485BPOS

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A
REGISTRATION STATEMENT
(NO. 33-06001)

UNDER THE SECURITIES ACT OF 1933

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Pre-Effective Amendment No.

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Post-Effective Amendment No. 115

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and

REGISTRATION STATEMENT
(NO. 811-04681)

UNDER THE INVESTMENT COMPANY ACT OF 1940

Amendment No. 117

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Vanguard Bond Index 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 Bond Index Funds

Investor Shares

Vanguard Total Bond Market Index Fund Investor Shares (VBMFX)
Vanguard Short-Term Bond Index Fund Investor Shares (VBISX)
Vanguard Intermediate-Term Bond Index Fund Investor Shares (VBIIX)

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
Vanguard Total Bond Market Index Fund	1
Vanguard Short-Term Bond Index Fund	7
Vanguard Intermediate-Term Bond Index Fund	13
More on the Funds	19
Investment Objectives and More on Principal Investment Strategies	19
More on Fund Risks	25
Other Investment Policies	30
Portfolio Holdings	32
Management and Distribution of the Funds	32
Investing in Vanguard Funds	35
Share Classes and Converting Shares	36
Pricing of Fund Shares	38
Purchase, Redemption, and Exchange of Fund Shares	40
Reservation of Rights	50
Dividends, Distributions, and Taxes	51
Frequent Trading Limitations	54
Financial Highlights	57
Additional Information	60
Contacting Vanguard	63

Vanguard Total Bond Market Index Fund

Investment Objective

Vanguard Total Bond Market Index Fund (the “Fund”) seeks to track the performance of a broad, market-weighted bond index.

Fees and Expenses

The following tables describe the fees and expenses you may pay if you buy, hold, and sell Investor Shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and example below.

Shareholder Fees
(Fees paid directly from your investment)


Sales Charge (Load) Imposed on Purchases	None
Purchase Fee	None
Sales Charge (Load) Imposed on Reinvested Dividends	None
Redemption Fee	None
Account Service Fee Per Year (for certain fund account balances below $5,000,000)	$25

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


Management Fees	0.14 %
12b-1 Distribution Fee	None
Other Expenses	0.01 %
Total Annual Fund Operating Expenses	0.15 %

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
$15	$48	$85	$192

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 and may result in higher taxes when Fund shares are held in a taxable account. 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 38% of the average value of its portfolio.

Principal Investment Strategies

The Fund employs an indexing investment approach designed to track the performance of the Bloomberg U.S. Aggregate Float Adjusted Index (the “Target Index”). The Target Index 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. Under normal circumstances, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in the bonds that make up the Target Index and in securities that the advisor determines have substantially identical economic characteristics to the securities that make up the Target Index.

The Fund invests by sampling the Target Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Target Index in terms of key risk factors and other characteristics. The Fund maintains a dollar-weighted average maturity consistent with that of the Target Index. As of December 31, 2025, the dollar-weighted average maturity of the Target Index was 8.19 years.

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 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.

• Bond Liquidity Risk. If the 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 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.

• Index Investing. The Fund is subject to risks associated with index investing. Because the Fund generally seeks to track the performance of the Target Index regardless of how the Target Index is performing, the Fund’s performance may be lower than it would be if it were actively managed. Additionally, because the Fund does not hold all of the securities included in the Target Index, it is subject to the risk that the representative sample of securities selected by the advisor will, in the aggregate, vary from the investment profile of the full Target Index. The performance of the Fund’s investments, in the aggregate, may not match the investment performance of the Target Index. This risk, known as tracking error risk, may be heightened during times of increased market volatility or under other unusual market conditions. The Fund also could be negatively impacted by changes to the Target Index made by the index provider or by errors made by the index provider. Any gains, losses, or costs associated with or resulting from an error made by the index provider will generally be borne by the Fund and, as a result, the Fund’s shareholders.

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’s Investor Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Investor Shares compare with those of a broad-based securities market index. Keep in mind that the Fund’s past

performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance.

Annual Total Returns — Vanguard Total Bond Market Index Fund Investor Shares

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

	Total Return	Quarter
Highest	6.66 %	December 31, 2023
Lowest	-6.01 %	March 31, 2022

Average Annual Total Returns for Periods Ended December 31, 2025

	1 Year	5 Years	10 Years
Vanguard Total Bond Market Index Fund Investor Shares
Return Before Taxes	7.03 %	-0.52 %	1.89 %
Return After Taxes on Distributions	5.40	-1.70	0.76
Return After Taxes on Distributions and Sale of Fund Shares	4.14	-0.90	0.96
Bloomberg U.S. Aggregate Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	7.21 %	-0.37 %	2.05 %

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. After-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

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 Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and Portfolio Manager at VCM. He has managed the Fund since 2013.

Purchase and Sale of Fund Shares

The Fund’s Investor Shares are generally available only to Vanguard funds that operate as funds of funds and to certain retirement plan clients that receive recordkeeping services from Vanguard.

Tax Information

The Fund’s distributions may be taxable as ordinary income or capital gains. If you are investing through a tax-advantaged account, such as an IRA or an employer-sponsored retirement or savings plan, special tax rules apply. 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.

Vanguard Short-Term Bond Index Fund

Investment Objective

Vanguard Short-Term Bond Index Fund (the “Fund”) seeks to track the performance of a market-weighted bond index with a short-term dollar-weighted average maturity.

Fees and Expenses

Shareholder Fees
(Fees paid directly from your investment)


Sales Charge (Load) Imposed on Purchases	None
Purchase Fee	None
Sales Charge (Load) Imposed on Reinvested Dividends	None
Redemption Fee	None
Account Service Fee Per Year (for certain fund account balances below $5,000,000)	$25

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


Management Fees	0.14 %
12b-1 Distribution Fee	None
Other Expenses	0.01 %
Total Annual Fund Operating Expenses	0.15 %

Example

1 Year	3 Years	5 Years	10 Years
$15	$48	$85	$192

Portfolio Turnover

Principal Investment Strategies

The Fund employs an indexing investment approach designed to track the performance of the Bloomberg U.S. 1-5 Year Government/Credit Float Adjusted Index (the “Target Index”), which includes all medium and larger issues of U.S. government, investment-grade corporate, and investment-grade international dollar-denominated bonds that have maturities between 1 and 5 years and are publicly issued. Under normal circumstances, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in the bonds that make up the Target Index.

Principal Risks

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.

• Index Investing. The Fund is subject to risks associated with index investing. Because the Fund generally seeks to track the performance of the Target

Index regardless of how the Target Index is performing, the Fund’s performance may be lower than it would be if it were actively managed. Additionally, because the Fund does not hold all of the securities included in the Target Index, it is subject to the risk that the representative sample of securities selected by the advisor will, in the aggregate, vary from the investment profile of the full Target Index. The performance of the Fund’s investments, in the aggregate, may not match the investment performance of the Target Index. This risk, known as tracking error risk, may be heightened during times of increased market volatility or under other unusual market conditions. The Fund also could be negatively impacted by changes to the Target Index made by the index provider or by errors made by the index provider. Any gains, losses, or costs associated with or resulting from an error made by the index provider will generally be borne by the Fund and, as a result, the Fund’s shareholders.

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 — Vanguard Short-Term Bond Index Fund Investor Shares

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

	Total Return	Quarter
Highest	3.46 %	September 30, 2024
Lowest	-3.42 %	March 31, 2022

Average Annual Total Returns for Periods Ended December 31, 2025

	1 Year	5 Years	10 Years
Vanguard Short-Term Bond Index Fund Investor Shares
Return Before Taxes	5.98 %	1.43 %	2.02 %
Return After Taxes on Distributions	4.37	0.45	1.16
Return After Taxes on Distributions and Sale of Fund Shares	3.52	0.67	1.17
Bloomberg U.S. 1-5 Year Gov/Credit Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	6.11 %	1.56 %	2.17 %
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 Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and Portfolio Manager at VCM. He has managed the Fund since 2013.

Purchase and Sale of Fund Shares

The Fund’s Investor Shares are generally available only to Vanguard funds that operate as funds of funds and to certain retirement plan clients that receive recordkeeping services from Vanguard.

Tax Information

Payments to Financial Intermediaries

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

Vanguard Intermediate-Term Bond Index Fund

Investment Objective

Vanguard Intermediate-Term Bond Index Fund (the “Fund”) seeks to track the performance of a market-weighted bond index with an intermediate-term dollar-weighted average maturity.

Fees and Expenses

Shareholder Fees
(Fees paid directly from your investment)


Sales Charge (Load) Imposed on Purchases	None
Purchase Fee	None
Sales Charge (Load) Imposed on Reinvested Dividends	None
Redemption Fee	None
Account Service Fee Per Year (for certain fund account balances below $5,000,000)	$25

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


Management Fees	0.14 %
12b-1 Distribution Fee	None
Other Expenses	0.01 %
Total Annual Fund Operating Expenses	0.15 %

Example

1 Year	3 Years	5 Years	10 Years
$15	$48	$85	$192

Portfolio Turnover

Principal Investment Strategies

The Fund employs an indexing investment approach designed to track the performance of the Bloomberg U.S. 5-10 Year Government/Credit Float Adjusted Index (the “Target Index”), which includes all medium and larger issues of U.S. government, investment-grade corporate, and investment-grade international dollar-denominated bonds that have maturities between 5 and 10 years and are publicly issued. Under normal circumstances, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in the bonds that make up the Target Index.

Principal Risks

• Index Investing. The Fund is subject to risks associated with index investing. Because the Fund generally seeks to track the performance of the Target

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 — Vanguard Intermediate-Term Bond Index Fund Investor Shares

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

	Total Return	Quarter
Highest	6.85 %	December 31, 2023
Lowest	-6.28 %	March 31, 2022

Average Annual Total Returns for Periods Ended December 31, 2025

	1 Year	5 Years	10 Years
Vanguard Intermediate-Term Bond Index Fund Investor Shares
Return Before Taxes	8.46 %	-0.29 %	2.39 %
Return After Taxes on Distributions	6.72	-1.54	1.18
Return After Taxes on Distributions and Sale of Fund Shares	4.98	-0.73	1.33
Bloomberg U.S. 5-10 Year Gov/Credit Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	8.76 %	-0.15 %	2.55 %
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 Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and Portfolio Manager at VCM. He has managed the Fund since 2008.

Purchase and Sale of Fund Shares

The Fund’s Investor Shares are generally available only to Vanguard funds that operate as funds of funds and to certain retirement plan clients that receive recordkeeping services from Vanguard.

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 Total Bond Market Index Fund

• Vanguard Short-Term Bond Index Fund

• Vanguard Intermediate-Term Bond Index Fund

Each Fund is a series of Vanguard Bond Index Funds (the “Trust”). Reading this Prospectus will help you decide whether a Fund is the right investment for you.

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 a Fund shareholder, you will pay a proportionate share of the costs of operating a Fund and any transaction costs incurred when a Fund buys or sells securities, including costs generated by shareholders of other share classes to the extent a Fund offers more than one share class. These costs can erode a substantial portion of the gross income or the capital appreciation a Fund achieves. Even seemingly small differences can, over time, have a dramatic effect on 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 Total Bond Market Index Fund seeks to track the performance of a broad, market-weighted bond index.
• Vanguard Short-Term Bond Index Fund seeks to track the performance of a market-weighted bond index with a short-term dollar-weighted average maturity.
• Vanguard Intermediate-Term Bond Index Fund seeks to track the performance of a market-weighted bond index with an intermediate-term dollar-weighted average maturity.

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

Implementation of Investment Objectives

To achieve its investment objective, each Fund employs an indexing, or passive, investment approach designed to track the performance of its Target Index.

Vanguard Fund	Target Index
Vanguard Total Bond Market Index Fund	Bloomberg U.S. Aggregate Float Adjusted Index
Vanguard Short-Term Bond Index Fund	Bloomberg U.S. 1-5 Year Government/Credit Float Adjusted Index
Vanguard Intermediate-Term Bond Index Fund	Bloomberg U.S. 5-10 Year Government/Credit Float Adjusted Index

The Target Indexes for Vanguard Short-Term Bond Index Fund and Vanguard Intermediate-Term Bond Index Funds are subsets of the Bloomberg U.S. Aggregate Float Adjusted Index.

What are Index Funds?

Index funds attempt to track—not outperform—the performance of a

specified market index. An index is a group of securities whose overall

performance is used as a standard to measure the investment

performance of a particular market. Some indexes represent entire

markets, such as the U.S. stock market, while others cover a segment of a

market, such as short-term bonds.

One cannot invest directly in an index. Instead, an index fund’s advisor will

typically seek to hold all, or substantially all, of the securities that make up

the fund’s target index (often referred to as “replicating” an index or a “full

replication” approach) or a representative sample of the securities that

make up a fund’s target index (“sampling” an index).

Under normal circumstances, each Fund except Vanguard Total Bond Market Index Fund, invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in the bonds that make up the Target Index. Under normal circumstances, Vanguard Total Bond Market Index Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in the bonds that make up the Target Index and in securities that the advisor determines have substantially identical economic characteristics to the securities that make up the Target Index. Investments in derivatives may be counted toward the Fund’s 80% policy to the extent that

they provide investment exposure to the securities included within the policy or to one or more market risk factors associated with such securities. Each Fund may change its 80% policy only upon 60 days’ notice to shareholders.

Security Selection

Each Fund invests by sampling its Target Index. The advisor buys and sells securities for the Fund for the purpose of tracking the Target Index.

Using quantitative and qualitative methods, each Fund’s advisor generally selects a representative sample of securities that approximates the Fund’s full Target Index in terms of key risk factors and other characteristics. These factors include duration, cash flow, quality, and callability of the underlying bonds. In addition, each Fund keeps industry sector and subsector exposure within tight boundaries relative to its Target Index. The maximum overweight (or underweight) is constrained at the issuer level with the goal of producing well-diversified exposure in the portfolio.

Each Target Index is described below:

• Vanguard Total Bond Index Fund tracks the performance of the Bloomberg U.S. Aggregate Float Adjusted Index, which includes 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 Short-Term Bond Index Fund tracks the performance of the Bloomberg U.S. 1-5 Year Government/Credit Float Adjusted Index, which includes all medium and larger issues of U.S. government, investment-grade corporate, and investment-grade international dollar-denominated bonds that have maturities between 1 and 5 years and are publicly issued.

• Vanguard Intermediate-Term Bond Index Fund tracks the performance of the Bloomberg U.S. 5-10 Year Government/Credit Float Adjusted Index, which includes all medium and larger issues of U.S. government, investment-grade corporate, and investment-grade international dollar-denominated bonds that have maturities between 5 and 10 years and are publicly issued.

The Index components are rebalanced by the index provider on a monthly basis and are likely to change over time. The following table shows the number of bonds held by each Fund, as well as the number of bonds in each Target Index, as of December 31, 2025:

Vanguard Fund	Number of Bonds Held	Number of Bonds in Target Index
Vanguard Total Bond Market Index Fund	11,444	13,940
Vanguard Short-Term Bond Index Fund	3,115	3,893
Vanguard Intermediate-Term Bond Index Fund	2,312	2,570

The Target Index is owned, calculated, and controlled by the index provider in its sole discretion. Neither the advisor nor any of their affiliates has discretion to select Target Index components or change a Target Index’s methodology.

Additional Information Regarding the Funds’ Investments

The Funds’ investments are described in more detail below.

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.   

All Funds.

• 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.

• 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.

• International Dollar-Denominated Bonds are U.S. dollar-denominated bonds issued by foreign governments, agencies and instrumentalities of foreign governments, foreign corporations, or U.S. affiliates of foreign corporations. Because the values of such bonds are designated in the U.S. dollar rather than the issuer’s local currency, it is the issuer that assumes the currency risk, usually to attract U.S. investors. As a result, the values of international dollar-denominated bonds are not affected directly by currency movements. However, if the foreign issuer’s local currency weakens significantly compared to the U.S. dollar, negative perceptions of the issuer’s ability to make payments could cause the issuer’s bonds to decline in value. Many issuers of international dollar-denominated bonds manage this risk by hedging their currency exposure, and their effectiveness in doing so is reflected in their credit rating.

Vanguard Total Bond Market Index Fund Only.

• 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.

• 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 Dollar Rolls are transactions in which a fund sells mortgage-backed securities to a dealer and simultaneously agrees to purchase similar securities in the future at a predetermined price. Entering into a mortgage dollar roll transaction has the potential to enhance a fund’s returns and reduce its administrative burdens compared to an investment

in a traditional mortgage-backed security. The use of mortgage dollar rolls may increase a fund’s portfolio turnover rate.

More on Fund Risks

Investing in the securities markets can result in a loss of principal. Each Fund is subject to a variety of risks, including the principal risks listed below, that can impact its net asset value (NAV), performance, and ability to achieve its investment objective.

More on Principal Risks

General Market Risk. The markets in which the 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 Funds’ investments, thereby resulting in potential losses to the Funds over short or long periods.

Investing in Bond Markets. Each 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 a 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.

may decline, which could result in a decline in a 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, a Fund’s income may decline because a 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 a Fund. In addition, negative perceptions of an issuer’s ability to make payments can cause the price of a security to decline. A 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.

Bond Liquidity Risk. If a 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. For example, liquidity in the corporate bond market may be impacted by overall market conditions or by a decline in the availability of credit.

Call Risk. Certain bonds held by a 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, a 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 a 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, a 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 a 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 (Vanguard Total Bond Index Fund). 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 (Vanguard Total Bond Index Fund). 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.

Index Investing. Each Fund is subject to the following risks associated with index investing: 

Passive Management. Each Fund seeks to track the performance of its Target index regardless of how the Target Index is performing. The advisor’s use of an indexing, or passive, approach to select and maintain investments for each Fund means that the advisor will select investments for the purpose of tracking the Target index and generally will not use strategies to reduce negative impacts to the Fund during periods of market volatility. As a result, a Fund’s performance may be lower than it would be if it were actively managed. 

Index Sampling Strategy. Because the Fund does not hold all of the securities included in its Target Index, it is subject to the risk that the representative sample of securities selected by the advisor will, in the aggregate, vary from the investment profile of the full Target Index.

Tracking Error. The performance of a Fund’s investments, in the aggregate, may not match the investment performance of its Target index. It is important to understand that an index fund will never perform exactly the same as its target index because, among other things, an index fund has operating expenses and transaction costs and its target index does not. Beyond these inherent differences in the operation of an index fund versus the operation of its target index, there are a variety of other factors that can cause or result in tracking error.These may include, but are not limited to: 

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Price differences between the securities held by the index fund and those included in its target index 

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Cash flows into or out of the index fund  

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The size of the index fund

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Compliance with new or existing regulatory requirements 

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Portfolio transactions carried out by the index fund’s advisor to minimize the distribution of capital gains 

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Changes to the underlying securities that make up the target index 

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Errors made by the provider of the target index

Tracking error risk may be heightened during times of increased market volatility or under other unusual market conditions. An index fund using a sampling strategy may be more likely to experience tracking error than an index fund using a replicating strategy. 

Index Provider. Each Fund is subject to risks associated with its index provider. The securities that make up a Target Index and their weighting in the Target Index are determined by the index provider. The index provider does not provide any warranty or accept any liability with respect to the quality, accuracy, or completeness of the Target Index or any data used to compile the Target Index. Under normal circumstances, the index provider rebalances (updates) the Target Index on a regular schedule. However, the index provider may also rebalance the Target Index outside of the regular schedule or delay or cancel a scheduled rebalance, which could result in added costs for a Fund or cause a Fund to experience tracking error. The index provider may make errors, and it is possible that such errors may not be identified by the index provider for a period of time or at all. Any gains, losses, or costs associated with or resulting from an error made by the index provider will generally be borne by a Fund and, as a result, a Fund’s shareholders. A Fund’s advisor does not provide any warranty or guarantee against any errors made by the index provider.

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 Funds, including the Funds’ abilities to transact in or obtain exposure to certain foreign securities and assets. Sanctions also could cause significant losses to the Funds’ investments and their 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 Funds 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.

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; see “Methods Used to Meet Redemption Requests” under Purchase, Redemption, and Exchange of Fund Shares in the Investing in Vanguard Funds section.

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 a 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.

Other Investment Policies

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

Substitute Index

Each Fund reserves the right to substitute a different index for an index it currently tracks if the current index is discontinued, if the Fund’s agreement with the provider of its Target index is terminated, or for any other reason determined in good faith by the Board. In any such instance, the substitute index would represent the same market segment as the Target index.

Other Types of Investments

Up to 20% of each Fund’s assets may be used to purchase 144A securities, which are nonpublic, investment-grade securities exempt from registration requirements under Rule 144A of the Securities Act of 1933, as well as smaller public issues or medium-term notes not included in a Fund’s Target Index because of the small size of the issue. The vast majority of such securities will have characteristics and risks similar to the bonds included in a Fund’s Target Index. Subject to the same 20% limit, each Fund may also purchase other investments that are not included in its Target Index (such as those described below) or may hold bonds that were included in the Target Index when acquired, but subsequently have been removed.

Vanguard Total Bond Market Index Fund may invest in or take short positions in To Be Announced (“TBA”) mortgage-backed securities. In addition, each Fund may invest in relatively conservative classes of collateralized mortgage obligations (CMOs), which offer a high degree of cash-flow predictability and a low level of vulnerability to mortgage prepayment risk. To reduce credit risk, these less-risky classes of CMOs are purchased only if they are issued by agencies of the U.S. government or issued by private companies that carry high-quality investment-grade ratings.

Each Fund may invest in 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. Each Fund may invest in derivatives only if the expected risks and rewards of the derivatives are consistent with the investment objective, policies, strategies, and risks of the Fund as disclosed in this Prospectus. In particular, derivatives will be used only when they may help the advisor to accomplish one or more of the following:

• Invest in eligible asset classes with greater efficiency and lower cost than is possible through direct investment.

• Add value when these instruments are favorably priced.

• Adjust sensitivity to changes in interest rates.

Each Fund may invest a small portion of its assets in shares of exchange-traded funds (ETFs). These ETFs typically provide returns similar to those of bonds. Each Fund may purchase ETFs when doing so will reduce the Fund’s transaction costs, facilitate cash management, mitigate risk, or have the

potential to add value because the instruments are favorably priced. Vanguard receives no additional revenue from Fund assets invested in ETF shares of other Vanguard funds. Fund assets invested in ETF shares of other Vanguard funds are excluded when allocating to a Fund its share of the costs of Vanguard’s operations.

Cash Management

Each 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, each 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

Each 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, a 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 when the Fund receives large cash flows that it cannot prudently invest immediately.

Portfolio Holdings

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

Management and Distribution of the Funds

Each 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

The Vanguard Group, Inc., P.O. Box 2600, Valley Forge, PA 19482, which began operations in 1975, serves as advisor to the Funds through Vanguard Capital Management (VCM). VCM exercises portfolio management responsibilities for the Funds. As of December 31, 2025, Vanguard served as advisor for approximately 9.9 trillion in assets. Vanguard, through VCM, provides investment advisory services to the Funds pursuant to the Funds’ Service Agreement and an intercompany service agreement between Vanguard and VCM, subject to the supervision and oversight of the trustees and officers of the Funds.

VCM, P.O. Box 2600, Valley Forge, PA 19482, is a wholly owned subsidiary of Vanguard and was established in 2025.

For the fiscal year ended December 31, 2025, the advisory expenses represented an effective annual rate of less than 0.01% of each Fund’s average net assets.

Each Fund reserves the right to utilize a multimanager approach in the future. 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 a Fund’s advisory arrangement will be communicated to shareholders in writing. As Vanguard is the Funds’ sponsor and overall manager, Vanguard, through VCM, may provide investment advisory services to a 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 Funds have 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 Funds may rely on the new SEC relief.

A discussion regarding the basis for the Board’s approval of each Fund’s investment advisory arrangement is available in each Fund’s Form N-CSR filed with the SEC for the fiscal period ended June 30 and in the applicable Financial Statements and Other Information document available on each Fund’s website.

The manager primarily responsible for the day-to-day management of the Funds is:

Joshua C. Barrickman, CFA, Principal of Vanguard, Portfolio Manager at VCM, and co-head of Vanguard’s Fixed Income Indexing Americas. He has been with Vanguard since 1998, has worked in investment management since 1999, has managed investment portfolios since 2005, has managed Vanguard Intermediate-Term Bond Index Fund since 2008; and has managed Vanguard Total Bond Market Index and Vanguard Short-Term Bond Index Funds since 2013. Education: B.S., Ohio Northern University; M.B.A., Lehigh University.

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

Investing in Vanguard Funds

In this section, you will find information regarding buying and selling Vanguard fund shares. Vanguard reserves the right to change the policies in this section without notice. Please call or visit our website for current information. See Contacting Vanguard.

The availability of certain Vanguard fund share classes and/or shareholder services described in this Prospectus will depend on the policies and procedures of the different accounts or investment products through which you hold your Vanguard fund shares. Vanguard fund shares can be held indirectly through financial intermediaries, or through investment products that use the funds as underlying investments such as employer-sponsored retirement or savings plans. In certain circumstances, Vanguard fund shares can be held directly with Vanguard.

If you hold Vanguard fund shares through accounts maintained by a financial intermediary, such as your securities dealer, broker, investment advisor, bank, other financial institution, including shares held in a brokerage account with Vanguard Brokerage Services®, or through an investment product such as an employer-sponsored retirement or savings plan, please consult your financial intermediary to determine which share classes are available to you and to learn about other rules that apply to your accounts. Your financial intermediary may impose rules that differ from, and/or charge a transaction or other fee in addition to, those described in this Prospectus. Please consult your financial intermediary for details. If you hold Vanguard fund shares through an employer-sponsored retirement or savings plan, your plan administrator or your employee benefits office can provide you with detailed information on how to participate in your plan and how to elect a Vanguard fund as an investment option.

If you hold Vanguard fund shares directly with Vanguard, you should carefully read each topic within this section that pertains to investing directly with Vanguard. Vanguard reserves the right, upon reasonable notice, to discontinue the ability to hold Vanguard fund shares directly with Vanguard for any or all investors and/or to transfer such shares to an affiliate or other financial institution. For more information regarding your account and the shareholder services offered through your account, you may contact Vanguard by phone, by mail, or through our website. See Contacting Vanguard.

fund in multiple accounts. Note that each reference to “you” in this Prospectus applies to any one or more registered account owners or persons authorized to transact on your account.

Share Classes and Converting Shares

Share Class Overview

Each Vanguard fund may offer one or more share classes. If a Vanguard fund offers multiple share classes, each share class has the same investment objective, strategies, and policies. However, because different share classes can have different expenses, their investment returns may differ. Vanguard and the Funds have received an exemptive order from the SEC that permits the Funds to offer conventional mutual fund shares and ETF shares. This Prospectus offers the Funds’ conventional mutual fund shares.

The following share classes are offered by the Funds:

• Investor Shares, offered by each Fund, which are generally available only to Vanguard funds that operate as funds of funds and to certain retirement plan clients that receive recordkeeping services from Vanguard. Other than these eligibility requirements, Investor Shares generally have no investment minimum.

• Admiral Shares, offered by each Fund, which generally require a minimum initial investment of $3,000.

• Institutional Shares, offered by each Fund, which generally require a minimum initial investment of $5 million.
• Institutional Plus Shares, offered by each Fund, which generally require a minimum initial investment of $100 million.

• Institutional Select Shares, offered by Vanguard Total Bond Market Index Fund, which generally require a minimum initial investment of $3 billion and are generally available only to institutional clients (such as defined contribution or benefit plans, endowments, foundations, and 529 plans).

• ETF Shares, which are an exchange-traded class of shares issued by each Fund.

You generally need a minimum of $1 to add to an existing account.

Additional eligibility requirements other than investment minimums may also apply to each share class. Investment minimums may differ for certain categories of accounts or investors. If you request a certain share class when you open a new account, but the investment amount does not meet the investment minimum for that share class, your investment may be placed in another share class of the Fund, as appropriate. Certain types of accounts may meet the investment minimum for certain share classes by aggregating separate accounts within the same fund.

Vanguard reserves the right, without notice, to change the eligibility requirements of its share classes, including changing the types of clients who are eligible to purchase each share class, increasing or decreasing the minimum amount required to open, convert shares to, or maintain a fund account, or increasing or decreasing the minimum amount required to add to an existing fund account.

Financial intermediaries, institutional clients, and Vanguard-advised clients should contact Vanguard for information on special eligibility rules that may apply to them.

Accounts Held Through Financial Intermediaries. If you hold shares through a financial intermediary (including shares held in a brokerage account through Vanguard Brokerage Services®), your financial intermediary may have different policies regarding the availability of certain share classes from those described above. You should consult your financial intermediary to consider your options, including your eligibility for the share classes described above.

Share Class Conversions

When a share class conversion occurs, you receive shares of one share class in place of shares of another class of the same fund. At the time of conversion, the dollar value of the “new” shares you receive equals the dollar value of the “old” shares that were converted. In other words, the conversion has no effect on the total dollar value of your investment in the fund at the time of the conversion. However, the number of shares you own after the conversion may be greater than or less than the number of shares you owned before the conversion, depending on the net asset values (NAVs) of the two share classes. A conversion between share classes of the same fund is a nontaxable event.

Conversions among Conventional Shares. You may be eligible for a self-directed conversion from one conventional (not exchange-traded) share class to another conventional share class (if available) of each Fund if your account meets all eligibility requirements for that share class. If you hold shares directly with Vanguard, you may request a conversion through our website (if you are registered for online access) or by telephone. Your conversion will be executed using the NAVs of the different share classes on the trade date after your conversion request is received in “good order.” For additional information on the requirements of “good order” and how the trade date is determined for a conversion request, please see “Good Order” and “Trade Date.” Vanguard will not accept your request to cancel any self-directed conversion request once processing has begun.

which the account is eligible. A decline in the account balance because of market movement may result in such a conversion. You will be notified before such mandatory conversion occurs.

Accounts Held Through Financial Intermediaries. If you hold shares through a financial intermediary (including shares held in a brokerage account through Vanguard Brokerage Services®), your financial intermediary may have different rules regarding conversion. You should consult with your financial intermediary to learn about the rules and to determine whether you are eligible to convert your shares.

Pricing of Fund Shares

When you purchase shares, you pay the share price, also known as the NAV, plus any applicable purchase fee. Your shares are also redeemed at the NAV, minus any applicable redemption fee. The share price for your transaction is the next one calculated after your purchase or redemption order is received in good order. 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. The time selected for NAV calculation in this rare event generally shall also serve as the conclusion of the trading day. 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.

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.

When the market quotations are not readily available or do not accurately reflect the value of a security or other investment, such security or other investment is priced at fair value, generally based on information provided by independent third-party pricing services, in accordance with the valuation policies and procedures adopted by the Vanguard funds’ boards of trustees. Fair value represents a good faith determination of the value of a fund’s investments. The fair value of a security or other investment is the amount that 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.

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.

Vanguard fund share prices are published daily on our website.

Purchase, Redemption, and Exchange of Fund Shares

How to Purchase, Redeem, and Exchange Shares

If you hold Vanguard fund shares through a financial intermediary (including shares held in a brokerage account through Vanguard Brokerage Services®), you should contact your financial intermediary to purchase, redeem, or exchange shares. Depending on the policies and procedures of your financial intermediary, the procedures and rules by which you open an account and/or purchase, redeem, and exchange shares may differ from the procedures and rules discussed below.

If you hold shares directly with Vanguard, please see the information below regarding purchasing, redeeming, and exchanging your shares.

How to Initiate a Purchase, Redemption, or Exchange Request

• Online or by telephone. You may open certain types of accounts, request a purchase, redemption, or exchange of your shares online through our website (if you are registered for online access), or by calling Vanguard. See Contacting Vanguard.

• By Mail. You may also send Vanguard your account registration form and check to open certain types of accounts. To add to an existing account, you may send your check with a purchase form. You may also send a form (available online) to Vanguard by mail to redeem from a fund account.

How to Pay for a Purchase

• By electronic bank transfer. You may purchase shares of a Vanguard fund through an electronic transfer of money from a bank account. To establish the electronic bank transfer service on a Vanguard account, you must designate the bank account online, complete a form, or fill out the appropriate section of your account registration form. After the service is set up on your account, you can purchase shares by electronic bank

transfer on a regular schedule (Automatic Investment Plan), if eligible, or upon request.

• By wire. Wiring instructions vary for different types of purchases. Please call Vanguard for instructions and policies on purchasing shares by wire. See Contacting Vanguard.

• By check. You may make initial or additional purchases to your fund account by sending a check with a purchase form. Make your check payable to Vanguard and include the appropriate fund number (e.g., Vanguard—XX). For a list of Fund numbers (for share classes in this Prospectus), see Additional Information. All purchase checks must be written in U.S. dollars, drawn on a U.S. bank, and accompanied by good order instructions. Vanguard does not accept cash, traveler’s checks, starter checks, or money orders. In addition, Vanguard may refuse checks that are not made payable to Vanguard.

• By exchange. You may purchase shares of a Vanguard fund using the proceeds from the simultaneous redemption of shares of another Vanguard fund.

How to Receive Redemption Proceeds

• By electronic bank transfer. You may have the proceeds of a fund redemption sent directly to a designated bank account. To establish the electronic bank transfer service on a Vanguard account, you must designate a bank account online, complete a form, or fill out the appropriate section of your account registration form. After the service is set up on your account, you can redeem shares by electronic bank transfer on a regular schedule (Automatic Withdrawal Plan), if eligible, or upon request.

• By wire. To receive your proceeds by wire, you may instruct Vanguard to wire your redemption proceeds ($100 minimum) to a previously designated bank account. To establish the wire redemption service, you generally must designate a bank account online, complete a form, or fill out the appropriate section of your account registration form.

• By exchange. You may have the proceeds of a Vanguard fund redemption invested directly in shares of another Vanguard fund.

• By check. You may have the proceeds of a fund redemption sent via check directly to you at the mailing address you have on file.
At your request, we can make your redemption check payable, or wire your redemption proceeds, to a different person or send it to a different address. However, this generally requires the written consent of all registered account owners and may require additional documentation, such as a signature guarantee or a notarized signature. You may obtain a signature guarantee from some commercial or savings banks, credit unions, trust companies, or member firms of a U.S. stock exchange.

If your account is eligible and you have established the checkwriting service on your account, you can redeem shares by writing a check for $250 or more.

Other Rules You Should Know

Responsibility for Fraud. You should take precautions to protect yourself from fraud. Keep your account-related information private, and review any account confirmations, statements, or other information that we provide to you as soon as you receive them. Let us know immediately if you discover unauthorized activity or see something on your account that you do not understand or that looks unusual. Vanguard will not be responsible for losses that result from transactions by a person who we reasonably believe is authorized to act on your account.

Account Service Fee. Vanguard may charge a $25 account service fee on fund accounts that have a balance below $5,000,000 for any reason, including market fluctuation. The account service fee may be applied to both retirement and nonretirement fund accounts and may be assessed on fund accounts in all Vanguard funds, regardless of the account minimum. The fee, which will be collected by redeeming fund shares in the amount of $25, will be deducted from fund accounts subject to the fee once per calendar year. Certain account types have alternative fee structures, including SIMPLE IRAs, Vanguard Retirement Investment Program pooled plans, and Vanguard Individual 401(k) Plans

Wire Fee. Please note that Vanguard charges a $10 wire fee for outgoing wire redemptions. The fee is assessed in addition to, rather than being withheld from, redemption proceeds and is paid directly to the fund in which you invest. For example, if you redeem $100 via a wire, you will receive the full $100, and the $10 fee will be assessed to your fund account through an additional redemption of fund shares. If you redeem your entire fund account, your redemption proceeds will be reduced by the amount of the fee. The wire fee may not apply to certain types of accounts. Please call or visit our website for more information on how the wire fee is charged.

No Cancellation. Vanguard will not accept your request to cancel any purchase, redemption or exchange request once processing has begun, so please be careful when placing a transaction request.

New Accounts. We are required by law to obtain from you certain personal information that we will use to verify your identity. If you do not provide the information, we may not be able to open your account. If we are unable to verify your identity, Vanguard reserves the right, without notice, to close your account or take such other steps as we deem reasonable. Certain types of accounts may require additional documentation.

Vanguard.com Registration. If you are a registered user of vanguard.com, you can review your account holdings; purchase, redeem, or exchange shares of most Vanguard funds; and perform most other transactions through our website. You must register for this service online.

Proof of a Caller’s Authority. We reserve the right to refuse a telephone request if the caller is unable to provide the requested information or if we reasonably believe that the caller is not an individual authorized to act on the account. Before we allow a caller to act on an account, we may request the following information:

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Authorization to act on the account (as the account owner or by legal documentation or other means).

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Account registration and address.

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Fund name and account number, if applicable.

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Other information relating to the caller, the account owner, or the account.

Unusual Circumstances. If you experience difficulty contacting Vanguard online or by telephone, you can send us your transaction request on a Vanguard form by regular or express mail.

Documentation for Certain Accounts. Special documentation may be required to redeem from certain types of accounts, such as trust, corporate, nonprofit, or retirement accounts. Please call us before attempting to redeem from these types of accounts.

Recently Purchased Shares. Although you can redeem shares at any time, proceeds may not be made available to you until the fund collects payment for your purchase. This may take up to seven calendar days for shares purchased by check or by electronic bank transfer. If you have written a check on a fund in an account with checkwriting privileges, that check may be rejected if your fund account does not have a sufficient available balance.

Address Change. If you change your address online or by telephone, there may be up to a 14-day restriction (starting on the business day after your address is changed) on your ability to request check redemptions online and by telephone. You can request a redemption in writing (using a form available online) at any time. Confirmations of address changes are sent to both the old and new addresses.

Future Trade-Date Requests. Vanguard does not accept requests to hold a purchase, conversion, redemption, or exchange transaction for a future date. All such requests will receive trade dates as described in Trade Date. Vanguard reserves the right to return future-dated purchase checks.

Uncashed Checks. Please cash your distribution or redemption checks promptly. Vanguard will not pay interest on uncashed checks. Vanguard may be required to transfer assets related to uncashed checks to a state under the state’s abandoned property law.

Invalid Addresses. If a dividend distribution or capital gains distribution check mailed to your address of record is returned as undeliverable, Vanguard will automatically reinvest the distribution and all future distributions back to the fund from which the distribution occurred until you provide us with a valid mailing address. Reinvestments will receive the NAV calculated on the date of the reinvestment.

Dormant Accounts. If your account has no activity in it for a period of time, Vanguard may be required to transfer it to a state under the state’s abandoned property law, subject to potential federal or state withholding taxes.

Accounts with More than One Owner. If an account has more than one owner or authorized person, Vanguard generally will accept instructions from any one owner or authorized person.

Share Certificates. Share certificates are no longer issued for Vanguard funds. Shares currently held in certificates cannot be redeemed, exchanged, converted, or transferred (reregistered) until you return the certificates (unsigned) to Vanguard by registered mail.

Earning Dividends. You generally begin earning dividends on the business day following your trade date of a purchase order. When buying money market fund shares through a federal funds wire on a business day, however, you generally can begin earning dividends immediately by making a purchase request by telephone to Vanguard before 10:45 a.m., Eastern time (2 p.m., Eastern time, for Vanguard Cash Reserves Federal Money Market Fund; 12:30 p.m., Eastern time, for Vanguard Federal Money Market Fund). For additional information on how the trade date is determined for a purchase order, please see “Trade Date”.

You generally will continue earning dividends until the first business day following your trade date of a redemption order. Generally, there are two exceptions to this rule: (1) If you redeem shares by writing a check against your account (if your account is eligible and you have established the checkwriting service on your account), the shares will stop earning dividends on the day that your check posts to your account; and (2) For money market funds, if you redeem shares with a same-day wire request before 10:45 a.m., Eastern time, on a business day (2 p.m., Eastern time, for Vanguard Cash Reserves Federal Money Market Fund; 12:30 p.m., Eastern time, for Vanguard Federal Money Market Fund), the shares will stop earning dividends that same day. For additional information on how the trade date is determined for a redemption order, please see “Trade Date”.

Additional Information Regarding Redemption of Shares

Methods Used to Meet Redemption Requests. Under normal circumstances, the Vanguard funds typically expect to meet redemptions with positive cash flows. When this is not an option, a fund seeks to maintain its risk exposure by selling a cross section of the fund’s holdings to meet redemptions, while also factoring in transaction costs. Additionally, a fund may work with larger clients to implement their redemptions in a manner that is least disruptive to the portfolio.

Under certain circumstances, including under stressed market conditions, there are additional tools that a 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. A fund may also suspend payment of redemption proceeds for up to seven days. Additionally under these unusual circumstances, a 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’ board of trustees. Redemptions in-kind may be used during both normal and stressed market conditions. For example, a fund may make a redemption in-kind if a cash redemption could negatively affect its operations or performance, as may be the case with large redemption amounts, or in situations where the redeeming shareholder may be engaged in market timing or frequent trading. A fund may delay payment of the redemption proceeds for up to seven calendar days.

Please contact Vanguard before you attempt to redeem a large dollar amount. In doing so, you may avoid in-kind or delayed payment of your redemption.

Emergency Circumstances. The Vanguard funds can postpone payment of redemption proceeds for up to seven calendar days. In addition, the Vanguard funds can suspend redemptions and/or postpone payments of redemption proceeds beyond seven calendar days at times when the NYSE is closed or during emergency circumstances or such other periods, as determined by the SEC.

in certain circumstances, investors may experience a longer settlement period at the time of the transaction. Please see Methods Used to Meet Redemption Requests and Emergency Circumstances for further information.

If you hold shares directly with Vanguard, the following rules also apply:

• Timing of wire redemptions from money market funds:for telephone requests received by Vanguard on a business day before 10:45 a.m., Eastern time (2 p.m., Eastern time, for Vanguard Cash Reserves Federal Money Market Fund; 12:30 p.m., Eastern time, for Vanguard Federal Money Market Fund), the redemption proceeds generally will leave Vanguard by the close of business the same day. For telephone requests received by Vanguard on a business day after those cut-off times, or on a nonbusiness day, and for all requests other than by telephone, the redemption proceeds generally will leave Vanguard by the close of business on the next business day.

• Timing of wire redemptions from all other funds: for requests received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the redemption proceeds generally will leave Vanguard by the close of business on the next business day. For requests received by Vanguard on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the redemption proceeds generally will leave Vanguard by the close of business on the second business day after Vanguard receives the request.

• If your redemption request is not in good order, it may be rejected. If we are unable to send your redemption proceeds by wire or electronic bank transfer because the receiving institution rejects the transfer, Vanguard will make additional efforts to complete your transaction. If Vanguard is still unable to complete the transaction, we may send the proceeds of the redemption to you by check, generally payable to all registered account owners, or use your proceeds to purchase new shares of the fund from which you sold shares for the purpose of the wire or electronic bank transfer transaction.

Good Order

Vanguard funds reserve the right to reject any transaction instructions that are not in “good order.” Good order generally means that your instructions:

• Are provided by the person(s) authorized in accordance with Vanguard’s policies and procedures to access the account and request transactions.

• Include the fund name and account number.

• Include the amount of the transaction (stated in dollars, shares, or percentage).

Written instructions also must generally be provided on a Vanguard form and include:

• Signature(s) and date from the authorized person(s).

• Signature guarantees or notarized signatures, if required for the type of transaction. (Call Vanguard for specific requirements.)

• Any supporting documentation that may be required.

Good order requirements may vary among different types of accounts and transactions. Vanguard reserves the right, without notice, to revise the requirements for good order. If you hold shares through a financial intermediary (including shares held in a brokerage account through Vanguard Brokerage Services®), please contact your financial intermediary for more details on good order requirements that may apply to you.

Trade Date

If you place your purchase, redemption, or exchange order through a financial intermediary (including through a brokerage account held at Vanguard Brokerage Services®), it is their responsibility to send your order to the Vanguard funds. Your transaction will be executed using the NAV next calculated after the order is received by the Vanguard funds in good order.

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.

If you hold shares directly with Vanguard, you may place your transaction request directly with Vanguard. Your transaction request will be executed using the NAV as calculated on the trade date as determined below. The trade date for any transaction request received in good order will depend on the day and time Vanguard receives your request, the manner in which you are transacting, and the type of fund in which you are transacting. If your transaction request is not in good order, it may be rejected.

Trade Date for a Purchase Order. For purchases by check into all funds other than money market funds and for purchases by exchange, wire, or electronic bank transfer into all funds: If the purchase request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date for the purchase will be the same day. If the purchase request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date for the purchase will be the next business day.

For purchases by check into money market funds: If the purchase request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date for the purchase will be the next business day. If the purchase request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date for the purchase will be the second business day following the day Vanguard receives the purchase request. Because money market instruments must be purchased with federal funds and it takes a money market mutual fund one business day to convert check proceeds into federal funds, the trade date for the purchase will be one business day later than for other funds.

Trade Date for a Redemption, Exchange, or Conversion Order (other than an order to convert to ETF Shares (if available)). If the transaction is received in good order on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will generally be the same day. If the transaction is received in good order on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will generally be the next business day.

Investing in Vanguard Funds through Employer-Sponsored Plans

If Vanguard fund shares are an investment option in your employer-sponsored retirement or savings plan, your plan administrator or your employee benefits office can provide you with detailed information on how to participate in your plan and how to elect a fund as an investment option.

Processing times for your transaction requests may differ among recordkeepers or among transaction and funding types. Your plan’s recordkeeper (which may also be Vanguard) will determine the necessary processing time frames for your transaction requests prior to submission to a fund. Consult your recordkeeper or plan administrator for more information.

If Vanguard is serving as your plan recordkeeper and if your transaction involves one or more investments with an early cut-off time for processing or another trading restriction, your entire transaction will be subject to the restriction when the trade date for your transaction is determined.

If you have questions about your account, contact your plan administrator or the organization that provides recordkeeping services for your plan. If you have any questions about the Vanguard funds or Vanguard, including those about a fund’s investment objective, strategies, or risks, contact Vanguard Participant Services toll-free at 800-523-1188 or visit our website at vanguard.com. Vanguard reserves the right to change its policies without notice to shareholders.

Shareholder Documents

When two or more shareholders have the same last name and address, just one summary prospectus (or prospectus) and/or shareholder report may be

sent in an attempt to eliminate the unnecessary expense of duplicate mailings. You may request individual prospectuses and reports by contacting our Client Services Department in writing, by telephone, or online. See Contacting Vanguard.

Confirmation Statements. If you hold shares directly with Vanguard, we will send (or provide through our website, whichever you prefer) a confirmation of your trade date and the amount of your transaction when you purchase, redeem, exchange, or convert shares. However, we will not send confirmations reflecting only checkwriting redemptions or the reinvestment of dividend or capital gains distributions. For any month in which you had a checkwriting redemption, a Checkwriting Activity Statement will be sent to you itemizing the checkwriting redemptions for that month. Promptly review each confirmation statement that we provide to you. It is important that you contact Vanguard immediately with any questions you may have about any transaction reflected on a confirmation statement, or Vanguard will consider the transaction properly processed.

If you hold shares through a financial intermediary (including shares held in a brokerage account through Vanguard Brokerage Services®), your financial intermediary will provide you with confirmation statements. Please contact your financial intermediary for details.

Portfolio Summaries. If you hold shares directly with Vanguard, we will send (or provide through our website, whichever you prefer) quarterly portfolio summaries to help you keep track of your accounts throughout the year. Each summary shows the market value of your account at the close of the statement period, as well as all distributions, purchases, redemptions, exchanges, transfers, and conversions for the current calendar quarter (or month). Promptly review each summary that we provide to you. It is important that you contact Vanguard immediately with any questions you may have about any transaction reflected on the summary, or Vanguard will consider the transaction properly processed.

Tax Information Statements. For most accounts, Vanguard (or your financial intermediary) is required to provide annual tax forms to assist you in preparing your income tax returns. These forms are generally available for each calendar year early in the following year. Registered users of vanguard.com can also view certain forms through our website. Vanguard (or your financial intermediary) may also provide you with additional tax-related documentation. For more information, consult our website at vanguard.com or see Contacting Vanguard.

Shareholder Reports and Financial Statements. Additional information about the Funds’ investments and performance is available in the Funds’ Annual and Semi-Annual Reports. The Funds’ financial statements are filed with the SEC on Form N-CSR and available on our website.

Electronic Delivery. Vanguard can deliver your account statements, transaction confirmations, prospectuses, certain tax forms, and shareholder reports electronically. If you are a registered user of vanguard.com, you can consent to the electronic delivery of these documents by logging on and changing your mailing preferences. You can revoke your electronic consent at any time through our website, and we will begin to send paper copies of these documents within 30 days of receiving your revocation.

If you hold shares through a financial intermediary (including shares held in a brokerage account through Vanguard Brokerage Services®), please contact your financial intermediary for electronic access to shareholder documents. Some financial intermediaries may not offer this service.

Reservation of Rights

In addition to the rights expressly stated elsewhere in this Prospectus, Vanguard reserves the following rights:

Right to Change Policies. Vanguard reserves the right, without notice, to (1) alter, add, or discontinue any conditions of purchase (including eligibility requirements), redemption, exchange, conversion, service, or privilege at any time and (2) alter, impose, discontinue, or waive any purchase fee, redemption fee, account service fee, or other fee charged to a shareholder or a group of shareholders. Changes may affect any or all investors. These actions will be taken when, at the sole discretion of Vanguard management, Vanguard believes they are in the best interest of a fund.

Account Restrictions. Vanguard reserves the right to: (1) redeem all or a portion of a fund/account to meet a legal obligation, including tax withholding, tax lien, garnishment order, or other obligation imposed on your account by a court or government agency; (2) redeem shares, close an account, or suspend account privileges, features, or options in the case of threatening conduct or activity; (3) redeem shares, close an account, or suspend account privileges, features, or options if Vanguard believes or suspects that not doing so could result in a suspicious, fraudulent, or illegal transaction; (4) place restrictions on the ability to redeem any or all shares in an account if it is required to do so by a court or government agency; (5) place restrictions on the ability to redeem any or all shares in an account if Vanguard believes that doing so will prevent fraud, financial exploitation or abuse, or to protect vulnerable investors when permitted by applicable law, regulations, or SEC guidance; (6) freeze any account and/or suspend account services if Vanguard has received reasonable notice of a dispute regarding the assets in an account, including notice of a dispute between the registered or beneficial account owners; and (7) freeze any account and/or suspend account services upon initial notification to Vanguard of the death of an account owner.

Right to Refuse or Reject Purchase Requests. Vanguard reserves the right to stop selling fund shares or to reject any purchase request at any time and without notice, including, but not limited to, purchases requested by exchange from another Vanguard fund. This also includes the right to reject any purchase request because the investor has a history of frequent trading or because the purchase may negatively affect a fund’s operation or performance (as may be the case with large purchase amounts).

Please contact Vanguard before you attempt to invest a large dollar amount. In doing so, you may avoid delayed or rejected transactions.

Exchange Privilege. Vanguard reserves the right, without notice, to revise or terminate the exchange privilege, limit the amount of any exchange, or reject an exchange, at any time, for any reason.

Please contact Vanguard before you attempt to exchange a large dollar amount. In doing so, you may avoid delayed or rejected transactions.

Account Liquidation. If an account no longer meets the eligibility requirements for a share class, a fund may, subject to applicable law, liquidate such fund account. Accounts with balances below the minimum amount required to maintain eligibility may be subject to liquidation, including when the decline results from market fluctuations or any other reason. This liquidation policy applies to nonretirement fund accounts and accounts that are held through financial intermediaries. You will be notified before a liquidation occurs.

Dividends, Distributions, and Taxes

Fund Distributions

Each Fund generally distributes to shareholders virtually all of its net income (interest less expenses) as well as any net short-term or long-term capital gains realized from the sale of its holdings. Each Fund may also make distributions that are treated as a return of capital. Income dividends generally are declared daily and distributed monthly; capital gains distributions, if any, generally occur annually in December. In addition, each Fund may make a supplemental distribution at some other time during the year.

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.

You can receive distributions of income or capital gains in cash, or you can have them automatically reinvested in more shares of the Fund. However, if you are investing through an employer-sponsored retirement or savings plan, your distributions will be automatically reinvested in additional Fund shares.

Basic Tax Points

Investors in taxable accounts should be aware of the following basic federal income tax points:

• Distributions are taxable to you whether or not you reinvest these amounts in additional Fund shares.

• Distributions declared and recorded in December—if paid to you by the end of January—are generally taxable as if received in December.

• Any income dividend distribution or short-term capital gains distribution that you receive is taxable to you as ordinary income.

• Any distribution of net long-term capital gains is taxable to you as long-term capital gains, no matter how long you have owned shares in the Fund.

• Capital gains distributions can occur when a Fund sells assets at a gain. Capital gains distributions vary from year to year as a result of the Fund’s investment activities and cash flows, including those due to redemption activity by Fund shareholders.

• Capital gains distributions may occur if Vanguard, a Fund, or its advisor makes changes that would impact the Fund directly or indirectly, including changes to the Fund’s portfolio or advisors or changes to any other Vanguard fund or product that would involve the redemption of shares of the Fund and the related sale of the Fund’s investments. Such changes could, depending on the timing, result in capital gains distributions in the current fiscal year, subsequent fiscal year, or both.

• Your cost basis in the Fund will be decreased by the amount of any return of capital that you receive. This, in turn, will affect the amount of any capital gain or loss that you realize when selling or exchanging your Fund shares.

• Return of capital distributions generally are not taxable to you until your cost basis has been reduced to zero. If your cost basis is at zero, return of capital distributions will be treated as capital gains.

• A sale or exchange of Fund shares is a taxable event. This means that you may have a capital gain to report as income, or a capital loss to report as a deduction, when you complete your tax return.

• Any conversion between classes of shares of the same fund is a nontaxable event. By contrast, an exchange between classes of shares of different funds is a taxable event.

• Vanguard (or your intermediary) will send you a statement each year showing the tax status of all of your distributions.

• If you purchase shares before an ex-dividend date when a fund has realized but not yet distributed income or capital gains, the purchase price may include the amount of the upcoming distribution, and you may pay the full price for the shares and later receive a portion of the purchase price back as a taxable distribution. In such case, you generally will be taxed upon receipt of such distribution, even though the distribution effectively represents a return of a portion of your purchase price. This is known as “buying a dividend.”

Individuals, trusts, and estates whose income exceeds certain threshold amounts are subject to a 3.8% Medicare contribution tax on “net investment income.” Net investment income takes into account distributions paid by the Fund and capital gains from any sale or exchange of Fund shares.

Income dividends and capital gains distributions that you receive, as well as your gains or losses from any sale or exchange of Fund shares, may be subject to state and local income taxes. Depending on your state’s rules, however, any dividends attributable to interest earned on direct obligations of the U.S. government may be exempt from state and local taxes. Vanguard will notify you each year how much, if any, of your dividends may qualify for this exemption.

This Prospectus provides general tax information only. If you are investing through a tax-advantaged account, such as an IRA or an employer-sponsored retirement or savings plan, special tax rules apply. Please consult your own tax advisor for detailed information about any tax consequences for you.

General Information

Backup Withholding. By law, Vanguard must withhold 24% of any taxable distributions or redemptions from your account if you do not:

• Provide your correct taxpayer identification number.

• Certify that the taxpayer identification number is correct.

• Confirm that you are not subject to backup withholding.

Similarly, Vanguard (or your intermediary) must withhold taxes from your account if the IRS instructs us to do so.

Special Notice to Non-U.S. Investors. The Funds offered for sale in this Prospectus are primarily intended to be made available to U.S. residents and may not be appropriate for investors taxable outside of the United States. Non-U.S. investors should visit the non-U.S. investors page on our website at global.vanguard.com for information about Vanguard’s non-U.S. products.

may apply to an investment in the Funds. Non-U.S. investors should consult their own tax advisors with respect to any particular U.S. or non-U.S. tax consequences of their investment in the Funds.

Frequent Trading Limitations

Overview

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 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.

Frequent Trading Policy

Each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) limits an investor’s purchases or exchanges into a fund account for 30 calendar days after the investor has redeemed or exchanged out of that fund account (“Frequent-Trading Limits”). ETF shares are not subject to these

Frequent-Trading Limits. For Vanguard Retirement Investment Program pooled plans, the Frequent-Trading Limits apply to exchanges made online or by telephone.

The Frequent-Trading Limits do not apply to the following:

• Purchases of shares with reinvested dividend or capital gains distributions.

• Transactions through Vanguard’s Automatic Investment Plan, Automatic Exchange Service, Direct Deposit Service, Automatic Withdrawal Plan, Required Minimum Distribution Service, Vanguard Small Business Online®, and certain transactions through intermediaries relating to systematic trades and required minimum distributions.

• Discretionary transactions through Vanguard Personal Advisor Services®, Vanguard Digital Advisor™, and discretionary (advisor-directed) transactions through certain intermediaries.

• Redemptions of shares to pay fund or account fees.

• Redemptions of shares to remove excess shareholder contributions to certain types of retirement accounts (including, but not limited to, IRAs, certain Individual 403(b)(7) Custodial Accounts, and Vanguard Individual 401(k) Plans).

• Transfers and reregistrations of shares within the same fund.

• Purchases of shares by asset transfer or direct rollover.

• Conversions of shares from one share class to another in the same fund.

• Checkwriting redemptions.

• Section 529 college savings plans.

• Certain approved institutional portfolios and asset allocation programs, as well as trades made by funds or trusts managed by Vanguard or its affiliates that invest in other Vanguard funds. (Please note that shareholders of Vanguard’s funds of funds are subject to the limitations.)

• Certain transactions below dollar value or other thresholds specified by Vanguard.

• In-kind transfers to a shareholder’s donor advised fund managed by Vanguard Charitable.

For participants in employer-sponsored defined contribution plans,* the Frequent-Trading Limits do not apply to:

• Purchases of shares with participant payroll or employer contributions or loan repayments.

• Purchases of shares with reinvested dividend or capital gains distributions.

• Distributions, loans, and in-service withdrawals from a plan.

• Redemptions of shares as part of a plan termination or at the direction of the plan.

• Transactions executed through the Vanguard Managed Account Program.

• Redemptions of shares to pay fund or account fees.

• Share or asset transfers or rollovers.

• Reregistrations of shares.

• Conversions of shares from one share class to another in the same fund.

• Exchange requests submitted by written request to Vanguard. (Exchange requests submitted by fax, if otherwise permitted, are subject to the limitations.)

*The following Vanguard fund accounts are also subject to the Frequent-Trading Limits: SEP-IRAs, SIMPLE IRAs, certain Individual 403(b)(7) Custodial Accounts, and Vanguard Individual 401(k) Plans.

Accounts Held by Institutions (Other Than Defined Contribution Plans). Vanguard will systematically monitor for frequent trading in institutional clients’ accounts. If we detect suspicious trading activity, we will investigate and take appropriate action, which may include applying to a client’s accounts the 30-day policy previously described, prohibiting a client’s purchases of fund shares, and/or revoking the client’s exchange privilege.

Accounts Held by Intermediaries. When intermediaries establish accounts in Vanguard funds for the benefit of their clients, we cannot always monitor the trading activity of the individual clients. However, we review trading activity at the intermediary (omnibus) level, and if we detect suspicious activity, we will investigate and take appropriate action. If necessary, Vanguard may prohibit additional purchases of fund shares by an intermediary, including for the benefit of certain of the intermediary’s clients. Intermediaries also may monitor their clients’ trading activities with respect to Vanguard funds.

For those Vanguard funds that charge purchase and/or redemption fees, intermediaries will be asked to assess these fees on client accounts and remit these fees to the funds. The application of purchase and redemption fees and Frequent-Trading Limits may vary among intermediaries. There are no assurances that Vanguard will successfully identify all intermediaries or that intermediaries will properly assess purchase and redemption fees or administer Frequent-Trading Limits. If you invest with Vanguard through an intermediary, please read that firm’s materials carefully to learn of any other rules or fees that may apply.

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.

Vanguard Total Bond Market Index Fund Investor Shares

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	$9.48	$9.71	$9.48	$11.19	$11.62
Investment Operations
Net Investment Income1	.367	.338	.289	.228	.202
Net Realized and Unrealized Gain (Loss) on Investments	.290	(.229)	.231	(1.702)	(.407)
Total from Investment Operations	.657	.109	.520	(1.474)	(.205)
Distributions
Dividends from Net Investment Income	(.367)	(.339)	(.290)	(.228)	(.201)
Distributions from Realized Capital Gains	—	—	—	(.008)	(.024)
Total Distributions	(.367)	(.339)	(.290)	(.236)	(.225)
Net Asset Value, End of Period	$9.77	$9.48	$9.71	$9.48	$11.19
Total Return2	7.03%	1.14%	5.60%	-13.25%	-1.77%
Ratios/Supplemental Data
Net Assets, End of Period (Millions)	$437	$518	$670	$795	$1,169
Ratio of Total Expenses to Average Net Assets	0.15%	0.15%	0.15%3	0.15%3	0.15%
Ratio of Net Investment Income to Average Net Assets	3.80%	3.52%	3.04%	2.26%	1.78%
Portfolio Turnover Rate4,5	38%	36%	36%	40%	69%

1	Calculated based on average shares outstanding.
2	Total returns do not include account service fees that may have applied in the periods shown. Fund prospectuses provide information about any applicable account service fees.
3	The ratio of expenses to average net assets for the period net of reduction from custody fee offset arrangements was 0.15%.
4	Excludes the value of portfolio securities received or delivered as a result of in-kind purchases or redemptions of the fund’s capital shares, including ETF Creation Units.
5	Includes 10%, 9%, 10%, 12%, and 34%, respectively, attributable to mortgage-dollar- roll activity.

Vanguard Short-Term Bond Index Fund Investor Shares

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	$10.13	$10.10	$9.87	$10.60	$10.87
Investment Operations
Net Investment Income1	.387	.330	.236	.133	.116
Net Realized and Unrealized Gain (Loss) on Investments	.210	.032	.230	(.726)	(.241)
Total from Investment Operations	.597	.362	.466	(.593)	(.125)
Distributions
Dividends from Net Investment Income	(.387)	(.332)	(.236)	(.134)	(.116)
Distributions from Realized Capital Gains	—	—	—	(.003)	(.029)
Total Distributions	(.387)	(.332)	(.236)	(.137)	(.145)
Net Asset Value, End of Period	$10.34	$10.13	$10.10	$9.87	$10.60
Total Return2	5.98%	3.64%	4.79%	-5.61%	-1.15%
Ratios/Supplemental Data
Net Assets, End of Period (Millions)	$39	$38	$53	$51	$74
Ratio of Total Expenses to Average Net Assets	0.15%	0.15%	0.15%3	0.15%3	0.15%
Ratio of Net Investment Income to Average Net Assets	3.77%	3.26%	2.37%	1.31%	1.08%
Portfolio Turnover Rate4	55%	56%	64%	41%	37%

1	Calculated based on average shares outstanding.
2	Total returns do not include account service fees that may have applied in the periods shown. Fund prospectuses provide information about any applicable account service fees.
3	The ratio of expenses to average net assets for the period net of reduction from custody fee offset arrangements was 0.15%.
4	Excludes the value of portfolio securities received or delivered as a result of in-kind purchases or redemptions of the fund’s capital shares, including ETF Creation Units.

Vanguard Intermediate-Term Bond Index Fund Investor Shares

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	$10.13	$10.36	$10.08	$11.89	$12.59
Investment Operations
Net Investment Income1	.415	.376	.311	.228	.221
Net Realized and Unrealized Gain (Loss) on Investments	.430	(.230)	.281	(1.806)	(.529)
Total from Investment Operations	.845	.146	.592	(1.578)	(.308)
Distributions
Dividends from Net Investment Income	(.415)	(.376)	(.312)	(.229)	(.219)
Distributions from Realized Capital Gains	—	—	—	(.003)	(.173)
Total Distributions	(.415)	(.376)	(.312)	(.232)	(.392)
Net Asset Value, End of Period	$10.56	$10.13	$10.36	$10.08	$11.89
Total Return2	8.46%	1.43%	5.99%	-13.34%	-2.44%
Ratios/Supplemental Data
Net Assets, End of Period (Millions)	$40	$45	$53	$63	$103
Ratio of Total Expenses to Average Net Assets	0.15%	0.15%	0.15%3	0.15%3	0.15%
Ratio of Net Investment Income to Average Net Assets	3.99%	3.67%	3.07%	2.13%	1.81%
Portfolio Turnover Rate4	55%	55%	63%	46%	46%

1	Calculated based on average shares outstanding.
2	Total returns do not include account service fees that may have applied in the periods shown. Fund prospectuses provide information about any applicable account service fees.
3	The ratio of expenses to average net assets for the period net of reduction from custody fee offset arrangements was 0.15%.
4	Excludes the value of portfolio securities received or delivered as a result of in-kind purchases or redemptions of the fund’s capital shares, including ETF Creation Units.

Additional Information

A Precautionary Note to Investment Companies. Each 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. Each 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. Each 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.

Securities Market Indexes
Listed below is the broad-based securities market index, as referenced in the Funds’ Average Annual Total Returns tables:

Bloomberg U.S. Aggregate Float Adjusted Index. An index that is the broadest representation 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 and maturities of 1 year or more. This Index weights its constituent securities based on the value of the constituent securities that are available for public trading, rather than the value of all constituent securities.

Vanguard Fund	Inception Date	Newspaper Abbreviation	Vanguard Fund Number	CUSIP Number
Vanguard Total Bond Market Index Fund
Investor Shares	12/11/1986	TotBd	84	921937108
Vanguard Short-Term Bond Index Fund
Investor Shares	3/1/1994	STBond	132	921937207
Vanguard Intermediate-Term Bond Index Fund
Investor Shares	3/1/1994	ITBond	314	921937306

Inception Date means the date on which the assets of a fund (or one of its share classes) 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.

CGS identifiers have been provided by CUSIP Global Services, managed on behalf of the American Bankers Association by FactSet Research Systems Inc., and are not for use or dissemination in a manner that would serve as a substitute for any CUSIP service. The CUSIP Database, © 2026 American Bankers Association. “CUSIP” is a registered trademark of the American Bankers Association.

CFA® is a registered trademark owned by CFA Institute.

“Bloomberg®” and Bloomberg U.S. Aggregate Float Adjusted Index, Bloomberg U.S. 1-5 Year Government/Credit Float Adjusted Index, and Bloomberg U.S. 5-10 Year Government/Credit Float Adjusted Index (the “Indices”) 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 Total Bond Market Index Fund, Vanguard Short-Term Bond Index Fund, and Vanguard Intermediate-Term Bond Index Fund (the “Funds”) are 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 Funds or any member of the public regarding the advisability of investing in securities or commodities generally or in the Funds particularly. The only relationship of Bloomberg to Vanguard is the licensing of certain trademarks, trade names and service marks and of the Indices, which are determined,

composed and calculated by BISL without regard to Vanguard or the Funds. Bloomberg has no obligation to take the needs of Vanguard or the owners of the Funds into consideration in determining, composing or calculating the Indices. Bloomberg is not responsible for and has not participated in the determination of the timing, price, or quantities of the Funds to be issued. Bloomberg shall not have any obligation or liability, including, without limitation, to customers of the Funds, in connection with the administration, marketing or trading of the Funds.

BLOOMBERG DOES NOT GUARANTEE THE ACCURACY AND/OR THE COMPLETENESS OF THE INDICES 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 FUNDS OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE INDICES 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 INDICES 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 FUNDS OR INDICES OR ANY DATA OR VALUES RELATING THERETO—WHETHER ARISING FROM THEIR NEGLIGENCE OR OTHERWISE, EVEN IF NOTIFIED OF THE POSSIBILITY THEREOF.

Contacting Vanguard

Web
Vanguard.com	For the most complete source of Vanguard news For fund, account, and service information For most account transactions For literature requests 24 hours a day, 7 days a week

Phone
Investor Information 800-662-7447 (Text telephone for people with hearing impairment at 800-749-7273)	For fund and service information For literature requests
Client Services 800-662-2739 (Text telephone for people with hearing impairment at 800-749-7273)	For account information For most account transactions
Participant Services 800-523-1188 (Text telephone for people with hearing impairment at 800-749-7273)	For information and services for participants in employer-sponsored plans
Institutional Division 800-523-1036	For information and services for large institutional investors
Financial Advisor and Intermediary Sales Support 800-997-2798	For information and services for financial intermediaries including financial advisors, broker-dealers, trust institutions, and insurance companies
Financial Advisory and Intermediary Trading Support 800-669-0498	For account information and trading support for financial intermediaries including financial advisors, broker-dealers, trust institutions, and insurance companies

Connect with Vanguard® ˃ vanguard.com

For More Information

If you would like more information about Vanguard Bond Index Funds, the following documents are available free upon request:

Annual/Semiannual Reports to Shareholders and Form N-CSR

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

Statement of Additional Information (SAI)

The SAI provides more detailed information about the Funds 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 Funds or other Vanguard funds, please visit https://vgi.vg/fund-literature or contact us as follows:

If you are an individual investor:
Telephone: 800-662-7447; Text telephone for people with hearing impairment: 800-749-7273

If you are a participant in an employer-sponsored plan: Telephone: 800-523-1188; Text telephone for people with hearing impairment: 800-749-7273

If you are a current Vanguard shareholder and would like information about your account, account transactions, and/or account statements, please call:

Client Services Department
Telephone: 800-662-2739; Text telephone for people with hearing impairment: 800-749-7273

Information Provided by the SEC

Reports and other information about the Funds 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.

Funds’ Investment Company Act file number: 811-04681

Vanguard Marketing Corporation, Distributor.

P 084 042026

April 28, 2026

Prospectus

Vanguard Bond Index Funds

Admiral™ Shares

Vanguard Total Bond Market Index Fund Admiral Shares (VBTLX)
Vanguard Short-Term Bond Index Fund Admiral Shares (VBIRX)
Vanguard Intermediate-Term Bond Index Fund Admiral Shares (VBILX)
Vanguard Long-Term Bond Index Fund Admiral Shares (VBLAX)

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
Vanguard Total Bond Market Index Fund	1
Vanguard Short-Term Bond Index Fund	7
Vanguard Intermediate-Term Bond Index Fund	13
Vanguard Long-Term Bond Index Fund	19
More on the Funds	25
Investment Objectives and More on Principal Investment Strategies	25
More on Fund Risks	31
Other Investment Policies	37
Portfolio Holdings	39
Management and Distribution of the Funds	39
Investing in Vanguard Funds	42
Share Classes and Converting Shares	43
Pricing of Fund Shares	45
Purchase, Redemption, and Exchange of Fund Shares	47
Reservation of Rights	57
Dividends, Distributions, and Taxes	59
Frequent Trading Limitations	61
Financial Highlights	65
Additional Information	69
Contacting Vanguard	72

Vanguard Total Bond Market Index Fund

Investment Objective

Vanguard Total Bond Market Index Fund (the “Fund”) seeks to track the performance of a broad, market-weighted bond index.

Fees and Expenses

The following tables describe the fees and expenses you may pay if you buy, hold, and sell Admiral Shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and example below.

Shareholder Fees
(Fees paid directly from your investment)


Sales Charge (Load) Imposed on Purchases	None
Purchase Fee	None
Sales Charge (Load) Imposed on Reinvested Dividends	None
Redemption Fee	None
Account Service Fee Per Year (for certain fund account balances below $5,000,000)	$25

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


Management Fees	0.03 %
12b-1 Distribution Fee	None
Other Expenses	0.01 %
Total Annual Fund Operating Expenses	0.04 %

Example

1 Year	3 Years	5 Years	10 Years
$4	$13	$23	$51

Portfolio Turnover

Principal Investment Strategies

Principal Risks

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’s Admiral Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Admiral Shares compare with those of a broad-based securities market index. Keep in mind that the Fund’s past

performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance.

Annual Total Returns — Vanguard Total Bond Market Index Fund Admiral Shares

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

	Total Return	Quarter
Highest	6.69 %	December 31, 2023
Lowest	-5.99 %	March 31, 2022

Average Annual Total Returns for Periods Ended December 31, 2025

	1 Year	5 Years	10 Years
Vanguard Total Bond Market Index Fund Admiral Shares
Return Before Taxes	7.15 %	-0.42 %	1.99 %
Return After Taxes on Distributions	5.46	-1.64	0.82
Return After Taxes on Distributions and Sale of Fund Shares	4.21	-0.84	1.02
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 Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and Portfolio Manager at VCM. He has managed the Fund since 2013.

Purchase and Sale of Fund Shares

If you invest directly with Vanguard, you may purchase or redeem shares online through our website (vanguard.com), by mail (The Vanguard Group, P.O. Box 982901, El Paso, TX 79998-2901), or by telephone (800-662-2739). The minimum investment amount required to open a Fund account for Admiral Shares is generally $3,000. The minimum investment amount required to add to an existing Fund account is generally $1.

Financial intermediaries, institutional clients, and Vanguard-advised clients should contact Vanguard for information on special eligibility rules that may apply to them regarding Admiral Shares. If you invest in Vanguard fund shares indirectly through an intermediary (including investing in shares through a brokerage account offered by Vanguard Brokerage Services®), please contact that firm directly for more information regarding your eligibility. If you invest in Vanguard fund shares through an employer-sponsored retirement or savings plan, your plan administrator or your benefits office can provide you with detailed information on how you can invest through your plan.

Tax Information

Payments to Financial Intermediaries

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

Vanguard Short-Term Bond Index Fund

Investment Objective

Vanguard Short-Term Bond Index Fund (the “Fund”) seeks to track the performance of a market-weighted bond index with a short-term dollar-weighted average maturity.

Fees and Expenses

Shareholder Fees
(Fees paid directly from your investment)


Sales Charge (Load) Imposed on Purchases	None
Purchase Fee	None
Sales Charge (Load) Imposed on Reinvested Dividends	None
Redemption Fee	None
Account Service Fee Per Year (for certain fund account balances below $5,000,000)	$25

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


Management Fees	0.05 %
12b-1 Distribution Fee	None
Other Expenses	0.01 %
Total Annual Fund Operating Expenses	0.06 %

Example

1 Year	3 Years	5 Years	10 Years
$6	$19	$34	$77

Portfolio Turnover

Principal Investment Strategies

Principal Risks

• Index Investing. The Fund is subject to risks associated with index investing. Because the Fund generally seeks to track the performance of the Target

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’s Admiral Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Admiral Shares compare with those of a broad-based securities market index and one or more additional indexes with similar investment characteristics as the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance.

Annual Total Returns — Vanguard Short-Term Bond Index Fund Admiral Shares

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

	Total Return	Quarter
Highest	3.48 %	September 30, 2024
Lowest	-3.40 %	March 31, 2022

Average Annual Total Returns for Periods Ended December 31, 2025

	1 Year	5 Years	10 Years
Vanguard Short-Term Bond Index Fund Admiral Shares
Return Before Taxes	6.08 %	1.52 %	2.11 %
Return After Taxes on Distributions	4.43	0.50	1.20
Return After Taxes on Distributions and Sale of Fund Shares	3.58	0.72	1.22
Bloomberg U.S. 1-5 Year Gov/Credit Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	6.11 %	1.56 %	2.17 %
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 Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and Portfolio Manager at VCM. He has 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.

Vanguard Intermediate-Term Bond Index Fund

Investment Objective

Vanguard Intermediate-Term Bond Index Fund (the “Fund”) seeks to track the performance of a market-weighted bond index with an intermediate-term dollar-weighted average maturity.

Fees and Expenses

Shareholder Fees
(Fees paid directly from your investment)


Sales Charge (Load) Imposed on Purchases	None
Purchase Fee	None
Sales Charge (Load) Imposed on Reinvested Dividends	None
Redemption Fee	None
Account Service Fee Per Year (for certain fund account balances below $5,000,000)	$25

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


Management Fees	0.05 %
12b-1 Distribution Fee	None
Other Expenses	0.01 %
Total Annual Fund Operating Expenses	0.06 %

Example

1 Year	3 Years	5 Years	10 Years
$6	$19	$34	$77

Portfolio Turnover

Principal Investment Strategies

Principal Risks

• Index Investing. The Fund is subject to risks associated with index investing. Because the Fund generally seeks to track the performance of the Target

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’s Admiral Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Admiral Shares compare with those of a broad-based securities market index and one or more additional indexes with similar investment characteristics as the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance.

Annual Total Returns — Vanguard Intermediate-Term Bond Index Fund Admiral Shares

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

	Total Return	Quarter
Highest	6.87 %	December 31, 2023
Lowest	-6.26 %	March 31, 2022

Average Annual Total Returns for Periods Ended December 31, 2025

	1 Year	5 Years	10 Years
Vanguard Intermediate-Term Bond Index Fund Admiral Shares
Return Before Taxes	8.56 %	-0.20 %	2.47 %
Return After Taxes on Distributions	6.78	-1.49	1.22
Return After Taxes on Distributions and Sale of Fund Shares	5.03	-0.69	1.38
Bloomberg U.S. 5-10 Year Gov/Credit Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	8.76 %	-0.15 %	2.55 %
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 Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and Portfolio Manager at VCM. He has managed the Fund since 2008.

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.

Vanguard Long-Term Bond Index Fund

Investment Objective

Vanguard Long-Term Bond Index Fund (the “Fund”) seeks to track the performance of a market-weighted bond index with a long-term dollar-weighted average maturity.

Fees and Expenses

Shareholder Fees
(Fees paid directly from your investment)


Sales Charge (Load) Imposed on Purchases	None
Purchase Fee	0.50 %
Sales Charge (Load) Imposed on Reinvested Dividends	None
Redemption Fee	None
Account Service Fee Per Year (for certain fund account balances below $5,000,000)	$25

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


Management Fees	0.05 %
12b-1 Distribution Fee	None
Other Expenses	0.01 %
Total Annual Fund Operating Expenses	0.06 %

Example

1 Year	3 Years	5 Years	10 Years
$56	$69	$84	$127

Portfolio Turnover

Principal Investment Strategies

The Fund employs an indexing investment approach designed to track the performance of the Bloomberg U.S. Long Government/Credit Float Adjusted Index (the “Target Index”), which includes all medium and larger issues of U.S. government, investment-grade corporate, and investment-grade international dollar-denominated bonds that have maturities of greater than 10 years and are publicly issued. Under normal circumstances, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in the bonds that make up the Target Index.

Principal Risks

• Index Investing. The Fund is subject to risks associated with index investing. Because the Fund generally seeks to track the performance of the Target

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’s Admiral Shares (including annual fund operating expenses but excluding shareholder fees) has varied from one calendar year to another over the periods shown. If applicable shareholder fees were reflected, returns would be less than those shown in the bar chart. The table shows how the average annual total returns of the Admiral Shares (including annual fund operating expenses and any applicable shareholder fees) compare with those of a broad-based securities market index and one or more additional indexes with similar investment characteristics as the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance.

Annual Total Returns — Vanguard Long-Term Bond Index Fund Admiral Shares

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

	Total Return	Quarter
Highest	13.11 %	December 31, 2023
Lowest	-12.27 %	June 30, 2022

Average Annual Total Returns for Periods Ended December 31, 2025

	1 Year	5 Years	Since Fund Inception	Fund Inception Date
Vanguard Long-Term Bond Index Fund Admiral Shares				02/07/2019
Return Before Taxes	6.02 %	-4.99 %	0.67 %
Return After Taxes on Distributions	4.04	-6.53	-0.99
Return After Taxes on Distributions and Sale of Fund Shares	3.54	-4.29	-0.08
Bloomberg U.S. Long Gov/Credit Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	6.62 %	-4.89 %	0.76 %
Bloomberg U.S. Aggregate Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	7.21	-0.37	1.90

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

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 Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and Portfolio Manager at VCM. He has 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 Total Bond Market Index Fund

• Vanguard Short-Term Bond Index Fund

• Vanguard Intermediate-Term Bond Index Fund

• Vanguard Long-Term Bond Index Fund

Each Fund is a series of Vanguard Bond Index Funds (the “Trust”). Reading this Prospectus will help you decide whether a Fund is the right investment for you.

Investment Objectives and More on Principal Investment Strategies

Investment Objectives

The Funds’ investment objectives are as follows:

dollar-weighted average maturity.
• Vanguard Long-Term Bond Index Fund seeks to track the performance of a market-weighted bond index with a long-term dollar-weighted average maturity.

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

Implementation of Investment Objectives

To achieve its investment objective, each Fund employs an indexing, or passive, investment approach designed to track its Target Index.

Vanguard Fund	Target Index
Vanguard Total Bond Market Index Fund	Bloomberg U.S. Aggregate Float Adjusted Index
Vanguard Short-Term Bond Index Fund	Bloomberg U.S. 1-5 Year Government/Credit Float Adjusted Index
Vanguard Intermediate-Term Bond Index Fund	Bloomberg U.S. 5-10 Year Government/Credit Float Adjusted Index
Vanguard Long-Term Bond Index Fund	Bloomberg U.S. Long Government/Credit Float Adjusted Index

The Target Indexes for Vanguard Short-Term, Vanguard Intermediate-Term, and Vanguard Long-Term Bond Index Funds are subsets of the Bloomberg U.S. Aggregate Float Adjusted Index.

What are Index Funds?

Index funds attempt to track—not outperform—the performance of a

specified market index. An index is a group of securities whose overall

performance is used as a standard to measure the investment

performance of a particular market. Some indexes represent entire

markets, such as the U.S. stock market, while others cover a segment of a

market, such as short-term bonds.

One cannot invest directly in an index. Instead, an index fund’s advisor will

typically seek to hold all, or substantially all, of the securities that make up

the fund’s target index (often referred to as “replicating” an index or a “full

replication” approach) or a representative sample of the securities that

make up a fund’s target index (“sampling” an index).

Index. Under normal circumstances, Vanguard Total Bond Market Index Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in the bonds that make up the Target Index and in securities that the advisor determines have substantially identical economic characteristics to the securities that make up the Target Index. Investments in derivatives may be counted toward a Fund’s 80% policy to the extent that they provide investment exposure to the securities included within the policy or to one or more market risk factors associated with such securities. Each Fund may change its 80% policy only upon 60 days’ notice to shareholders.

Security Selection

Each Fund invests by sampling its Target Index. The advisor buys and sells securities for the Fund for the purpose of tracking the Target Index.

Using quantitative and qualitative methods, each Fund’s advisor generally selects a representative sample of securities that approximates the Fund’s full Target Index in terms of key risk factors and other characteristics. These factors include duration, cash flow, quality, and callability of the underlying bonds. In addition, each Fund keeps industry sector and subsector exposure within tight boundaries relative to its Target Index. Because each Fund does not hold all of the securities included in its Target Index, some of the securities (and issuers) that are held will likely be overweighted (or underweighted) compared with its Target Index. The maximum overweight (or underweight) is constrained at the issuer level with the goal of producing well-diversified exposure in the portfolio.

Each Target Index is described below:

• Vanguard Long-Term Bond Index Fund tracks the performance of the Bloomberg U.S. Long Government/Credit Float Adjusted Index, which includes all medium and larger issues of U.S. government, investment-grade corporate, and investment-grade international dollar-denominated bonds that have maturities of greater than 10 years and are publicly issued.

The index components are rebalanced by the index provider on a monthly basis and are likely to change over time. The following table shows the number of bonds held by each Fund, as well as the number of bonds in each Target Index, as of December 31, 2025:

Vanguard Fund	Number of Bonds in Fund	Number of Bonds in Target Index
Vanguard Total Bond Market Index Fund	11,444	13,940
Vanguard Short-Term Bond Index Fund	3,115	3,893
Vanguard Intermediate-Term Bond Index Fund	2,312	2,570
Vanguard Long-Term Bond Index Fund	2,936	3,571

The Target Indexes are owned, calculated, and controlled by the index provider in its sole discretion. Neither the advisor nor any of its affiliates has discretion to select Target Index components or change a Target Index’s methodology.