently to economic events and influences, a balanced fund should experience less volatility than a fund investing exclusively in stocks.

Wellington Management, the Fund’s advisor, typically invests approximately 60% to 70% of the Fund’s assets in dividend-paying and, to a lesser extent, non-dividend-paying common stocks of established large companies. The remaining 30% to 40% of the Fund’s assets are invested mainly in fixed income securities that the advisor believes will generate a moderate level of current income. Although the mix of stocks and bonds varies from time to time, depending on the advisor’s view of economic and market conditions, the stock portion can be expected to represent at least 60% of the Fund’s holdings under normal circumstances.

Security Selection

The Fund is managed according to traditional methods of active investment management. Securities are bought and sold based on the advisor’s judgments about companies and their financial prospects and about bond issuers and the general level of interest rates. The Fund’s advisor may, at times, select securities that cause the Fund to focus in a particular market sector, which would subject the Fund to proportionately higher exposure to the risks of that sector.

Stock Selection. In selecting stocks, Wellington Management identifies what it considers to be undervalued stocks of primarily established large companies with durable businesses. The advisor considers a stock to be undervalued if company earnings, or potential earnings, are not fully reflected in the stock’s share price. In other words, the current market prices of these large-cap stocks

may be less than what the advisor thinks they should be. The advisor considers a business to be durable if cash flows are resilient across a business cycle, and the business is able to achieve a superior level and duration of growth and/or income. The advisor’s goal is to identify and purchase these securities before their value is recognized by other investors. This is commonly referred to as value investing. The advisor emphasizes stocks that, on average, provide a higher level of dividend income than is generally provided by stocks in the overall market. The advisor also emphasizes the long-term rate of value creation rather than short-term rate of change in sales or earnings. By adhering to this stock selection strategy and by investing in a wide variety of companies and industries, the advisor expects to moderate overall risk. The advisor will generally sell stocks when the valuation is no longer attractive or the business’ stability has been materially impacted.

Stocks of publicly traded companies are often classified according to market capitalization, which is the market value of a company’s outstanding shares. These classifications typically include small-cap, mid-cap, and large-cap. It is important to understand that there is no “official” definition of each type of small-cap, mid-cap, or large-cap and that market capitalization ranges can change over time.

Vanguard Fund	Asset-Weighted Median Market Capitalization
Balanced Portfolio	$330 billion

Bond Selection. In selecting bonds, Wellington Management identifies investment-grade bonds that it believes will generate a moderate level of current income. These may include short-, intermediate-, and long-term corporate, U.S. Treasury, government agency, local currency, and asset-backed bonds, as well as mortgage-backed securities. The advisor does not generally make large adjustments in the average maturity of the Fund’s bond holdings in anticipation of changes in interest rates. The average duration of the Fund’s bond portfolio as of December 31, 2025, was 6.6 years.

The Fund typically invests in bonds that are of investment-grade quality. This means that the bonds are rated at least Baa3 by Moody’s or BBB by S&P Global Ratings, or if unrated, are determined to be of comparable quality by the advisor.

Additional Information Regarding the Fund’s Investments

The Fund’s investments are described in more detail below.

• Large-Cap Stocks represent the largest publicly traded companies, which are often well-established and widely recognized. These companies typically have significant market share, global reach, and a history of financial stability. While they may not offer as much growth potential as smaller companies, they are generally considered more resilient during economic downturns but still not immune from a decrease in price.

• Value Stocks typically represent companies that appear to be undervalued based on financial metrics like price-to-earnings or book value. These stocks are often priced lower relative to their fundamentals, which may reflect temporary challenges, such as recent earnings or negative market sentiment, rather than long-term issues. Value stocks typically offer higher dividend yields than other types of stocks, which can make them attractive to investors seeking income as well as potential price appreciation.

What are Bonds?

Generally speaking, a bond represents a debt or loan issued by, for

example, a corporation, a government, or a financial institution. In most

instances, the issuer agrees to pay the bondholder a fixed, variable, or

floating rate of interest for a specified length of time, and to repay the bond

in full on a specified maturity date. The income earned by a bond (or its

yield, when expressed as a percentage of the bond’s price) can vary

based on its maturity. Longer-term bonds tend to have higher yields than

shorter-term bonds, but are more sensitive to fluctuations in value. By

contrast, shorter-term bonds are less likely to fluctuate in value, but tend

to have lower yields. A bond’s duration is a measure of how sensitive its

price is to changes in interest rates. For example, if a bond has a duration

of 2 years, its price would fall by approximately 2% when interest rates

rise by 1%. On the other hand, the bond’s price would rise by

approximately 2% when interest rates fall by 1%. A bond’s credit quality

rating is an assessment of the issuer’s ability to make timely interest

payments and repay the bond in full on its stated maturity date. The higher

a bond’s credit quality, the greater the perceived chance that the issuer

will meet its payment obligations (and vice versa). Investment-grade

bonds are those whose credit quality is considered by independent bond

rating agencies, or through independent analysis conducted by an advisor,

to be sufficient to ensure timely payment of principal and interest under

current economic circumstances. Below investment-grade securities,

which include bonds commonly known as “junk bonds,” have lower credit

quality ratings.   

• Corporate Bonds are issued by businesses that want to borrow money for some purpose, often to develop a new product or service, to expand into a new market, or to buy another company. As with other types of bonds, the issuer promises to repay the principal on a specific date and to make interest payments in the meantime. The amount of interest offered depends both on market conditions and on the financial health of the corporation issuing the bonds. For example, companies with lower credit ratings generally need to offer a higher interest rate in order to obtain buyers for their bonds.

• U.S. Government and Agency Securities represent loans by investors to the U.S. Treasury or to a wide variety of government agencies and instrumentalities. Securities issued by the U.S. Treasury and a small number of U.S. government agencies (such as the Government National Mortgage Association) are backed by the full faith and credit of the U.S. government. However, securities issued by most U.S. government entities, including the U.S. government-sponsored enterprises discussed below, are neither guaranteed by the U.S. Treasury nor backed by the full faith and credit of the U.S. government. The market values of U.S. government and agency securities and U.S. Treasury securities are subject to fluctuation and to the expectation that the U.S. Treasury will be able to honor its obligations.
A number of government-sponsored enterprises, such as the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and the Federal Home Loan Banks, issue debt and mortgage-backed securities. Although government-sponsored enterprises may be chartered or sponsored by acts of Congress, they are not funded by congressional appropriations. For example, in September 2008, the U.S. Treasury placed the Federal National Mortgage Association and the Federal Home Loan Mortgage Corporation under conservatorship and appointed the Federal Housing Finance Agency to manage their daily operations. In addition, the U.S. Treasury entered into purchase agreements with the Federal National Mortgage Association and the Federal Home Loan Mortgage Corporation to provide them with capital in exchange for senior preferred stock. However, in general, a government-sponsored enterprise’s securities are neither issued nor guaranteed by the U.S. Treasury, and they are not backed by the full faith and credit of the U.S. government. In most cases, securities issued by a government-sponsored enterprise are supported only by the credit of the government-sponsored enterprise itself. In some cases, a government-sponsored enterprise’s securities may be supported by the ability of the government-sponsored enterprise to borrow from the U.S. Treasury or may be supported by the U.S. government in another way.

• Asset-Backed Securities represent a participation in, or are secured by and payable from, pools of underlying assets such as bank loans or credit card, automobile, or trade receivables. Asset-backed securities are issued by entities formed solely for the purpose of issuing such securities, and their value depends on repayments by underlying borrowers. The maturities of asset-backed securities are driven by borrowers’ prepayments, making them difficult to predict.

• Mortgage-Backed Securities represent partial ownership in pools of commercial or residential mortgage loans made by financial institutions to finance a borrower’s real estate purchase. These loans are packaged by private corporations (non-agency mortgage-backed securities) or government issuers (agency mortgage-backed securities) for sale to investors. As the underlying mortgage loans are paid by borrowers, the investors receive payments of interest and principal.
As discussed under U.S. Government and Agency Securities, most mortgage-backed securities issued by U.S. government entities or government-sponsored enterprises are neither guaranteed by the U.S. Treasury nor backed by the full faith and credit of the U.S. government. One exception is securities issued by the Government National Mortgage Association, which are backed by the full faith and credit of the U.S. government.

More on Fund Risks

More on Principal Risks

General Market Risk. The markets in which the Fund invests can be affected by a variety of factors. These factors, which can be real or perceived, may include economic, market, political, and regulatory conditions and developments as well as local, regional, or global events such as wars, military conflicts, natural disasters, and public health issues. In addition, investor sentiment and expectations regarding these factors can also impact the markets. Different parts of the market, including different industries and sectors as well as different types of securities, may react differently to factors that affect the market. These factors can contribute to market uncertainty, market volatility, and fluctuations in the value of the Fund’s investments, thereby resulting in potential losses to the Fund over short or long periods.

Investing in Equity Markets. The Fund invests in the equity markets. Equity markets have historically been cyclical, having periods of time when stock values rise and fall. These periods of rising and falling values can occur for unpredictable timeframes over the short and long term. Market volatility also is unpredictable and can lead to significant fluctuations in stock values, resulting in potential losses to the Fund.

Market Capitalization (Market Cap) — Large-Cap Companies. Large-cap companies are typically more well-established, well-known, and mature companies from an operational perspective than smaller cap companies. Because of this, they may not reach the same levels of growth or performance as smaller cap companies, and they may be slower to react to competitive challenges. The Fund’s focus on large-cap companies could affect its performance relative to a fund that is focused on a broader representation of the stock market.

Value Investing. Companies and their stock are often classified as growth or value. Growth investing and value investing are two investment styles used by advisors. Under certain market conditions these investment styles may perform differently, generating varying returns. The Fund’s approach to value investing could cause it to underperform other stock funds that use a different investment style. The Fund’s investments in value stocks are subject to the risk that the stocks’ valuations do not improve at the anticipated rate or that their returns do not move in tandem with the returns of other investment styles or the broader stock market.

Information Technology Sector. From time to time, stocks of companies within the information technology sector may make up a significant portion of the Fund’s investment portfolio. As a result, the Fund’s performance may be impacted by the general condition of the information technology sector. Companies in the information technology sector can be negatively affected by products becoming obsolete due to increased competition or short product life cycles, changing consumer preference, and/or expiring intellectual property rights, government scrutiny, changing regulations, and legal actions.

expose the bond markets in particular to heightened volatility and potential illiquidity. The degree to which the Fund is impacted by the following bond market risks may vary based on factors disclosed throughout this Prospectus, such as the types of bonds in which it invests and the overall credit quality, average maturity, and/or average duration of its bond holdings.

Interest Rate Risk. The Fund’s investments in bonds can be sensitive to interest rate changes and may be affected differently depending on the overall interest rate environment. During periods of rising interest rates, bond prices overall may decline, which could result in a decline in the Fund’s value. The prices of longer-term bonds are more sensitive to changes in interest rates than the prices of shorter-term bonds.

Income Risk. During periods of falling interest rates, the Fund’s income may decline because the Fund may have to invest new cash flow and cash from maturing bonds in bonds with lower yields. The income paid by shorter-term bonds is subject to a higher degree of fluctuation than the income paid by longer-term bonds.

Credit Risk. Credit risk refers to the chance that an issuer will default (fail to meet its credit obligations) or fail to make payments in a timely manner, which could result in a loss to the Fund. In addition, negative perceptions of an issuer’s ability to make payments can cause the price of a security to decline. The Fund could be impacted by factors negatively impacting the issuers of its corporate bond holdings. For example, if a company is restructured, there could be a substantial decline in the credit quality and market value of any bonds issued by that company. While all debt securities are subject to credit risk to some extent, those with higher credit quality ratings generally pose less credit risk than those with lower credit quality ratings.

Call Risk. Certain bonds held by the Fund may be callable. The issuer of a callable bond has the right to “call” (redeem) the bond before its maturity date. When a bond is called, the principal value of the bond is repaid earlier than anticipated (prepayment) and the investor (in this case, the Fund) no longer receives the interest payments that would have been paid up to the expected maturity date. In addition, bond calls and the resulting prepayments cause the Fund to lose any price appreciation that would have occurred between the time the bond was called and its original maturity date.

During periods of falling interest rates, it benefits issuers to call bonds with high interest rates. When this occurs, the Fund likely will be forced to reinvest the proceeds of any called bonds at a lower interest rate than that of the called bonds, resulting in a decline in the Fund’s income and a potential loss in the value of the Fund’s investments. If the Fund holds multiple callable bonds, frequent bond calls (as is likely during periods of falling interest rates) and the Fund’s subsequent reinvestment of the proceeds also would increase the Fund’s turnover rate.

Prepayment Risk. Certain bonds may be repaid in full prior to their maturity dates. Prepayment can be driven by bond calls (see Call Risk) or by borrowers repaying their debt earlier than anticipated (in the case of mortgage-backed, asset-backed, and similar debt securities such as collateralized mortgage obligations). In both cases, prepayment results in the principal value of a bond being repaid prior to its maturity date, resulting in fewer interest payments overall. Prepayments cause the investor (in this case, the Fund) to lose any price appreciation that would have occurred between the time the principal was paid in full and the original maturity date.

Prepayments occur more frequently in low interest rate environments. For example, during periods of falling interest rates, homeowners are more likely to refinance their mortgages, resulting in prepayment of mortgage-backed securities. Similarly, credit card holders are more likely to pay off their credit card bills, resulting in prepayment of asset-backed securities. As an investor in these securities, the Fund likely would be forced to reinvest the proceeds from any prepayments at a lower interest rate than when the prepaid bonds were purchased, resulting in a decline in the Fund’s income and a potential loss in the value of the Fund’s investments. In addition, frequent prepayments (as is likely during periods of falling interest rates) and the Fund’s subsequent reinvestment of the proceeds would increase the Fund’s turnover rate.

Extension Risk. During periods of rising interest rates, certain bonds held by the Fund may be paid off substantially more slowly than originally anticipated. As a result, the value of the bonds may fall, resulting in a decline in the Fund’s income and a potential loss in the value of the Fund’s investments. For example, investments in mortgage-backed securities are subject to the risk that homeowners will repay their mortgages more slowly than anticipated during periods of rising interest rates, which would extend the duration of mortgage-backed securities held by the Fund. The proceeds from such securities would then be unavailable to reinvest at higher interest rates.

to underperform relevant securities markets or other funds with a similar investment objective. All else being equal, actively managed funds can have higher fees and expenses than passively managed funds.

Additional Risks

Geopolitical and Sanctions Risk. Due to growing dependencies between global economies, geopolitical events can negatively affect all securities, markets, and economies. It is possible that events which only impact one geographic area could have negative short- or long-term effects on markets, issuers, and/or exchanges in the United States and other countries.

At times, the United States, other governments, or other supranational bodies (e.g., the United Nations) may impose sanctions on countries and/or entities in response to geopolitical events or other priorities. Compliance with sanctions could impact the Fund, including the Fund’s ability to transact in or obtain exposure to certain foreign securities and assets. Sanctions also could cause significant losses to the Fund’s investments and its performance could be negatively impacted. In lieu of sanctions, companies or specific goods that the company produces could be subjected to trade embargoes or tariffs, which can also affect securities markets and create volatility. So long as sanctions do not prohibit investment in the company or issuer, the Fund typically also would not be prohibited from investing in the affected company or issuer.

Potential Redemption Activity Impacts. The Vanguard funds can be negatively impacted by certain large redemptions. These redemptions could occur due to a single shareholder or multiple shareholders deciding to sell a large quantity of shares of a fund or a share class of the fund. Large redemptions can occur for many reasons, either as a result of actions taken by the Vanguard funds or their advisors, or as a result of events unrelated to actions taken by the Vanguard funds or their advisors. Actions taken by the Vanguard funds or their advisors could include, but are not limited to, changes to a fund’s advisor(s), changes to a fund’s portfolio manager(s), changes to the composition of a fund’s portfolio, and/or other product changes or launches that, for example, result in shareholders redeeming shares of one fund to purchase shares of another fund or investment vehicle. For a fund of funds, actions taken by the Vanguard funds or their advisors could include a withdrawal from an underlying fund or a change in the allocation to underlying funds. Events unrelated to actions taken by the Vanguard funds or their advisors could include shareholders selling out of a fund in response to market movements or regulatory changes.

holdings, which is a taxable event, could require the fund to distribute any corresponding capital gains or other taxable income to the fund’s remaining shareholders; see Distributions and Taxes in the Investing in Vanguard Funds section for additional information. The increased trading activity could also increase underlying costs for the fund due to commissions paid by the fund. When large redemptions occur, the Vanguard funds reserve the right to pay all or part of the redemptions in-kind and/or delay payment of the redemption proceeds for up to seven calendar days.

Investing in Derivatives. Investing in derivatives may present risks different from, and/or greater than, those associated with investing directly in stocks, bonds, or other types of investments. Derivatives could expose the Fund to increased volatility and/or significant loss. Certain derivatives have an inherent leverage component, providing the Fund exposure to a sizable position in an underlying asset with a relatively small upfront investment at the time the Fund enters into the derivatives position. For these derivatives, an adverse change in the value or price of the underlying asset could result in a loss substantially greater than the amount invested in the derivative itself. Some derivatives require the Fund to enter into a contract with a counterparty. If the counterparty is unable or unwilling to fulfill its contractual obligation, the Fund may experience a loss. A liquid market may not always exist for the Fund’s derivatives positions. The Fund may be unable to sell or otherwise exit its derivatives position at desired times or prices, which could also result in a loss to the Fund. Some derivatives, particularly OTC derivatives, can be complex and often are valued subjectively. Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them. Improper valuations can result in increased cash payment requirements to counterparties or a loss of value to the Fund.

Derivatives may not perform as intended, which may result in losses to the Fund. For example, derivatives used for hedging or as a substitute for a portfolio instrument may not provide the expected benefits, particularly during adverse market conditions. The use of derivatives is also subject to legal risk, which includes the risk of loss resulting from insufficient or unenforceable contractual documentation, insufficient capacity or authority of the Fund’s counterparty, and operational risk, which includes documentation or settlement issues, system failures, inadequate controls, and human error.

Vanguard provides investment advisory services to a fund. Ownership limitations restrict the amount that funds can invest in certain securities, due to either regulatory limits that apply to certain industries (for example, banking and utilities) or mechanisms that some issuers have in place to deter takeover attempts (for example, poison pills). These restrictions can have negative impacts on funds, including the inability of an index fund to track its index, the inability of a fund to meet its investment objectives, negative performance impacts, and unanticipated tax consequences. The impact of a particular ownership limitation on a Vanguard fund will vary based on several factors, including, but not limited to, a fund’s investment strategy and its current and desired exposure to limited securities, the industry to which the limitation applies, the country or region of a particular issuer, and the regulatory body imposing the limitation. In addition to the impacts of specific ownership limitations, the Vanguard funds are also subject to the risk of multiple ownership limitations applying at one time, which could increase the likelihood of a fund experiencing the negative impacts listed above. The Vanguard funds attempt to mitigate the impacts of ownership limitations through the various methods discussed below in “Methods to address ownership limitations.” However, it is possible that these methods will be unsuccessful and could also expose the Vanguard funds to other potential risks and negative consequences.

Impacts of Ownership Limitations. When an ownership limitation applies, the Vanguard funds may need to allocate ownership of impacted securities across impacted Vanguard funds, and a Vanguard fund may not be able to buy additional securities or continue to hold existing securities above its allocated amounts. For index funds, this can result in tracking error if a fund cannot buy or hold the securities it needs in order to replicate or sample its target index. For active funds, this can result in a fund not being able to take advantage of favorable opportunities to invest in securities that are subject to limitations. For both index and active funds, the inability to buy or hold securities could prevent a fund from being able to meet its investment objective or invest in accordance with its investment strategy, and/or could negatively impact the fund’s performance. In addition, the steps taken to address ownership limitations could result in additional costs and/or unanticipated tax consequences to a fund that affect the amount, timing, and character of distributions to the fund’s shareholders. The more assets the Vanguard funds hold, the more likely it is that ownership limitations will negatively impact Vanguard funds because they will not be able to purchase additional shares of limited securities above their allocated amounts in order to fully invest their assets in accordance with their investment strategies.

not always possible to secure relief and such relief could be revoked if the Vanguard funds are unable to satisfy the applicable conditions, or if the regulator or issuer changes its position or policy or if the applicable legal requirements become more restrictive. There is an increasing amount of uncertainty around how much ownership limitations relief regulators will grant to asset managers like Vanguard. Given this uncertainty, there is no guarantee that Vanguard or the Vanguard funds will be able to maintain their existing relief or obtain additional relief from ownership limitations in the future. A regulator may impose certain conditions on the Vanguard funds in connection with granting relief from an ownership limitation, including, for example, that the funds vote in a certain way with respect to shares of the limited security that the Vanguard funds hold in excess of the ownership limitation. Regulatory relief may also depend on the operational independence of certain Vanguard subsidiaries and/or business divisions.

In addition, the relief upon which Vanguard and the Vanguard funds currently rely, which has allowed Vanguard to exceed certain ownership limitations, could be reduced or revoked, forcing the Vanguard funds to sell down one or more securities to comply with the ownership limitations. If a fund has to sell securities, there could be negative impacts to fund performance as well as unanticipated tax consequences that could impact the amount, timing, and character of distributions to the fund’s shareholders.

When a Vanguard fund cannot buy or hold securities directly due to ownership limitations, the fund will typically try to get indirect exposure to impacted securities. The fund does this so that it can replicate as closely as possible the returns the fund would get if it directly owned the impacted securities. Indirect exposure can be accomplished through the use of derivatives, such as total return swaps, or by investing in wholly owned subsidiaries that hold the impacted securities. Both of these methods of obtaining indirect exposure increase fund costs, and, depending on the extent to which these alternatives are used by a fund to avoid exceeding ownership limits, the added costs could have a negative impact on the fund’s performance. With respect to an index fund, these added costs could also result in tracking error relative to the fund’s target index. The risks associated with derivatives use are discussed in more detail elsewhere in this Prospectus.

There is no guarantee that laws and regulations always will allow that indirect exposure to limited securities may be omitted for purposes of determining the Vanguard funds’ exposure to limited securities and compliance with the applicable ownership limitations. In such circumstances, the Vanguard funds could not use these techniques and would be required to sell down the indirect and/or direct holdings in the applicable limited securities.

Other Investment Policies

In addition to employing its principal investment strategies, the Fund may use the following other investment strategies and types of investments in order to achieve its investment objective.

Foreign Securities

Although the Fund typically does not make significant investments in foreign securities, it reserves the right to invest up to 25% of its assets in foreign securities, which may include depositary receipts. Foreign securities may be traded on U.S. or foreign markets.

Other Types of Investments

The Fund may invest in derivatives such as fixed income futures contracts, options, straddles, credit swaps, interest rate swaps, total return swaps, foreign currency exchange forward contracts, or other derivatives. In general, a derivative is a financial contract whose value is based on the value of a financial asset (such as a stock, a bond, or a currency), a physical asset (such as gold, oil, or wheat), a market index, or a reference rate. The Fund may use derivatives to obtain exposure to a stock, a basket of stocks, or an index. Derivatives may also be used as an alternate means to obtain economic exposure if the Fund is required to limit its investment in a particular issuer or industry. The Fund will not use derivatives for speculation or for the purpose of leveraging (magnifying) investment returns.

A foreign currency exchange forward contract is an agreement to buy or sell a currency at a specific price on a specific date, usually 30, 60, or 90 days in the future. In other words, the contract guarantees an exchange rate on a given date. Advisors of funds that invest in foreign securities can use these contracts to guard against unfavorable changes in currency rates. These contracts, however, would not prevent the Fund’s securities from falling in value as a result of risks other than unfavorable currency exchange movements. The Fund may use these contracts to manage currency exposure and to settle trades in a foreign currency.

The Fund may invest in cash equivalent investments (such as repurchase agreements) and securities that are convertible into common stocks. The Fund may also invest modestly in collateralized mortgage obligations (CMOs).

Cash Management

The Fund’s daily cash balance may be invested in one or more Vanguard CMT Funds, which are used as cash management vehicles for the Vanguard funds. When investing in a CMT Fund, the Fund bears its proportionate share of the expenses of the CMT Fund in which it invests. Vanguard receives no additional revenue from Fund assets invested in a CMT Fund.

Temporary Defensive Measures

The Fund may temporarily depart from its normal investment policies and strategies when an advisor believes that doing so is in the Fund’s best interest, so long as the strategy or policy employed is consistent with the Fund’s investment objective. For instance, the Fund may invest beyond its normal limits in derivatives or exchange-traded funds that are consistent with the Fund’s investment objective when those instruments are favorably priced or provide needed liquidity, as might be the case if the Fund is transitioning assets from one advisor to another or receives large cash flows that it cannot prudently invest immediately. The Fund may also invest beyond its normal limits in derivatives as an alternative means to obtain economic exposure if the Fund is required to limit its investment in a particular issuer or industry.

In addition, the Fund may take temporary defensive positions that are inconsistent with its normal investment policies and strategies—for instance, by allocating substantial assets to cash equivalent investments or other less volatile instruments—in response to adverse or unusual market, economic, political, or other conditions. In doing so, the Fund may succeed in avoiding losses but may otherwise fail to achieve its investment objective.

Cash equivalent investments include cash deposits, short-term bank deposits, and money market instruments such as U.S. Treasury bills and notes, bank certificates of deposit (CDs), repurchase agreements, commercial paper, and banker’s acceptances.

Portfolio Holdings

Please consult the Fund’s Statement of Additional Information or Vanguard’s website for a description of the policies and procedures that govern disclosure of the Fund’s portfolio holdings.

Management and Distribution of the Fund

The Fund is a member of The Vanguard Group, Inc. (Vanguard), a family of over 200 funds. All of the funds that are members of Vanguard (other than funds of funds) share in the expenses associated with administrative services and business operations, such as personnel, office space, and equipment.

Vanguard Marketing Corporation provides marketing services to the funds. Although fund shareholders do not pay sales commissions or 12b-1 distribution fees, each fund (other than a fund of funds) or each share class of a fund (in the case of a fund with multiple share classes) pays its allocated share of the Vanguard funds’ marketing costs.

How is Vanguard’s Corporate Structure Unique?

Vanguard is owned jointly by the funds it oversees and thus indirectly by

the shareholders in those funds. Most other mutual funds are operated by

management companies that are owned by third parties—either public or

private stockholders—and not by the funds they serve.

Investment Advisor

Wellington Management Company LLP, 280 Congress Street, Boston, MA 02210, a Delaware limited liability partnership, is an investment counseling firm that provides investment services to investment companies, employee benefit plans, endowments, foundations, and other institutions. Wellington Management and its predecessor organizations have provided investment advisory services for over 90 years. Wellington Management is owned by the partners of Wellington Management Group LLP, a Massachusetts limited liability partnership. As of December 31, 2025, Wellington Management and its investment advisory affiliates had investment management authority with respect to approximately $1.3 trillion in client assets. The firm manages the Fund subject to the supervision and oversight of Vanguard and the trustees and officers of the Fund.

The Fund pays the advisor a base fee plus or minus a performance adjustment. The base fee, which is paid quarterly, is a percentage of average daily net assets under management during the most recent fiscal quarter. The base fee has breakpoints, which means that the percentage declines as assets go up. The performance adjustment, also paid quarterly, is based on the cumulative total return of the Fund relative to that of the Composite Stock/Bond Index over the preceding 36-month period. The Index is a composite benchmark, weighted 65% in the S&P 500 Index and 35% in the Bloomberg U.S. Credit A or Better Bond Index. When the performance adjustment is positive, the Fund’s expenses increase; when it is negative, expenses decrease.

For the fiscal year ended December 31, 2025, the advisory fee represented an effective annual rate of 0.05% of the Fund’s average net assets before a performance-based decrease of 0.01%.

Board that an advisor be hired, terminated, or replaced or that the terms of an existing advisory agreement be revised. The Fund has filed an application seeking an SEC exemption with respect to investment advisors that are wholly owned subsidiaries of Vanguard. If the exemption is granted, the Fund may rely on the new SEC relief.

A discussion regarding the basis for the Board’s approval of the Fund’s investment advisory arrangement is available in the Fund’s Form N-CSR filed with the SEC for the fiscal year ended December 31 and in the applicable Financial Statements and Other Information document available on the Fund’s website.

The managers primarily responsible for the day-to-day management of the Fund are:

Loren L. Moran, CFA, Senior Managing Director and Fixed Income Portfolio Manager of Wellington Management. She has worked in investment management since 2006, has been with Wellington Management since 2014, and has managed the fixed income portion of the Fund since 2021 (co-managed since 2017). Education: B.S., Georgetown University.

Daniel J. Pozen, Senior Managing Director and Equity Portfolio Manager of Wellington Management. He has worked in investment management since 1999, has been with Wellington Management since 2006, and has managed the stock portion of the Fund since 2019. Education: B.A., Williams College; M.B.A., Dartmouth College (Tuck).

The Fund’s Statement of Additional Information provides information about each portfolio manager’s compensation, other accounts under management, and ownership of shares of the Fund.

Investing in Vanguard Funds

The Fund is offered exclusively to insurance company segregated accounts that serve as investment vehicles for variable life insurance and annuity contracts purchased by individuals. An individual investor cannot purchase shares of the Fund directly, but only through an annuity or life insurance contract offered by an insurance company. The prospectus for the annuity or life insurance program provided by the insurance company describes how individual investors (as contract owners) may elect the Fund as an investment option, allocate, transfer and withdraw amounts to, and from, separate accounts of insurance companies.

Purchase and Redemption of Fund Shares

The Fund offers its shares to insurance companies to fund both annuity and life insurance contracts. Because of differences in tax treatment or other considerations, the best interests of various contract owners participating in the Fund might at some time be in conflict. The Board will monitor for any material conflicts and determine what action, if any, should be taken.

If the Board determines that continued offering of shares would be detrimental to the best interests of the Fund’s shareholders, the Fund may suspend the offering of shares for a period of time. If the Board determines that a specific purchase acceptance would be detrimental to the best interests of the Fund’s shareholders (for example, because of the size of the purchase request or a history of frequent trading by the investor), the Fund may reject such a purchase request.

If you wish to redeem money from the Fund, please refer to the instructions provided in the prospectus for the annuity or life insurance program. Shares of the Fund may be redeemed on any business day that the New York Stock Exchange (“NYSE”) is open for trading. The redemption price of shares will be at the next-determined NAV per share. Redemption proceeds generally will be wired to the administrator within one business day following receipt of the redemption request, however, in certain circumstances, the settlement period may be longer. Contract owners will receive their redemption checks from the administrator.

Under normal circumstances, the Fund typically expects to meet redemptions with positive cash flows. When this is not an option, the Fund seeks to maintain its risk exposure by selling a cross section of its holdings to meet redemptions, while also factoring in transaction costs. Additionally, the Fund may work with the insurance companies through which contract owners participate in the Fund to implement redemptions in a manner that is least disruptive to the Fund.

Under certain circumstances, including under stressed market conditions, there are additional tools that the Fund may use in order to meet redemptions, including advancing the settlement of market trades with counterparties to match investor redemption payments or delaying settlement of an investor’s transaction to match trade settlement within regulatory requirements. The Fund may also suspend payment of redemption proceeds for up to seven days. Additionally, under these unusual circumstances, the Fund may borrow money (subject to certain regulatory conditions and if available under board-approved procedures) through an interfund lending facility; through a bank line-of-credit, including a joint committed credit facility; or through an uncommitted line-of-credit from Vanguard in order to meet redemption requests.

Although the Vanguard funds typically intend to meet redemption requests in cash, in consideration of the best interests of the funds and their remaining shareholders, the funds reserve the right to pay redemption proceeds wholly or partly in-kind by delivering readily marketable securities held by the funds in lieu of cash in conformity with applicable rules of the SEC and in accordance with procedures adopted by the funds’ boards of trustees. Redemptions in-kind may be used during both normal and stressed market conditions. A fund may delay payment of the redemption proceeds for up to seven calendar days.

The exchange privilege (your ability to redeem shares from one fund to purchase shares of another series of the Trust) may be available to you through your contract. Please refer to the prospectus for the annuity or life insurance program to check if the exchange privilege is available to you. Although we make every effort to maintain the exchange privilege, Vanguard reserves the right to revise or terminate this privilege, limit the amount of an exchange, or reject any exchange, at any time, without notice.

For certain categories of investors, the Fund has authorized one or more brokers to accept on its behalf purchase and redemption orders. The brokers are authorized to designate other intermediaries to accept purchase and redemption orders on the Fund’s behalf. The Fund will be deemed to have received a purchase or redemption order when an authorized broker, or a broker’s authorized designee, accepts the order in accordance with the Fund’s instructions. In most cases, for these categories of investors, a contract owner’s properly transmitted order will be priced at the Fund’s next-determined NAV after the order is accepted by the authorized broker or the broker’s designee. The contract owner should review the authorized broker’s policies relating to trading in the Vanguard funds.

Pricing of Fund Shares

Share Price, also known as net asset value (NAV), is typically calculated as of the close of regular trading on the New York Stock Exchange (“NYSE”), generally 4 p.m., Eastern time, on each day that the NYSE is open for business (a business day). In the rare event the NYSE experiences unanticipated disruptions and is unavailable at the close of the trading day, NAVs will be calculated as of the close of regular trading on the Nasdaq (or another alternate exchange if the Nasdaq is unavailable, as determined at Vanguard’s discretion), generally 4 p.m., Eastern time. On U.S. holidays or other days when the NYSE is closed, the NAV is not calculated, and the Vanguard funds do not sell or redeem shares. However, on those days the value of a fund’s assets may be affected to the extent that the fund holds securities that change in value on those days (such as foreign securities that trade on foreign markets that are open).

If a fund only has one share class, the NAV per share is computed by dividing the total assets, minus liabilities, of a fund by the number of fund shares outstanding. If a fund has more than one share class, each share class has its own NAV, which is computed by dividing the total assets, minus liabilities, allocated to the share class by the number of fund shares outstanding for that class. The value of securities and other investments held by the Vanguard funds is determined pursuant to the valuation policies and procedures adopted by the Vanguard funds’ boards of trustees. Vanguard has been designated as the valuation designee for the Vanguard funds pursuant to Rule 2a-5 under the Investment Company Act of 1940, subject to oversight by the Vanguard funds’ boards of trustees.

Securities for which market quotations are readily available are valued at their market value, based on quotations provided by independent third-party pricing sources. Such securities are generally valued at their official closing price, the last reported sales price, or if there were no sales that day, the mean between the closing bid and asking prices, from the principal exchange or market on which they are traded. A fund’s investments in any mutual fund shares, including institutional money market fund shares, are valued at the NAVs of the mutual fund shares. A fund’s investments in any ETF shares or closed-end fund shares are valued at the market value of those shares.

the owner might reasonably expect to receive upon the current sale of the security or other investment. Fair-value pricing may require subjective determinations. It is possible that the price determined through fair-value pricing may differ from the price quoted or published by other sources and may not be the price at which those investments could have been sold during the period in which the fair value was used.

Fair-value pricing may be used in a variety of circumstances. For example, it may be used if the value of a security or other investment has been materially affected by events occurring after the close of the principal exchange or market on which the security is traded but before the funds’ NAV is calculated. These events might be company-specific (e.g., earnings report, merger announcement), country-specific (e.g., significant price movements in U.S. or a foreign market), or regional/global events (e.g., natural disaster, economic or political news, interest rate change, act of terrorism). These events could affect a single security or a large number of securities in a particular market, and it most commonly occurs with foreign portfolio holdings because many foreign markets operate at times that do not coincide with those of the major U.S. markets. Events that could affect the value of the foreign portfolio holdings may occur between the close of the foreign market and the time a fund’s NAV is calculated. The values of any foreign securities held by a fund are converted into U.S. dollars using an exchange rate obtained from an independent third party as of the close of regular trading on the NYSE.

In addition, fair-value pricing may be used if trading in a security is halted and does not resume before a fund’s pricing time, a security does not trade in the course of a day and a fund holds enough of the security that its price could affect the NAV, or if the trading market on which a security is listed is suspended or closed and no appropriate alternative trading market is available.

Fixed income securities are generally valued based on information furnished by independent pricing services and are priced at fair value. Pricing services may use matrix pricing or valuation models that utilize certain inputs and assumptions to derive values. Pricing services generally value fixed income securities assuming orderly transactions of an institutional round lot size, but a fund may hold or transact in such securities in smaller odd lot sizes. Odd lots may trade at lower prices than institutional round lots.

Failures by third-party pricing services to carry out their obligations to the Vanguard funds (e.g., any errors in the data provided by third-party pricing services) could result in delays in the calculation of the funds’ NAVs and/or the inability to calculate the NAVs over extended time periods. The funds may be unable to recover any losses associated with such failures.

The Vanguard funds have authorized certain financial intermediaries and their designees, and may, from time to time, authorize certain funds of funds for which Vanguard serves as the investment advisor (Vanguard Funds of Funds), to accept orders to purchase or redeem fund shares on behalf of the Vanguard funds. In these circumstances, the Vanguard fund will be deemed to receive an order when accepted by the authorized financial intermediary, its designee, or one of the Vanguard Funds of Funds, and the order will be executed using the NAV next calculated after such acceptance.

The Fund’s NAV is used to determine the unit value for the annuity or life insurance program through which you invest. For more information on unit values, please refer to the prospectus of the insurance company that offers your annuity or life insurance program.

Distributions and Taxes

The Fund normally distributes its net investment income and net realized short-term or long-term capital gains, if any, to its shareholders, which are the insurance company separate accounts that fund your variable annuity or variable life insurance contract. The Fund may also make distributions that are treated as a return of capital. As an owner of an annuity or life insurance contract, the tax consequences to you of your investment in the Fund depend on the provisions of the annuity or life insurance contract through which you invest; please refer to the prospectus of such contract for more information. As a contract owner, you should consult your own tax professional for information regarding the particular situation and the possible application of U.S. federal, state, local, foreign, and other taxes.

The Fund intends to operate in such a manner that a separate account investing only in Fund shares will result in the variable annuity and variable life insurance contracts supported by that account receiving favorable tax treatment. This favorable treatment means that, as a contract owner, you generally will not be taxed on Fund distributions or proceeds on dispositions of Fund shares received by the separate account funding your contract. However, in order to qualify for this favorable treatment, the insurance company separate accounts that invest in the Fund must satisfy certain requirements. If the Fund funding your contract does not meet such requirements, your contract could lose its favorable tax treatment and income and gain allocable to your contract could be taxable to you. Also, if the IRS were to determine that the contract owners have an impermissible level of control over the investments funding their contracts, your contract could lose its favorable tax treatment, and income and gain allocable to your contract could be taxable to you. Please see the Fund’s Statement of Additional Information for more information.

From time to time, Vanguard and/or a fund’s board of trustees may adjust a fund’s fees and expenses and/or reduce, refund, reimburse, waive, or otherwise return to the funds and their shareholders a portion of prior fees and expenses (collectively, “expense adjustments”). Fund performance and potentially shareholder distributions, will reflect such expense adjustments. If you sell all or part of your investment in a fund before an expense adjustment occurs, then you will not receive the economic benefit, if any, of such expense adjustment. An expense adjustment at any given time does not imply or guarantee that similar or additional expense adjustments will be made in the future.

Frequent Trading Limitations

Some investors may try to profit from strategies involving frequent trading of mutual fund shares (such as market-timing) and other excessive trading practices (together, “frequent trading”). For funds holding foreign securities, investors may try to take advantage of an anticipated difference between the price of the fund’s shares and price movements in overseas markets because of different closing times of U.S. and non-U.S. markets, a practice also known as time-zone arbitrage. Some investors may also try to engage in frequent trading of funds holding investments in small-cap stocks and high-yield bonds that are thinly traded. Frequent trading may disrupt portfolio management strategies and increase a fund’s costs (such as increased brokerage and administrative costs) for all shareholders including the long-term investors.  

Each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) limits frequent trading. The board of trustees of each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) has adopted policies and procedures reasonably designed to detect and discourage frequent trading. Although there is no assurance that Vanguard will be able to detect or prevent frequent trading in all circumstances, the policies and procedures discussed below have been adopted to address these issues.

Each Vanguard fund reserves the right to reject any purchase request—including exchanges from other Vanguard funds—without notice and regardless of size. For example, a purchase request could be rejected because the investor has a history of frequent trading or if Vanguard determines that such purchase may negatively affect a fund’s operation or performance. Certain Vanguard funds charge shareholders purchase and/or redemption fees on transactions. Each Vanguard fund (other than retail and government money market funds), in determining its net asset value, will use fair-value pricing when appropriate, as described in Pricing of Fund Shares. Fair-value pricing may reduce or eliminate the profitability of certain frequent trading strategies. 

You may purchase or sell Fund shares through a contract offered by an insurance company. When insurance companies establish omnibus accounts in the Fund for their clients, we cannot monitor the individual clients’ trading activity. However, we review trading activity at the omnibus account level, and we look for activity that may indicate potential frequent trading. If we detect suspicious trading activity, we will seek the assistance of the insurance company to investigate that trading activity and take appropriate action, including prohibiting additional purchases of Fund shares by a client. Insurance companies may apply frequent-trading policies that differ from one another. Please read the insurance company contract and program materials carefully to learn of any rules or fees that may apply.

See the prospectus for the annuity or insurance program through which Fund shares are offered for further details on transaction policies.

Do not invest with Vanguard if you are a market-timer.

Financial Highlights

Financial highlights information is intended to help you understand a fund’s performance for the past five years (or, if shorter, its period of operations). Certain information reflects financial results for a single fund share. Total return represents the rate that an investor would have earned or lost each period on an investment in a fund or share class (assuming reinvestment of all distributions). This information has been obtained from the financial statements audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report, along with fund financial statements, is included in a fund’s most recent annual Financial Statements and Other Information. You may obtain a free copy of a fund’s latest disclosure documents upon request.

Yields and total returns presented for the Fund are net of the Fund’s operating expenses, but they do not take into account charges and expenses attributable to the annuity or life insurance program through which you invest. The expenses of the annuity or life insurance program reduce the returns and yields you ultimately receive, so you should bear those expenses in mind when evaluating the performance of the Fund and when comparing the yields and returns of the Fund with those of other mutual funds.

Vanguard Balanced Portfolio

For a Share Outstanding Throughout Each Period	Year Ended December 31,
For a Share Outstanding Throughout Each Period	2025	2024	2023	2022	2021
Net Asset Value, Beginning of Period	$24.77	$23.29	$21.72	$28.41	$25.68
Investment Operations
Net Investment Income1	.530	.534	.518	.471	.468
Net Realized and Unrealized Gain (Loss) on Investments	3.000	2.752	2.415	(4.277)	4.137
Total from Investment Operations	3.530	3.286	2.933	(3.806)	4.605
Distributions
Dividends from Net Investment Income	(.547)	(.571)	(.464)	(.480)	(.497)
Distributions from Realized Capital Gains	(2.343)	(1.235)	(.899)	(2.404)	(1.378)
Total Distributions	(2.890)	(1.806)	(1.363)	(2.884)	(1.875)
Net Asset Value, End of Period	$25.41	$24.77	$23.29	$21.72	$28.41
Total Return	16.46%	14.80%	14.33%	-14.30%	19.02%
Ratios/Supplemental Data
Net Assets, End of Period (Millions)	$3,820	$3,535	$3,260	$3,142	$3,787
Ratio of Total Expenses to Average Net Assets2	0.20%3	0.20%4	0.21%4	0.21%4	0.20%
Ratio of Net Investment Income to Average Net Assets	2.22%	2.25%	2.37%	2.05%	1.76%
Portfolio Turnover Rate5	68%	64%	40%	40%	33%

1	Calculated based on average shares outstanding.
2	Includes performance-based investment advisory fee increases (decreases) of (0.01%), (0.01%), (0.00%), 0.00%, and (0.01%).
3	The ratio of expenses to average net assets for the period net of reduction from broker commission abatement arrangements was 0.20%.
4	The ratio of expenses to average net assets for the period net of reduction from custody fee offset and broker commission abatement arrangements was 0.20%, 0.21% and 0.21%, respectively.
5	Includes 0%, 1%, 1%, 7%, and 1%, respectively, attributable to mortgage-dollar-roll activity.

Additional Information

A Precautionary Note to Investment Companies. The Fund’s shares are issued by a registered investment company, and therefore the acquisition of such shares by other investment companies and private funds is subject to the restrictions of Section 12(d)(1) of the Investment Company Act of 1940 (the 1940 Act). SEC Rule 12d1-4 under the 1940 Act permits registered investment companies to invest in other registered investment companies beyond the limits in Section 12(d)(1), subject to certain conditions, including that funds with different investment advisors must enter into a fund of funds investment agreement.

Forum Selection. The Trust’s Bylaws designate Delaware courts as the exclusive forum for certain claims against or related to the Trust, a trustee, an officer, or other employee of the Trust, except that, unless the Trust otherwise consents in writing, the U.S. Federal District Courts are the exclusive forum for the resolution of complaints under the Securities Act of 1933 or the 1940 Act. These provisions may limit a shareholder’s ability to bring a claim in a different forum and may result in increased shareholder costs in pursuing such a claim.

Shareholder Rights. The Fund’s Agreement and Declaration of Trust, as amended, requires a shareholder bringing a derivative action on behalf of the Trust that is subject to a pre-suit demand to collectively hold at least 10% of the outstanding shares of the Trust or at least 10% of the outstanding shares of the series or class to which the demand relates and to undertake to reimburse the Trust for the expense of any counsel or advisors used when considering the merits of the demand in the event that the board of trustees determines not to bring such action. In each case, these requirements do not apply to claims arising under the federal securities laws to the extent that any such federal securities laws, rules, or regulations do not permit such application. The Trust’s Bylaws also provide that shareholders waive the right to trial by jury to the fullest extent permitted by law.

Joint Committed Credit Facility. The Fund participates, along with other funds managed by Vanguard, in a committed credit facility provided by a syndicate of lenders pursuant to a credit agreement that may be renewed annually; each Vanguard fund is individually liable for its borrowings, if any, under the credit facility. The amount and terms of the committed credit facility are subject to approval by the Board and renegotiation with the lender syndicate on an annual basis.

Inception Date. The date on which the assets of a fund are first invested in accordance with the fund’s investment objective. For funds with a subscription period, the inception date is the day after that period ends. Investment performance is generally measured from the inception date.

Securities Market Indexes
Listed below are the broad-based securities market indexes, as referenced in the Fund’s Average Annual Total Returns table:

Bloomberg U.S. Aggregate Bond Index. An index that is the broadest measure of the taxable U.S. bond market, including most U.S. Treasury, agency, corporate, mortgage-backed, asset-backed, and international dollar-denominated issues, all with investment-grade ratings (rated Baa3 or above by Moody’s) and maturities of 1 year or more.

Dow Jones U.S. Total Stock Market Float Adjusted Index. An index designed to measure all U.S. equity issues with readily available prices.

CFA® is a registered trademark owned by CFA Institute.

“Bloomberg®” and Bloomberg U.S. Aggregate Bond Index (the “Index”) are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited (“BISL”), the administrator of the index (collectively, “Bloomberg”), and have been licensed for use for certain purposes by Vanguard.

Vanguard Variable Insurance Funds Balanced Portfolio (the “Fund”) is not sponsored, endorsed, sold or promoted by Bloomberg. Bloomberg does not make any representation or warranty, express or implied, to the owners of or counterparties to the Fund or any member of the public regarding the advisability of investing in securities or commodities generally or in the Fund particularly. The only relationship of Bloomberg to Vanguard is the licensing of certain trademarks, trade names and service marks and of the Index, which are determined, composed and calculated by BISL without regard to Vanguard or the Fund. Bloomberg has no obligation to take the needs of Vanguard or the owners of the Fund into consideration in determining, composing or calculating the Index. Bloomberg is not responsible for and has not participated in the determination of the timing, price, or quantities of the Fund to be issued. Bloomberg shall not have any obligation or liability, including, without limitation, to customers of the Fund, in connection with the administration, marketing or trading of the Fund.

BLOOMBERG DOES NOT GUARANTEE THE ACCURACY AND/OR THE COMPLETENESS OF THE INDEX OR ANY DATA RELATED THERETO AND SHALL HAVE NO LIABILITY FOR ANY ERRORS, OMISSIONS OR INTERRUPTIONS THEREIN. BLOOMBERG DOES NOT MAKE ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY VANGUARD, OWNERS OF THE FUND OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE INDEX OR ANY DATA RELATED THERETO. BLOOMBERG DOES NOT MAKE ANY EXPRESS OR IMPLIED WARRANTIES AND EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE INDEX OR ANY DATA RELATED THERETO. WITHOUT LIMITING ANY OF THE FOREGOING, TO THE MAXIMUM EXTENT ALLOWED BY LAW, BLOOMBERG, ITS LICENSORS, AND ITS AND THEIR RESPECTIVE EMPLOYEES, CONTRACTORS, AGENTS, SUPPLIERS, AND VENDORS SHALL HAVE NO LIABILITY OR RESPONSIBILITY WHATSOEVER FOR ANY INJURY OR DAMAGES—WHETHER DIRECT, INDIRECT, CONSEQUENTIAL, INCIDENTAL, PUNITIVE OR OTHERWISE—ARISING IN CONNECTION WITH THE FUND OR INDEX OR ANY DATA OR VALUES RELATING THERETO—WHETHER ARISING FROM THEIR NEGLIGENCE OR OTHERWISE, EVEN IF NOTIFIED OF THE POSSIBILITY THEREOF.

Connect with Vanguard® ˃ vanguard.com

For More Information

If you would like more information about Vanguard Variable Insurance Funds Balanced Portfolio, the following documents are available free upon request:

Annual/Semiannual Reports to Shareholders and Form N-CSR

Additional information about the Fund’s investments is available in the Fund’s annual and semiannual reports to shareholders and in Form N-CSR. In the annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Fund’s performance during its last fiscal year. In Form N-CSR, you will find the Fund’s annual and semiannual financial statements.

Statement of Additional Information (SAI)

The SAI provides more detailed information about the Fund and is incorporated by reference into (and thus legally a part of) this Prospectus.

To obtain a free copy of the latest annual or semiannual reports, financial statements, or the SAI, or to request additional information about the Fund or other Vanguard funds, please visit https://vgi.vg/fund-literature or contact us as follows:

Telephone: 800-522-5555; Text telephone for people with hearing impairment: 800-749-7273

Information Provided by the SEC

Reports and other information about the Fund are available in the EDGAR database on the SEC’s website at sec.gov, or you can receive copies of this information, for a fee, by electronic request at the following email address: publicinfo@sec.gov.

Fund’s Investment Company Act file number: 811-05962

Vanguard Marketing Corporation, Distributor.

P 106 042026

April 28, 2026

Prospectus

Vanguard Variable Insurance Funds

Capital Growth Portfolio

This Prospectus contains financial data for the Fund through the fiscal year ended December 31, 2025.

The Securities and Exchange Commission (SEC) has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

Contents

Fund Summary	1
More on the Fund	6
Investment Objective and More on Principal Investment Strategies	6
More on Fund Risks	9
Other Investment Policies	14
Portfolio Holdings	16
Management and Distribution of the Fund	16
Investing in Vanguard Funds	19
Purchase and Redemption of Fund Shares	19
Pricing of Fund Shares	21
Distributions and Taxes	23
Frequent Trading Limitations	24
Financial Highlights	26
Additional Information	28

Fund Summary

Investment Objective

Vanguard Variable Insurance Funds Capital Growth Portfolio (the “Fund”) seeks to provide long-term capital appreciation.

Fees and Expenses

Annual Fund Operating Expenses
(Expenses that you pay each year as a percentage of the value of your investment)


Management Fees	0.33 %
12b-1 Distribution Fee	None
Other Expenses	0.01 %
Total Annual Fund Operating Expenses	0.34 %

Example

1 Year	3 Years	5 Years	10 Years
$35	$109	$191	$431

Portfolio Turnover

Principal Investment Strategies

The Fund employs an active management approach, investing in stocks considered to have above-average earnings growth potential that is not reflected in their current market prices. The Fund’s portfolio consists predominantly of large- and mid-capitalization stocks.

Principal Risks

• Growth Investing. The Fund’s approach to growth investing could cause it to underperform other stock funds that use a different investment style. Growth stocks typically produce lower yields because growth companies prefer to reinvest earnings into research and development to promote growth and increase profitability. Research and development can be expensive and may not always produce favorable results, which could harm a company’s performance relative to the broader market.

• Health Care Sector. From time to time, stocks of companies within the health care sector may make up a significant portion of the Fund’s investment portfolio. As a result, the Fund’s performance may be impacted by the general condition of the health care sector.

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

Annual Total Returns

Annual Total Returns — Capital Growth Portfolio

During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were:

	Total Return	Quarter
Highest	17.13 %	June 30, 2020
Lowest	-19.45 %	March 31, 2020

Average Annual Total Returns for Periods Ended December 31, 2025

	1 Year	5 Years	10 Years
Capital Growth Portfolio	28.98 %	13.97 %	14.96 %
Standard & Poor’s 500 Index (reflects no deduction for fees, expenses, or taxes)	17.88 %	14.42 %	14.82 %
Dow Jones U.S. Total Stock Market Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	17.05	13.07	14.21

Investment Advisor

PRIMECAP Management Company (PRIMECAP)

Portfolio Managers

Theo A. Kolokotrones, Chairman Emeritus of PRIMECAP. He has co-managed the Fund since its inception in 2002.

Joel P. Fried, Chairman of PRIMECAP. He has co-managed the Fund since its inception in 2002.

Alfred W. Mordecai, President of PRIMECAP. He has co-managed the Fund since its inception in 2002.

M. Mohsin Ansari, Vice Chairman of PRIMECAP. He has co-managed the Fund since 2007.

James M. Marchetti, Executive Vice President of PRIMECAP. He has co-managed the Fund since 2015.

Purchase and Sale of Fund Shares

Tax Information

Payments to Financial Intermediaries

The Fund and its advisor do not pay financial intermediaries for sales of Fund shares.

More on the Fund

This Prospectus provides information about Vanguard Variable Insurance Funds Capital Growth Portfolio, a series of Vanguard Variable Insurance Funds (the “Trust”). Reading this Prospectus will help you decide whether the Fund is the right investment for you. The Fund is a mutual fund used solely as an investment option for annuity or life insurance contracts offered by insurance companies. This means that you cannot purchase shares of the Fund directly, but only through an annuity or life insurance contract offered by an insurance company. The Fund is separate from other Vanguard mutual funds, even when the Fund and a Vanguard mutual fund have the same investment objective and advisor. The Fund’s investment performance will differ from the performance of other Vanguard funds because of differences in the securities held and because of administrative and insurance costs associated with the annuity or life insurance program through which you invest.

Investment Objective and More on Principal Investment Strategies

Investment Objective

The Fund seeks to provide long-term capital appreciation.

The Fund’s investment objective is fundamental and may not be materially changed without shareholder approval.

Implementation of Investment Objective

The Fund’s advisor seeks to achieve the Fund’s investment objective by mainly investing in common stocks of companies that the advisor believes have favorable prospects for capital appreciation and that sell at attractive prices but typically produce little current income. The Fund’s portfolio consists predominantly of large- and mid-capitalization stocks.

What is Active Management?

Actively managed funds typically seek to exceed the average returns of a

particular financial market or market segment. The Fund’s advisor will

select securities to buy and sell based on the advisor’s judgments about

companies and their financial prospects, the prices of the securities, and

the markets and the economy in general. In selecting securities, an

advisor may rely on, among other things, research, market forecasts,

quantitative models, and their own judgment and experience.

Security Selection

The Fund’s advisor selects common stocks that it believes have above-average earnings growth potential that is not reflected in the current market price. Companies selected for stock purchases typically have strong positions within their industries, increasing sales, improving profitability, good long-term prospects for above-average growth in earnings, and strong management teams.

The advisor attempts to quantify a company’s “fundamental value,” which is the advisor’s estimate of the financial value of the company. The advisor compares the fundamental value with the market price of the company’s stock and then decides whether to purchase the stock mainly on the basis of how attractive its market price is in relation to its fundamental value. Although the Fund invests with a long-term horizon of three to five years, the advisor may sell a stock if its market price appears to have risen above its fundamental value, if other securities appear to be more favorably priced, or if the reasons for which the stock was purchased no longer hold true.

The advisor does not try to make investment decisions based on short-term trends in the stock market. If attractively priced stocks cannot be found, the Fund’s cash levels will increase. Because the advisor’s selections are determined by an analysis of each individual stock, the Fund’s makeup may differ substantially from the overall market’s characteristics. For example, the proportion of the Fund’s assets invested in a particular industry may be significantly larger or smaller than that industry’s representation in the overall stock market.

Vanguard Fund	Asset-Weighted Median Market Capitalization
Capital Growth Portfolio	$184 billion

Additional Information Regarding the Fund’s Investments

The Fund’s investments are described in more detail below.

• Growth Stocks typically represent companies that are expected to deliver above-average increases in revenue, earnings, cash flow, or other similar criteria. These stocks typically reinvest profits into the business rather than paying dividends, which results in low or no dividend yields. Growth stocks often trade at higher valuations relative to financial metrics like price-to-earnings or book value, as their prices are largely based on projections of future performance.

• Mid-Cap Stocks represent medium-sized companies, which can be companies that are more established than small-cap companies but do not have the market share of large-cap companies. These companies may be more agile than large-cap companies in responding to market changes, while also benefiting from more resources and operational maturity than small-cap companies. However, they can still face challenges during economic downturns.

More on Fund Risks

More on Principal Risks

Market Capitalization (Market Cap) — Mid-Cap Companies. Mid-cap companies fall between large- and small-cap companies in size. Due to being smaller, they may be more affected by adverse business or economic events than larger companies. The Fund’s focus on mid-cap companies could affect its performance relative to a fund that is focused on a broader representation of the stock market.

differently, generating varying returns. The Fund’s approach to growth investing could cause it to underperform other stock funds that use a different investment style. Growth stocks typically produce lower yields because growth companies prefer to reinvest earnings into research and development to promote growth and increase profitability. Research and development can be expensive and may not always produce favorable results, which could harm a company’s performance relative to the broader market.

Active Management. The Fund is actively managed. Active management permits the advisor to use reasonable discretion on how to invest the assets of the Fund in a manner that helps the advisor achieve the strategy of the Fund. The advisor’s security selection and/or strategy execution could cause the Fund to underperform relevant securities markets or other funds with a similar investment objective. All else being equal, actively managed funds can have higher fees and expenses than passively managed funds.

Health Care Sector. From time to time, stocks of companies within the health care sector may make up a significant portion of the Fund’s investment portfolio. As a result, the Fund’s performance may be impacted by the general condition of the health care sector. Companies in the health care sector can be negatively affected by rising costs of medical products and services, the rapid speed at which many health care products and services become obsolete, the possibility that regulatory approvals (which often entail lengthy application and testing procedures) will not be granted for new drugs and medical products, labor shortages, litigation and product liability claims, research and development, patent protection and expiring patents, government regulation, and restrictions on government reimbursement for medical expenses.

Additional Risks

A large redemption could adversely affect a fund’s liquidity and NAV. For example, a large redemption could require a fund’s manager to sell portfolio holdings at unplanned or inopportune times. The manager’s sale of these holdings, which is a taxable event, could require the fund to distribute any corresponding capital gains or other taxable income to the fund’s remaining shareholders; see Distributions and Taxes in the Investing in Vanguard Funds section for additional information. The increased trading activity could also increase underlying costs for the fund due to commissions paid by the fund. When large redemptions occur, the Vanguard funds reserve the right to pay all or part of the redemptions in-kind and/or delay payment of the redemption proceeds for up to seven calendar days.

leverage component, providing the Fund exposure to a sizable position in an underlying asset with a relatively small upfront investment at the time the Fund enters into the derivatives position. For these derivatives, an adverse change in the value or price of the underlying asset could result in a loss substantially greater than the amount invested in the derivative itself. Some derivatives require the Fund to enter into a contract with a counterparty. If the counterparty is unable or unwilling to fulfill its contractual obligation, the Fund may experience a loss. A liquid market may not always exist for the Fund’s derivatives positions. The Fund may be unable to sell or otherwise exit its derivatives position at desired times or prices, which could also result in a loss to the Fund. Some derivatives, particularly OTC derivatives, can be complex and often are valued subjectively. Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them. Improper valuations can result in increased cash payment requirements to counterparties or a loss of value to the Fund.

Ownership Limitations Risk. As the Vanguard funds continue to grow, they may be increasingly impacted by ownership limitations that apply to certain securities held by the Vanguard funds (“limited securities”). An ownership limitation restricts the amount of a security that funds within the same fund complex or funds advised by the same investment advisor can own. These limitations may apply even where an external manager or different affiliate of Vanguard provides investment advisory services to a fund. Ownership limitations restrict the amount that funds can invest in certain securities, due to either regulatory limits that apply to certain industries (for example, banking and utilities) or mechanisms that some issuers have in place to deter takeover attempts (for example, poison pills). These restrictions can have negative impacts on funds, including the inability of an index fund to track its index, the inability of a fund to meet its investment objectives, negative performance impacts, and unanticipated tax consequences. The impact of a particular ownership limitation on a Vanguard fund will vary based on several factors, including, but not limited to, a fund’s investment strategy and its current and desired exposure to limited securities, the industry to which the limitation applies, the country or region of a particular issuer, and the regulatory body imposing the limitation. In addition to the impacts of specific ownership limitations, the Vanguard funds are also subject to the risk of multiple ownership

limitations applying at one time, which could increase the likelihood of a fund experiencing the negative impacts listed above. The Vanguard funds attempt to mitigate the impacts of ownership limitations through the various methods discussed below in “Methods to address ownership limitations.” However, it is possible that these methods will be unsuccessful and could also expose the Vanguard funds to other potential risks and negative consequences.

Methods to Address Ownership Limitations. The Vanguard funds try to manage the negative impacts of these ownership limitations on the Vanguard funds by seeking permission (relief) from regulators and/or issuers to purchase or hold more securities than the amount allowed by ownership limitations. However, it is not always possible to secure relief and such relief could be revoked if the Vanguard funds are unable to satisfy the applicable conditions, or if the regulator or issuer changes its position or policy or if the applicable legal requirements become more restrictive. There is an increasing amount of uncertainty around how much ownership limitations relief regulators will grant to asset managers like Vanguard. Given this uncertainty, there is no guarantee that Vanguard or the Vanguard funds will be able to maintain their existing relief or obtain additional relief from ownership limitations in the future. A regulator may impose certain conditions on the Vanguard funds in connection with granting relief from an ownership limitation, including, for example, that the funds vote in a certain way with respect to shares of the limited security that the Vanguard funds hold in excess of the ownership limitation. Regulatory relief may also depend on the operational independence of certain Vanguard subsidiaries and/or business divisions.

Other Investment Policies

In addition to employing its principal investment strategies, the Fund may use the following other investment strategies and types of investments in order to achieve its investment objective.

Foreign Securities

Other Types of Investments

oil, or wheat), a market index, or a reference rate. The Fund may use derivatives to obtain exposure to a stock, a basket of stocks, or an index. Derivatives may also be used as an alternate means to obtain economic exposure if the Fund is required to limit its investment in a particular issuer or industry. The Fund will not use derivatives for speculation or for the purpose of leveraging (magnifying) investment returns.

A foreign currency exchange forward contract is an agreement to buy or sell a currency at a specific price on a specific date, usually 30, 60, or 90 days in the future. In other words, the contract guarantees an exchange rate on a given date. Advisors of funds that invest in foreign securities can use these contracts to guard against unfavorable changes in currency exchange rates. These contracts, however, would not prevent the Fund’s securities from falling in value as a result of risks other than unfavorable currency exchange movements.

Cash Management

Temporary Defensive Measures

The Fund may temporarily depart from its normal investment policies and strategies when the advisor believes that doing so is in the Fund’s best interest, so long as the strategy or policy employed is consistent with the Fund’s investment objective. For instance, the Fund may invest beyond its normal limits in derivatives or exchange-traded funds that are consistent with the Fund’s investment objective when those instruments are favorably priced or provide needed liquidity, as might be the case if the Fund is transitioning assets from one advisor to another or receives large cash flows that it cannot prudently invest immediately. The Fund may also invest beyond its normal limits in derivatives as an alternative means to obtain economic exposure if the Fund is required to limit its investment in a particular issuer or industry.

Portfolio Holdings

Please consult the Fund’s Statement of Additional Information or Vanguard’s website for a description of the policies and procedures that govern disclosure of the Fund’s portfolio holdings.

Management and Distribution of the Fund

How is Vanguard’s Corporate Structure Unique?

Vanguard is owned jointly by the funds it oversees and thus indirectly by

the shareholders in those funds. Most other mutual funds are operated by

management companies that are owned by third parties—either public or

private stockholders—and not by the funds they serve.

Investment Advisor

PRIMECAP Management Company, 177 East Colorado Blvd., 11th Floor, Pasadena, CA 91105, advisor to the Fund, is an investment advisory firm founded in 1983. PRIMECAP also provides investment advisory services to endowment funds, employee benefit plans, mutual funds, foundations, and other institutional clients unrelated to Vanguard. As of December 31, 2025, PRIMECAP managed approximately $139 Billion in assets. The firm manages the Fund subject to the supervision and oversight of Vanguard and the trustees and officers of the Fund.

The Fund pays the advisor a base fee plus or minus a performance adjustment. The base fee, which is paid quarterly, is a percentage of average daily net assets under management during the most recent fiscal quarter. The performance adjustment, also paid quarterly, is based on the cumulative total return of the Fund relative to that of the S&P 500 Index over the preceding 36-month period. When the performance adjustment is positive, the Fund’s expenses increase; when it is negative, expenses decrease.

For the fiscal year ended December 31, 2025, the advisory fee paid to PRIMECAP represented an effective annual rate of 0.15% of the Fund’s average net assets.

Under the terms of an SEC exemption, the Board may, without prior approval from shareholders, change the terms of an advisory agreement with a third-party investment advisor or hire a new third-party investment advisor—either as a replacement for an existing advisor or as an additional advisor. Any significant change in the Fund’s advisory arrangement will be communicated to shareholders in writing. As Vanguard is the Fund’s sponsor and overall manager, Vanguard, through its wholly owned subsidiary Vanguard Portfolio Management (VPM), may provide investment advisory services to the Fund under certain circumstances. Vanguard may also recommend to the Board that an advisor be hired, terminated, or replaced or that the terms of an existing advisory agreement be revised. The Fund has filed an application seeking an SEC exemption with respect to investment advisors that are wholly owned subsidiaries of Vanguard. If the exemption is granted, the Fund may rely on the new SEC relief.

The managers primarily responsible for the day-to-day management of the Fund are:

Theo A. Kolokotrones, Chairman Emeritus of PRIMECAP. He has worked in investment management since 1970, has managed assets since 1979, has been with PRIMECAP since 1983, and has co-managed the Fund since its inception in 2002. Education: B.A., University of Chicago; M.B.A., Harvard Business School.

Joel P. Fried, Chairman of PRIMECAP. He has worked in investment management since 1985, has been with PRIMECAP since 1986, has managed assets since 1987, and has co-managed the Fund since its inception in 2002. Education: B.S., University of California, Los Angeles; M.B.A., Anderson Graduate School of Business, University of California, Los Angeles.

Alfred W. Mordecai, President of PRIMECAP. He has worked in investment management and has been with PRIMECAP since 1997, has managed assets since 1999, and has co-managed the Fund since its inception in 2002. Education: B.S.E., Duke University; M.E.A., Virginia Polytechnic Institute and State University; M.B.A., Harvard Business School.

M. Mohsin Ansari, Vice Chairman of PRIMECAP. He has worked in investment management and has been with PRIMECAP since 2000, has managed assets since 2007, and has co-managed the Fund since 2007. Education: B.A., Colgate University; B.S., Washington University; M.B.A., Harvard Business School.

James M. Marchetti, Executive Vice President of PRIMECAP. He has worked in investment management and has been with PRIMECAP since 2005, has managed assets since 2014, and has co-managed the Fund since 2015. Education: B.S., Massachusetts Institute of Technology; M.B.A., MIT Sloan School of Management.

Each of these five individuals manages a portion of the Fund autonomously; there is no decision-making by committee. A small portion of the Fund’s assets is managed by individuals in PRIMECAP’s research department.

The Fund’s Statement of Additional Information provides information about each portfolio manager’s compensation, other accounts under management, and ownership of shares of the Fund.

Investing in Vanguard Funds

Purchase and Redemption of Fund Shares

Pricing of Fund Shares

Distributions and Taxes

Frequent Trading Limitations

See the prospectus for the annuity or insurance program through which Fund shares are offered for further details on transaction policies.

Do not invest with Vanguard if you are a market-timer.

Financial Highlights

Vanguard Capital Growth Portfolio

For a Share Outstanding Throughout Each Period	Year Ended December 31,
For a Share Outstanding Throughout Each Period	2025	2024	2023	2022	2021
Net Asset Value, Beginning of Period	$50.94	$46.38	$38.81	$50.69	$45.21
Investment Operations
Net Investment Income1	.541	.545	.534	.468	.356
Net Realized and Unrealized Gain (Loss) on Investments	13.304	5.612	9.693	(7.744)	8.959
Total from Investment Operations	13.845	6.157	10.227	(7.276)	9.315
Distributions
Dividends from Net Investment Income	(.560)	(.565)	(.457)	(.390)	(.480)
Distributions from Realized Capital Gains	(2.405)	(1.032)	(2.200)	(4.214)	(3.355)
Total Distributions	(2.965)	(1.597)	(2.657)	(4.604)	(3.835)
Net Asset Value, End of Period	$61.82	$50.94	$46.38	$38.81	$50.69
Total Return	28.98%	13.41%	27.98%	-15.48%	21.54%
Ratios/Supplemental Data
Net Assets, End of Period (Millions)	$2,389	$1,948	$1,786	$1,419	$1,775
Ratio of Total Expenses to Average Net Assets	0.34%	0.34%	0.34%	0.34%	0.34%
Ratio of Net Investment Income to Average Net Assets	1.02%	1.09%	1.28%	1.13%	0.73%
Portfolio Turnover Rate	15%	5%	4%	3%	5%2

1	Calculated based on average shares outstanding.
2	Excludes the value of portfolio securities received or delivered as a result of in-kind purchases or redemptions of the portfolio’s capital shares.

Additional Information

Securities Market Indexes
Listed below are the broad-based securities market index and one or more additional indexes with similar investment characteristics as the Fund, as referenced in the Fund’s Average Annual Total Returns table:

Dow Jones U.S. Total Stock Market Float Adjusted Index. An index designed to measure all U.S. equity issues with readily available prices.

Standard & Poor’s 500 Index. An index that is a widely recognized benchmark of U.S. stock market performance that is dominated by the stocks of large U.S. companies.

The “S&P 500 Index” (the “Index”) is a product of S&P Dow Jones Indices LLC, a division of S&P Global, or its affiliates (“SPDJI”), and has been licensed for use by Vanguard. Standard & Poor’s®, and S&P® are registered trademarks of Standard & Poor’s Financial Services LLC, a division of S&P Global (“S&P”) and Dow Jones® is a registered trademark of Dow Jones Trademark Holdings LLC (“Dow Jones”). The trademarks have been licensed to SPDJI and have been sublicensed for use for certain purposes by Vanguard. Vanguard Variable Insurance Funds Capital Growth Portfolio is not sponsored, endorsed, sold or promoted by SPDJI, Dow Jones, S&P, or any of their respective affiliates (collectively, “S&P Dow Jones Indices”). S&P Dow Jones Indices make no representation or warranty, express or implied, to the owners of Vanguard Variable Insurance Funds Capital Growth Portfolio or any member of the public regarding the advisability of investing in securities generally or in Vanguard Variable Insurance Funds Capital Growth Portfolio particularly or the ability of the “S&P 500 Index” (the “Index”) to track general market performance. S&P Dow Jones Indices’ only relationship to Vanguard with respect to the “S&P 500 Index” (the “Index”) is the licensing of the Index and certain trademarks, service marks and/or trade names of S&P Dow Jones Indices and/or its licensors. The “S&P 500 Index” (the “Index”) is determined, composed and calculated by S&P Dow Jones Indices without regard to Vanguard or Vanguard Variable Insurance Funds Capital Growth Portfolio. S&P Dow Jones Indices have no obligation to take the needs of Vanguard or the owners of Vanguard Variable Insurance Funds Capital Growth Portfolio into consideration in determining, composing or calculating the “S&P 500 Index” (the “Index”). S&P Dow Jones Indices are not responsible for and have not participated in the determination of the prices, and amount of Vanguard Variable Insurance Funds Capital Growth Portfolio or the timing of the issuance or sale of Vanguard Variable Insurance Funds Capital Growth Portfolio or in the determination or calculation of the equation by which Vanguard Variable Insurance Funds Capital Growth Portfolio is to be converted into cash, surrendered or redeemed, as the case may be. S&P Dow Jones Indices have no obligation or liability in connection with the administration, marketing or trading of Vanguard Variable Insurance Funds Capital Growth Portfolio. There is no assurance that investment products based on the “S&P 500 Index” (the “Index”) will accurately track index performance or provide positive investment returns. S&P Dow Jones Indices LLC is not an investment advisor. Inclusion of a security within an index is not a recommendation by S&P Dow Jones Indices to buy, sell, or hold such security, nor is it considered to be investment advice.

S&P DOW JONES INDICES DOES NOT GUARANTEE THE ADEQUACY, ACCURACY, TIMELINESS AND/OR THE COMPLETENESS OF THE INDEX OR ANY DATA RELATED THERETO OR ANY COMMUNICATION, INCLUDING BUT NOT LIMITED TO, ORAL OR WRITTEN COMMUNICATION (INCLUDING ELECTRONIC COMMUNICATIONS) WITH RESPECT THERETO. S&P DOW JONES INDICES SHALL NOT BE SUBJECT TO ANY DAMAGES OR LIABILITY FOR ANY ERRORS, OMISSIONS, OR DELAYS THEREIN. S&P

DOW JONES INDICES MAKE NO EXPRESS OR IMPLIED WARRANTIES, AND EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE OR AS TO RESULTS TO BE OBTAINED BY VANGUARD, OWNERS OF VANGUARD VARIABLE INSURANCE FUNDS CAPITAL GROWTH PORTFOLIO, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE INDEX OR WITH RESPECT TO ANY DATA RELATED THERETO. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT WHATSOEVER SHALL S&P DOW JONES INDICES BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES INCLUDING BUT NOT LIMITED TO, LOSS OF PROFITS, TRADING LOSSES, LOST TIME OR GOODWILL, EVEN IF THEY HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, WHETHER IN CONTRACT, TORT, STRICT LIABILITY, OR OTHERWISE. THERE ARE NO THIRD PARTY BENEFICIARIES OF ANY AGREEMENTS OR ARRANGEMENTS BETWEEN S&P DOW JONES INDICES AND VANGUARD, OTHER THAN THE LICENSORS OF S&P DOW JONES INDICES.

Connect with Vanguard® ˃ vanguard.com

For More Information

If you would like more information about Vanguard Variable Insurance Funds Capital Growth Portfolio, the following documents are available free upon request:

Annual/Semiannual Reports to Shareholders and Form N-CSR

Statement of Additional Information (SAI)

The SAI provides more detailed information about the Fund and is incorporated by reference into (and thus legally a part of) this Prospectus.

Telephone: 800-522-5555; Text telephone for people with hearing impairment: 800-749-7273

Information Provided by the SEC

Fund’s Investment Company Act file number: 811-05962

Vanguard Marketing Corporation, Distributor.

P 277 042026

April 28, 2026

Prospectus

Vanguard Variable Insurance Funds

Conservative Allocation Portfolio
Moderate Allocation Portfolio

This Prospectus contains financial data for the Funds through the fiscal year ended December 31, 2025.

The Securities and Exchange Commission (SEC) has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

Contents

Fund Summaries
Conservative Allocation Portfolio	1
Moderate Allocation Portfolio	9
More on the Funds	17
Investment Objectives and More on Principal Investment Strategies	18
More on Fund Risks	24
Other Investment Policies	33
Portfolio Holdings	34
Management and Distribution of the Funds	34
Investing in Vanguard Funds	37
Purchase and Redemption of Fund Shares	37
Pricing of Fund Shares	39
Distributions and Taxes	40
Frequent Trading Limitations	41
Financial Highlights	43
Additional Information	46

Conservative Allocation Portfolio

Investment Objective

Vanguard Variable Insurance Funds Conservative Allocation Portfolio (the “Fund”) seeks to provide current income and low to moderate capital appreciation.

Fees and Expenses

Annual Fund Operating Expenses
(Expenses that you pay each year as a percentage of the value of your investment)


Management Fees	0.00 %
12b-1 Distribution Fee	None
Other Expenses	0.00 %
Acquired Fund Fees and Expenses	0.12 %
Total Annual Fund Operating Expenses	0.12 %

Example

1 Year	3 Years	5 Years	10 Years
$12	$39	$68	$154

Portfolio Turnover

Principal Investment Strategies

The Fund invests in a mix of Vanguard mutual funds and other portfolios of Vanguard Variable Insurance Funds (collectively, the “Underlying Funds”) according to an asset allocation strategy that reflects an allocation of approximately 60% of the Fund’s assets to fixed income securities and 40% to common stocks. The targeted percentage of the Fund’s assets allocated to the underlying asset classes is:

• U.S. fixed income securities - 42%
• Large-cap U.S. stocks - 21%
• Foreign fixed income securities - 18%
• Foreign stocks - 16%
• Small- and mid-cap U.S. stocks - 3%

The Fund’s indirect fixed income holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by the advisor, typically with foreign currency exchange forward contracts, to minimize foreign currency exposure). The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks.

The Fund uses its investment in large-cap U.S. stocks and small- and mid-cap U.S. stocks to gain exposure to the overall domestic stock market. Although the percentage of the Fund’s assets invested in either of these two asset classes may deviate slightly from the target allocation, the combination of the two asset classes will equal approximately 24% of the Fund’s assets in the aggregate.

The board of trustees of Vanguard Variable Insurance Funds may change the targeted allocation to the underlying asset classes without shareholder approval.

Principal Risks

• General Market Risk. The markets in which the Fund and the Underlying Funds invest can be affected by a variety of factors. These factors, which can be real or perceived, may include economic, market, political, and regulatory conditions and developments as well as local, regional, or global events such as wars, military conflicts, natural disasters, and public health issues. In addition, investor sentiment and expectations regarding these factors can also impact the markets. Different parts of the market, including different industries and sectors as well as different types of securities, may react differently to factors that affect the market. These factors can contribute to market uncertainty, market volatility, and fluctuations in the value of the Fund’s investments, thereby resulting in potential losses to the Fund over short or long periods.

• Investing in Bond Markets. Certain Underlying Funds invest in bonds. As a result, these Underlying Funds may be impacted by the general condition of the bond markets and by factors that affect bonds and bond issuers. For example, as a general rule, bond prices and interest rates move in opposite directions. When interest rates rise, bond prices tend to fall, and when interest rates fall, bond prices tend to go up. Bond income also is affected by changes in interest rates. Interest rates can rise or fall for a number of reasons, including, but not limited to, central bank monetary policy, inflationary or deflationary pressures, and changes in general market and economic conditions. Changing interest rates, including, but not limited to, rates that fall below zero, could have unpredictable effects on the overall market and may expose the bond markets in particular to heightened volatility and potential illiquidity. The degree to which an Underlying Fund is impacted by certain bond market risks may vary based on factors disclosed in its principal investment strategies, such as the types of bonds in which it invests and the overall credit quality, average maturity, and/or average duration of its bond holdings.

• Interest Rate Risk. During periods of rising interest rates, bond prices overall may decline, which could result in a decline in an Underlying Fund’s value. The prices of longer-term bonds are more sensitive to changes in interest rates than the prices of shorter-term bonds.

• Income Risk. During periods of falling interest rates, the Fund’s and/or an Underlying Fund’s income may decline. The income paid by shorter-term bonds is subject to a higher degree of fluctuation than the income paid by longer-term bonds.

• Credit Risk. Credit risk refers to the chance that an issuer will default (fail to meet its credit obligations) or fail to make payments in a timely manner, which

could result in a loss to an Underlying Fund. In addition, negative perceptions of an issuer’s ability to make payments can cause the price of a security to decline. While all debt securities are subject to credit risk to some extent, those with higher credit quality ratings generally pose less credit risk than those with lower credit quality ratings.

• Bond Liquidity Risk. If an Underlying Fund is unable to sell a security at an advantageous time or price, its returns may be reduced. There may be limited trading in the secondary market for certain debt securities, which could make them more difficult to value or sell.

• Call Risk. Certain bonds held by an Underlying Fund may be callable. The issuer of a callable bond has the right to “call” (redeem) the bond before its maturity date. Calls on bonds held by an Underlying Fund would result in the Underlying Fund losing any price appreciation above the bond’s call price. In addition, because bond calls occur more frequently during periods of falling interest rates, the Underlying Fund likely would be forced to reinvest the proceeds of any called bonds at a lower interest rate than that of the called bonds, resulting in a decline in the Underlying Fund’s income and a potential loss in the value of the Underlying Fund’s investments. Frequent bond calls and subsequent reinvestments of the proceeds also would increase an Underlying Fund’s turnover rate.

• Prepayment Risk. Certain bonds held by the Underlying Funds are subject to risks associated with prepayment. Prepayment risk for callable bonds is described under Call Risk. With respect to mortgage-backed, asset-backed, and similar debt securities, prepayment typically refers to borrowers repaying their debt early (e.g., before the maturity date). Prepayment of bonds held by an Underlying Fund would result in the Underlying Fund losing any price appreciation above the amount repaid (or the bond’s call price, in the case of callable bonds). In addition, because prepayments occur more frequently in low interest rate environments, the Underlying Fund likely would be forced to reinvest the proceeds from any prepayments at a lower interest rate than when the prepaid bonds were purchased, resulting in a decline in the Underlying Fund’s income and a potential loss in the value of the Underlying Fund’s investments. Frequent prepayments and subsequent reinvestment of the proceeds also would increase the Underlying Fund’s turnover rate.

• Extension Risk. During periods of rising interest rates, certain bonds held by an Underlying Fund may be paid off substantially more slowly than originally anticipated. As a result, the value of the bonds may fall, resulting in a decline in an Underlying Fund’s income and a potential loss in the value of an Underlying Fund’s investments.

• Investing in Equity Markets. Certain Underlying Funds invest in the equity markets. Equity markets have historically been cyclical, having periods of time when stock values rise and fall. Market volatility can lead to significant fluctuations in stock values, resulting in potential losses to these Underlying Funds.

• Investing in Foreign Markets. Foreign markets can perform differently than U.S. markets. World events could adversely affect the value and/or liquidity of securities of foreign companies or foreign issuers, potentially in ways that differ from impacts to U.S. companies or issuers. Further, global economies and financial markets are becoming increasingly interconnected, which increases the possibility that conditions in one country or region could adversely impact a different country or region. In addition, the rights and remedies associated with investments in a fund that invests in foreign securities may be different than a fund that invests in domestic securities. To the extent that the Underlying Fund invests a large portion of their assets in securities of companies located primarily in one country or region, the Fund’s performance may be hurt disproportionately by the poor performance of the Underlying Funds’ investments in such country or region.

• Currency Risk. Certain Underlying Funds are subject to the risk that foreign currency will perform differently than U.S. dollars and increase the potential loss to an Underlying Fund. Currency exchange rates may be volatile, move rapidly, and change as a result of changes in interest rates, inflation rates, government surpluses or deficits, and monetary policy or currency controls imposed by local governments or supranational entities such as the International Monetary Fund. Changes in currency exchange rates can affect the value of an Underlying Fund’s holdings.

• Currency Hedging. Certain Underlying Funds may attempt to offset currency risk through a hedging strategy; however, by doing so, these Underlying Funds may not be able to capture gains that they could otherwise realize if they did not have a hedging strategy. It generally is not possible to perfectly hedge the risk posed by foreign currency exposure. Hedging transactions can increase transaction costs and subject an Underlying Fund to the risk that a counterparty is unable to fulfill its contractual obligation, in which case the Underlying Fund could be subject to additional loss.

• Underlying Funds Risk. The Fund invests substantially all of its assets in Underlying Funds. This means that the Fund is exposed to all of the risks associated with the investment strategies and policies of those Underlying Funds, including the risk that the Underlying Funds will not meet their investment objectives.

• Allocation to Underlying Funds. The advisor’s selection of Underlying Funds, and the allocation of a high percentage of the Fund’s assets to a relatively few number of Underlying Funds, may cause the Fund to be hurt disproportionately by the poor performance of any one Underlying Fund or to underperform other funds with a similar investment objective.

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

Annual Total Returns

The following bar chart and table show the Fund’s historical performance and are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of a broad-based securities market index and one or more additional indexes with similar investment characteristics as the Fund. The Conservative Allocation Composite Index is weighted 42% Bloomberg U.S. Aggregate Float Adjusted Index, 24% S&P Total Market Index, 18% Bloomberg Global Aggregate ex-USD Float Adjusted RIC Capped Index (USD Hedged), and 16% FTSE Global All Cap ex US Index as of April 28, 2017. Previously, the composite was weighted 48% Bloomberg U.S. Aggregate Float Adjusted Index, 28% S&P Total Market Index, 12% Bloomberg Global Aggregate ex-USD Float Adjusted RIC Capped Index (USD Hedged), and 12% FTSE Global All Cap ex US Index through April 27, 2017. International stock benchmark returns are adjusted for withholding taxes. The Fund’s returns are net of its expenses, but do not reflect additional fees and expenses that are deducted by the annuity or life insurance program through which you invest. If such fees and expenses were included in the calculation of the Fund’s returns, the returns would be lower. Keep in mind that the Fund’s past performance does not indicate how the Fund will perform in the future. Updated performance information is available on our website for Financial Advisors at advisors.vanguard.com.

Annual Total Returns — Conservative Allocation Portfolio

During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were:

	Total Return	Quarter
Highest	9.74 %	June 30, 2020
Lowest	-9.15 %	June 30, 2022

Average Annual Total Returns for Periods Ended December 31, 2025

	1 Year	5 Years	10 Years
Conservative Allocation Portfolio	12.73 %	4.22 %	6.14 %
Conservative Allocation Composite Index (reflects no deduction for fees, expenses, or taxes)	12.90 %	4.48 %	6.38 %
Bloomberg U.S. Aggregate Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	7.21	-0.37	2.05
Dow Jones U.S. Total Stock Market Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	17.05	13.07	14.21

Investment Advisor

The Vanguard Group, Inc. (Vanguard) through its wholly owned subsidiary, Vanguard Capital Management (VCM). VCM exercises portfolio management responsibilities for the Fund.

Portfolio Managers

Roger A. Aliaga-Diaz, Ph.D., Portfolio Manager at VCM. He has co-managed the Fund since 2023.

Aurélie Denis, CFA, Portfolio Manager at VCM. She has co-managed the Fund since 2023.

Michael R. Roach, CFA, Portfolio Manager at VCM. He has co-managed the Fund since 2023.

Walter Nejman, Portfolio Manager at VCM. He has co-managed the Fund since 2013.

Purchase and Sale of Fund Shares

Tax Information

Payments to Financial Intermediaries

The Fund and its advisor do not pay financial intermediaries for sales of Fund shares.

Moderate Allocation Portfolio

Investment Objective

Vanguard Variable Insurance Funds Moderate Allocation Portfolio (the “Fund”) seeks to provide current income and low to moderate capital appreciation.

Fees and Expenses

Annual Fund Operating Expenses
(Expenses that you pay each year as a percentage of the value of your investment)


Management Fees	0.00 %
12b-1 Distribution Fee	None
Other Expenses	0.00 %
Acquired Fund Fees and Expenses	0.12 %
Total Annual Fund Operating Expenses	0.12 %

Example

1 Year	3 Years	5 Years	10 Years
$12	$39	$68	$154

Portfolio Turnover

Principal Investment Strategies

The Fund invests in a mix of Vanguard mutual funds and other portfolios of Vanguard Variable Insurance Funds (collectively, the “Underlying Funds”) according to an asset allocation strategy that reflects an allocation of approximately 60% of the Fund’s assets to common stocks and 40% to fixed income securities. The targeted percentage of the Fund’s assets allocated to the underlying asset classes is:

• Large-cap U.S. stocks - 32%
• U.S. fixed income securities - 28%
• Foreign stocks - 24%
• Foreign fixed income securities - 12%
• Small- and mid-cap U.S. stocks - 4%

The Fund’s indirect stock holdings are a diversified mix of U.S. and foreign large-, mid-, and small-capitalization stocks. The Fund’s indirect fixed income holdings are a diversified mix of short-, intermediate-, and long-term U.S. government, U.S. agency, and investment-grade U.S. corporate bonds; mortgage-backed and asset-backed securities; and government, agency, corporate, and investment-grade foreign bonds issued in currencies other than the U.S. dollar (but hedged by the advisor, typically with foreign currency exchange forward contracts, to minimize foreign currency exposure).

The board of trustees of Vanguard Variable Insurance Funds may change the targeted allocation to the underlying asset classes without shareholder approval.

Principal Risks

illiquidity. The degree to which an Underlying Fund is impacted by certain bond market risks may vary based on factors disclosed in its principal investment strategies, such as the types of bonds in which it invests and the overall credit quality, average maturity, and/or average duration of its bond holdings.

• Credit Risk. Credit risk refers to the chance that an issuer will default (fail to meet its credit obligations) or fail to make payments in a timely manner, which could result in a loss to an Underlying Fund. In addition, negative perceptions of an issuer’s ability to make payments can cause the price of a security to decline. While all debt securities are subject to credit risk to some extent, those with higher credit quality ratings generally pose less credit risk than those with lower credit quality ratings.

low interest rate environments, the Underlying Fund likely would be forced to reinvest the proceeds from any prepayments at a lower interest rate than when the prepaid bonds were purchased, resulting in a decline in the Underlying Fund’s income and a potential loss in the value of the Underlying Fund’s investments. Frequent prepayments and subsequent reinvestment of the proceeds also would increase the Underlying Fund’s turnover rate.

Funds, including the risk that the Underlying Funds will not meet their investment objectives.

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

Annual Total Returns

The following bar chart and table show the Fund’s historical performance and are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of a broad-based securities market index and one or more additional indexes with similar investment characteristics as the Fund. The Moderate Allocation Composite Index is weighted 36% S&P Total Market Index, 28% Bloomberg U.S. Aggregate Float Adjusted Index, 24% FTSE Global All Cap ex US Index, and 12% Bloomberg Global Aggregate ex USD Float Adjusted RIC Capped Index (USD Hedged) as of April 28, 2017. Previously, the composite was weighted 42% S&P Total Market Index, 32% Bloomberg U.S. Aggregate Float Adjusted Index, 18% FTSE Global All Cap ex US Index, and 8% Bloomberg Global Aggregate ex-USD Float Adjusted RIC Capped Index (USD Hedged) through April 27, 2017. International stock benchmark returns are adjusted for withholding taxes. The Fund’s returns are net of its expenses, but do not reflect additional fees and expenses that are deducted by the annuity or life insurance program through which you invest. If such fees and expenses were included in the calculation of the Fund’s returns, the returns would be lower. Keep in mind that the Fund’s past performance does not indicate how the Fund will perform in the future. Updated performance information is available on our website for Financial Advisors at advisors.vanguard.com.

Annual Total Returns — Moderate Allocation Portfolio

During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were:

	Total Return	Quarter
Highest	13.26 %	June 30, 2020
Lowest	-12.77 %	March 31, 2020

Average Annual Total Returns for Periods Ended December 31, 2025

	1 Year	5 Years	10 Years
Moderate Allocation Portfolio	16.19 %	6.51 %	8.14 %
Moderate Allocation Composite Index (reflects no deduction for fees, expenses, or taxes)	16.41 %	6.83 %	8.43 %
Dow Jones U.S. Total Stock Market Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	17.05	13.07	14.21
Bloomberg U.S. Aggregate Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	7.21	-0.37	2.05

Investment Advisor

The Vanguard Group, Inc. (Vanguard) through its wholly owned subsidiary, Vanguard Capital Management (VCM). VCM exercises portfolio management responsibilities for the Fund.

Portfolio Managers

Roger A. Aliaga-Diaz, Ph.D., Portfolio Manager at VCM. He has co-managed the Fund since 2023.

Aurélie Denis, CFA, Portfolio Manager at VCM. She has co-managed the Fund since 2023.

Michael R. Roach, CFA, Portfolio Manager at VCM. He has co-managed the Fund since 2023.

Walter Nejman, Portfolio Manager at VCM. He has co-managed the Fund since 2013.

Purchase and Sale of Fund Shares

Tax Information

Payments to Financial Intermediaries

The Fund and its advisor do not pay financial intermediaries for sales of Fund shares.

More on the Funds

This Prospectus provides information about the following Vanguard funds (each, a “Fund” and collectively, the “Funds”):

• Vanguard Variable Insurance Funds Conservative Allocation Portfolio

• Vanguard Variable Insurance Funds Moderate Allocation Portfolio

Each Fund is a series of Vanguard Variable Insurance Funds (the “Trust”). Reading this prospectus will help you decide whether a Fund is the right investment for you. Each Fund is a mutual fund used solely as an investment option for annuity or life insurance contracts offered by insurance companies. This means that you cannot purchase shares of a Fund directly, but only through an annuity or life insurance contract offered by an insurance company. Each Fund is separate from other Vanguard mutual funds, even when a Fund and a Vanguard mutual fund have the same investment objective and advisor. Each Fund’s investment performance will differ from the performance of other Vanguard funds because of differences in the securities held and because of administrative and insurance costs associated with the annuity or life insurance program through which you invest.

As you consider an investment in a Fund, you should take into account your tolerance for fluctuations in the securities markets. The costs of investing are another important consideration. As an owner of the annuity or life insurance contract through which you invest in a Fund, you will pay a proportionate share of the fees and expenses associated with a Fund’s investments in the Underlying Funds, including the costs of operating the Underlying Funds and any transaction costs incurred when the Underlying Funds buy or sell securities. These costs can erode a substantial portion of the gross income or the capital appreciation the Underlying Funds achieve. Even seemingly small differences can, over time, have a dramatic effect on the Underlying Funds’ performance, which in turn can impact a Fund’s performance.

Investment Objectives and More on Principal Investment Strategies

In this section, you will find more information about each Fund’s investment objective and the principal investment strategies and policies that each Fund uses in pursuit of its investment objective. The Trust’s board of trustees (the “Board”) oversees each Fund’s management. The Board may approve changes to a Fund’s strategies or policies in the interest of shareholders without shareholder approval unless the strategy or policy is designated as fundamental.

Investment Objectives

The Funds’ investment objectives are as follows:

• Vanguard Variable Insurance Funds Conservative Allocation Portfolio seeks to provide current income and low to moderate capital appreciation.
• Variable Insurance Funds Moderate Allocation Portfolio seeks to provide current income and low to moderate capital appreciation.

Each Fund’s investment objective is fundamental and may not be materially changed without shareholder approval.

Implementation of Investment Objectives

Each Fund is a balanced fund. Balanced funds generally seek to provide some combination of current income and capital appreciation by investing in a mix of stocks and bonds. Because prices of stocks and bonds can respond differently to economic events and influences, a balanced fund should experience less volatility than a fund investing exclusively in stocks. Each Fund is a fund of funds that seeks to achieve its investment objective primarily by investing in Underlying Funds rather than in individual securities.

What is Asset Allocation?

Asset allocation – that is, dividing your investment among bonds, stocks,

and short-term investments – is one of the most critical decisions you can

make as an investor. The best asset mix for you will depend on your

personal investment objective, time horizon, and risk tolerance. Some

balanced funds maintain set asset allocations, while other balanced funds

have asset allocations that change over time.

The Funds offer two preset asset allocation strategies. The asset allocation for each Vanguard Allocation Portfolio reflects its greater or lesser emphasis on pursuing current income or capital growth, providing investors with a simple way to meet typical investment needs at different stages of life. The following table illustrates the targeted asset allocation range for each Fund:

Vanguard Fund	Stocks	Fixed Income Securities
Vanguard Variable Insurance Funds Conservative Allocation Portfolio	40%	60%
Vanguard Variable Insurance Funds Moderate Allocation Portfolio	60%	40%

The Board allocates each Fund’s assets among the equity and fixed income asset classes and Underlying Funds based on the Fund’s investment objective and policies. The Board may change these asset allocations and the mix of Underlying Funds from time to time without shareholder approval. The Board may also add or remove underlying funds without shareholder approval.

Security Selection

Each Fund invests in a mix of Underlying Funds that hold U.S. and foreign stocks and fixed income securities in order to pursue a target allocation of stocks and bonds. The following table shows the targeted percentages for each Fund’s assets allocated to the underlying asset classes:

	Underlying Asset Class
Vanguard Allocation Portfolios	U.S. Fixed Income Securities	Large-Cap U.S. Stocks	Foreign Fixed Income Securities	Foreign Stocks	Small- and Mid-Cap U.S. Stocks	Totals1
Conservative Allocation Portfolio	42%	21%	18%	16%	3%	100%
Moderate Allocation Portfolio	28%	32%	12%	24%	4%	100%

1 Due to rounding, the total percentage may not be equal to 100%.

Underlying Funds. The following paragraphs briefly describe the Underlying Funds in which the Funds currently intend to invest. More information regarding each Underlying Fund can be found in its prospectus.

• Vanguard Variable Insurance Funds Equity Index Portfolio seeks to track the performance of the S&P 500 Index, a float-adjusted market cap-weighted index which includes 500 of the top companies in leading industries of the U.S. economy and covers approximately 80% of available market capitalization.

• Vanguard Extended Market Index Fund seeks to track the performance of the S&P Completion Index, a float-adjusted market cap weighted index consisting of the stocks of small and mid-size U.S. companies.

• Vanguard Total International Stock Index Fund seeks to track the performance of the FTSE Global All Cap ex US Index, a float-adjusted

market-capitalization weighted index designed to measure equity market performance of companies located in developed and emerging markets, excluding the United States.

• Vanguard Variable Insurance Funds Total Bond Market Index Portfolio seeks to track the performance of the Bloomberg U.S. Aggregate Float Adjusted Index which measures the performance of a wide spectrum of public, investment-grade, taxable bonds in the United States—including government, corporate, and international dollar-denominated bonds, as well as mortgage-backed and asset-backed securities—all with maturities of more than 1 year.

• Vanguard Total International Bond Index Fund seeks to track the performance of the Bloomberg Global Aggregate ex-USD Float Adjusted RIC Capped Index (USD Hedged), a market-value-weighted index that provides a broad-based measure of the global, investment-grade, fixed-rate bond markets. This index includes government, government agency, corporate, and securitized investment-grade bonds of issuers located in developed and emerging markets, all issued in currencies other than the U.S. dollar and with maturities of more than one year. The Underlying Index is capped to comply with investment company diversification standards of the Internal Revenue Code, but is not designed to satisfy the diversification requirements of the Investment Company Act of 1940. To correlate to the returns of this index (which is U.S.-dollar hedged) and to minimize the currency risk associated with foreign currency bonds, this Underlying Fund seeks to hedge its foreign currency exposure.

The Funds’ investments in the Underlying Funds may be affected by a variety of factors. For example, an Underlying Fund may stop accepting or may limit additional investments, forcing the Funds to invest in a different Underlying Fund.

Underlying Fund Investments. By owning shares of Underlying Funds, each Fund invests indirectly, to varying degrees, in U.S. stocks, with an emphasis on large-cap stocks. To a lesser extent, each Fund also invests in foreign stocks. Through their investments in one underlying fund (Vanguard Variable Insurance Funds Equity Index Portfolio), each Fund holds a representative sample of the stocks that make up the S&P 500 Index, which is dominated by large-cap stocks. Through another underlying fund (Vanguard Extended Market Index Fund), each Fund holds a representative sample of the stocks that make up the S&P Completion Index, which represents mid- and small-capitalization stocks.

Stocks of publicly traded companies are often classified according to market capitalization, which is the market value of a company’s outstanding shares. These classifications typically include small-cap, mid-cap, and large-cap. It is important to understand that there are no “official” definitions of small-, mid-, and large cap and that market capitalization ranges can change over time.

A fund’s median market capitalization, which is the midpoint of the market capitalization of the fund’s stocks weighted by the proportion of the fund’s assets invested in each stock, can be used as an indicator of the size of the companies in which it invests. Stocks representing half of a fund’s assets will have market capitalizations above the median, and the rest will fall below it. As of the calendar year ended December 31, 2025, the weighted average of the asset-weighted median market capitalizations of the underlying U.S. equity funds’ stock holdings for Vanguard Variable Insurance Funds Conservative Allocation Portfolio was approximately $126 billion, and approximately $126 billion for Vanguard Variable Insurance Funds Moderate Allocation Portfolio.

Because each Fund invests in Vanguard Variable Insurance Funds Equity Index Portfolio and Vanguard Extended Market Index Fund so as to gain exposure to the overall U.S. stock market, each Fund may shift its holdings between these two underlying funds to remain proportionate with the overall U.S. stock market.

Each Fund also invests in Vanguard Total International Stock Index Fund. As of the calendar year ended December 31, 2025, the underlying foreign equity fund’s stock holdings had an asset-weighted median market capitalization of approximately $48 million.

By owning shares of Underlying Funds, each Fund also indirectly invests, to varying degrees, in government and corporate bonds, as well as in mortgage-backed and asset-backed securities.

By owning shares of Vanguard Variable Insurance Funds Total Bond Market Index Portfolio, each Fund indirectly invests, to varying degrees, in U.S. government and U.S. corporate bonds, as well as in mortgage-backed and asset-backed securities. By owning shares of Vanguard Total International Bond Index Fund, each Fund indirectly invests in currency-hedged foreign bonds.

As of the calendar year ended December 31, 2025, the bonds in the domestic fixed income Underlying Fund maintained a dollar-weighted average maturity ranging from less than a year to 97 years. The bonds in the international fixed income Underlying Fund also maintained a dollar-weighted average maturity ranging from less than a year to 96 years.

Additional Information Regarding the Underlying Funds’ Investments

The Underlying Funds’ stock investments are described in more detail below.

• Small-Cap Stocks represent smaller companies, which may be newer or operate in niche markets. These companies can offer higher growth potential than larger companies and may be more agile in adapting to market changes. However, they also face greater risks, such as limited access to capital and vulnerability during economic downturns.

The Underlying Funds’ bond investments are described in more detail below.