Post-effective Amendment (investment Company, Rule 485(b)) (485bpos)

Name	Symbol	Market	Type
Vanguard Short Term Bond	AMEX:BSV	AMEX	Exchange Traded Fund

	Price Change	% Change	Price	High Price	Low Price	Open Price	Traded	Last Trade
	0.00	0.00%	77.40				0	09:18:30

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT
(NO. 33-06001)

UNDER THE SECURITIES ACT OF 1933

☒

Pre-Effective Amendment No.__

□

Post-Effective Amendment No. 87

☒

and

REGISTRATION STATEMENT
(NO. 811-04681)

UNDER THE INVESTMENT COMPANY ACT OF 1940

Amendment No. 89

☒

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

Anne E. Robinson, Esquire
P.O. Box 876

Valley Forge, PA 19482

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

□	immediately upon filing pursuant to paragraph (b)
☒	on April 28, 2020, pursuant to paragraph (b)
□	60 days after filing pursuant to paragraph (a)(1)
□	on (date) pursuant to paragraph (a)(1)
□	75 days after filing pursuant to paragraph (a)(2)
□	on (date) pursuant to paragraph (a)(2) of rule 485 If appropriate, check the following box:
□	This post-effective amendment designates a new effective date for a previously filed post-effective amendment.

Vanguard Bond Index Funds

Prospectus

April 28, 2020

Investor Shares & Admiral™ Shares

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

See the inside front cover for important information about access to your fund’s annual and semiannual shareholder reports.

This prospectus contains financial data for the Funds through the fiscal year ended December 31, 2019.

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.

Important information about access to shareholder reports

Beginning on January 1, 2021, as permitted by regulations adopted by the SEC, paper copies of your fund’s annual and semiannual shareholder reports will no longer be sent to you by mail, unless you specifically request them. Instead, you will be notified by mail each time a report is posted on the website and will be provided with a link to access the report.

If you have already elected to receive shareholder reports electronically, you will not be affected by this change and do not need to take any action. You may elect to receive shareholder reports and other communications from the fund electronically by contacting your financial intermediary (such as a broker-dealer or bank) or, if you invest directly with the fund, by calling Vanguard at one of the phone numbers on the back cover of this prospectus or by logging on to vanguard.com.

You may elect to receive paper copies of all future shareholder reports free of charge. If you invest through a financial intermediary, you can contact the intermediary to request that you continue to receive paper copies. If you invest directly with the fund, you can call Vanguard at one of the phone numbers on the back cover of this prospectus or log on to vanguard.com. Your election to receive paper copies will apply to all the funds you hold through an intermediary or directly with Vanguard.

Contents

Vanguard Fund Summaries
Total Bond Market Index Fund	1
Short-Term Bond Index Fund	7
Intermediate-Term Bond Index Fund	12
Long-Term Bond Index Fund	17
Investing in Index Funds	22
More on the Funds	23
The Funds and Vanguard	36
Investment Advisor	36
Dividends, Capital Gains, and Taxes	37
Share Price	39
Financial Highlights	41

Investing With Vanguard	48
Purchasing Shares	48
Converting Shares	52
Redeeming Shares	54
Exchanging Shares	58
Frequent-Trading Limitations	59
Other Rules You Should Know	61
Fund and Account Updates	65
Employer-Sponsored Plans	66
Contacting Vanguard	68
Additional Information	69
Glossary of Investment Terms	72

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Vanguard Total Bond Market Index Fund

Investment Objective

The Fund seeks to track the performance of a broad, market-weighted bond index.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold Investor Shares or Admiral Shares of the Fund.

Shareholder Fees
(Fees paid directly from your investment)

	Admiral Shares	Investor Shares
Sales Charge (Load) Imposed on Purchases	None	None
Purchase Fee	None	None
Sales Charge (Load) Imposed on Reinvested Dividends	None	None
Redemption Fee	None	None
Account Service Fee Per Year (for certain fund account balances below $10,000)	$20	None

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

	Admiral Shares	Investor Shares
Management Fees	0.04%	0.14%
12b-1 Distribution Fee	None	None
Other Expenses	0.01%	0.01%
Total Annual Fund Operating Expenses	0.05%	0.15%

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Examples

The following examples are intended to help you compare the cost of investing in the Fund’s Investor Shares or Admiral Shares with the cost of investing in other mutual funds. They illustrate the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund's shares. These examples assume that the shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you were to redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years	5 Years	10 Years
Admiral Shares	$5	$16	$28	$64
Investor Shares	$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 more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense examples, reduce the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 31% 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 Barclays U.S. Aggregate Float Adjusted Index. This Index measures the performance of a wide spectrum of public, investment-grade, taxable, fixed income securities 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.

The Fund invests by sampling the Index, meaning that it holds a broadly diversified collection of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund's investments will be selected through the sampling process, and at least 80% of the Fund's assets will be invested in bonds held in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index. As of December 31, 2019, the dollar-weighted average maturity of the Index was 8.2 years.

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Principal Risks

An investment in the Fund could lose money over short or long periods of time. You should expect the Fund's share price and total return to fluctuate within a wide range. The Fund is subject to the following risks, which could affect the Fund's performance, and the level of risk may vary based on market conditions:

• Interest rate risk, which is the chance that bond prices will decline because of rising interest rates. Interest rate risk should be moderate for the Fund because it invests primarily in short- and intermediate-term bonds, whose prices are less sensitive to interest rate changes than are the prices of long-term bonds.

• Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk is generally high for short-term bond funds and moderate for intermediate-term bond funds, so investors should expect the Fund’s monthly income to fluctuate accordingly.

• Prepayment risk, which is the chance that during periods of falling interest rates, homeowners will refinance their mortgages before their maturity dates, resulting in prepayment of mortgage-backed securities held by the Fund. The Fund would then lose any price appreciation above the mortgage’s principal and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund's income. Such prepayments and subsequent reinvestments would also increase the Fund’s portfolio turnover rate. Prepayment risk should be moderate for the Fund.

• Extension risk, which is the chance that during periods of rising interest rates, certain debt securities will be paid off substantially more slowly than originally anticipated, and the value of those securities may fall. This will lengthen the duration or average life of those securities and delay a fund’s ability to reinvest proceeds at higher interest rates, making a fund more sensitive to changes in interest rates. For funds that invest in mortgage-backed securities, there is a chance that during periods of rising interest rates, homeowners will repay their mortgages at slower rates. Extension risk should be moderate for the Fund.

• Call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. The Fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund‘s income. Such redemptions and subsequent reinvestments would also increase the Fund‘s portfolio turnover rate. Call risk should be low for the Fund because it invests only a small portion of its assets in callable bonds.

• Credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline. Credit risk

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should be low for the Fund because it purchases only bonds that are of investment-grade quality.

• Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.

• Liquidity risk, which is the chance that the Fund may not be able to sell a security in a timely manner at a desired price.

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 are intended to help you understand the risks of investing in the Fund. Because the eligibility requirements for the Fund's Admiral Shares were recently changed, annual total returns for the Fund's Admiral Shares are relevant for most investors. Accordingly, the information presented in the bar chart reflects the performance of the Fund's Admiral Shares. 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 share classes presented compare with those of the Fund's target index, which has investment characteristics similar to those of 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 or by calling Vanguard toll-free at 800-662-7447.

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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	4.01%	September 30, 2011
Lowest	-3.17%	December 31, 2016

Average Annual Total Returns for Periods Ended December 31, 2019

	1 Year	5 Years	10 Years
Vanguard Total Bond Market Index Fund Admiral Shares
Return Before Taxes	8.71%	3.00%	3.68%
Return After Taxes on Distributions	7.49	1.87	2.50
Return After Taxes on Distributions and Sale of Fund Shares	5.14	1.79	2.36
Vanguard Total Bond Market Index Fund Investor Shares
Return Before Taxes	8.61%	2.90%	3.57%
Bloomberg Barclays U.S. Aggregate Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	8.87%	3.07%	3.78%

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 shown only for the Admiral Shares and may differ for each share class. 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.

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Investment Advisor

The Vanguard Group, Inc. (Vanguard)

Portfolio Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’s Fixed Income Indexing Americas. He has managed the Fund since 2013.

Purchase and Sale of Fund Shares

You may purchase or redeem shares online through our website (vanguard.com), by mail (The Vanguard Group, P.O. Box 1110, Valley Forge, PA 19482-1110), or by telephone (800-662-2739). The minimum investment amount required to open and maintain a Fund account for Admiral Shares is $3,000. The minimum investment amount required to add to an existing Fund account is generally $1. 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. 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 are investing through an intermediary, please contact that firm directly for more information regarding your eligibility. If you are investing 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

The Fund’s distributions may be taxable as ordinary income or capital gain. 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.

Payments to Financial Intermediaries

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

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Vanguard Short-Term Bond Index Fund

Investment Objective

The Fund seeks to track the performance of a market-weighted bond index with a short-term dollar-weighted average maturity.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold Investor Shares or Admiral Shares of the Fund.

Shareholder Fees
(Fees paid directly from your investment)

	Admiral Shares	Investor Shares
Sales Charge (Load) Imposed on Purchases	None	None
Purchase Fee	None	None
Sales Charge (Load) Imposed on Reinvested Dividends	None	None
Redemption Fee	None	None
Account Service Fee Per Year (for certain fund account balances below $10,000)	$20	None

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

	Admiral Shares	Investor Shares
Management Fees	0.06%	0.14%
12b-1 Distribution Fee	None	None
Other Expenses	0.01%	0.01%
Total Annual Fund Operating Expenses	0.07%	0.15%

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Examples

	1 Year	3 Years	5 Years	10 Years
Admiral Shares	$7	$23	$40	$90
Investor Shares	$15	$48	$85	$192

Portfolio Turnover

Principal Investment Strategies

The Fund employs an indexing investment approach designed to track the performance of the Bloomberg Barclays U.S. 1–5 Year Government/Credit Float Adjusted Index. This Index 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.

The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund’s investments will be selected through the sampling process, and at least 80% of the Fund’s assets will be invested in bonds held in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index. As of December 31, 2019, the dollar-weighted average maturity of the Index was 2.8 years.

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Principal Risks

The Fund is designed for investors with a low tolerance for risk, but you could still lose money by investing in it. The Fund is subject to the following risks, which could affect the Fund's performance, and the level of risk may vary based on market conditions:

• Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk is generally high for short-term bond funds, so investors should expect the Fund's monthly income to fluctuate.

• Interest rate risk, which is the chance that bond prices will decline because of rising interest rates. Interest rate risk should be low for the Fund because it invests primarily in short-term bonds, whose prices are less sensitive to interest rate changes than are the prices of longer-term bonds.

• Liquidity risk, which is the chance that the Fund may not be able to sell a security in a timely manner at a desired price.

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

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website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

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	1.84%	June 30, 2010
Lowest	-1.12%	December 31, 2016

Average Annual Total Returns for Periods Ended December 31, 2019

	1 Year	5 Years	10 Years
Vanguard Short-Term Bond Index Fund Admiral Shares
Return Before Taxes	4.86%	1.95%	2.03%
Return After Taxes on Distributions	3.90	1.20	1.31
Return After Taxes on Distributions and Sale of Fund Shares	2.87	1.16	1.28
Vanguard Short-Term Bond Index Fund Investor Shares
Return Before Taxes	4.77%	1.87%	1.94%
Bloomberg Barclays U.S. 1-5 Year Gov/Credit Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	5.01%	2.03%	2.13%

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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)

Portfolio Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’s Fixed Income Indexing Americas. He has managed the Fund since 2013.

Purchase and Sale of Fund Shares

Tax Information

Payments to Financial Intermediaries

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

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Vanguard Intermediate-Term Bond Index Fund

Investment Objective

The Fund seeks to track the performance of a market-weighted bond index with an intermediate-term dollar-weighted average maturity.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold Investor Shares or Admiral Shares of the Fund.

Shareholder Fees
(Fees paid directly from your investment)

	Admiral Shares	Investor Shares
Sales Charge (Load) Imposed on Purchases	None	None
Purchase Fee	None	None
Sales Charge (Load) Imposed on Reinvested Dividends	None	None
Redemption Fee	None	None
Account Service Fee Per Year (for certain fund account balances below $10,000)	$20	None

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

	Admiral Shares	Investor Shares
Management Fees	0.06%	0.12%
12b-1 Distribution Fee	None	None
Other Expenses	0.01%	0.03%
Total Annual Fund Operating Expenses	0.07%	0.15%

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Examples

	1 Year	3 Years	5 Years	10 Years
Admiral Shares	$7	$23	$40	$90
Investor Shares	$15	$48	$85	$192

Portfolio Turnover

Principal Investment Strategies

The Fund employs an indexing investment approach designed to track the performance of the Bloomberg Barclays U.S. 5–10 Year Government/Credit Float Adjusted Index. This Index 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.

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Principal Risks

• Interest rate risk, which is the chance that bond prices will decline because of rising interest rates. Interest rate risk should be moderate for the Fund because it invests primarily in intermediate-term bonds, whose prices are less sensitive to interest rate changes than are the prices of long-term bonds.

• Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk is generally moderate for intermediate-term bond funds, so investors should expect the Fund’s monthly income to fluctuate accordingly.

• Liquidity risk, which is the chance that the Fund may not be able to sell a security in a timely manner at a desired price.

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

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perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

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	5.35%	June 30, 2010
Lowest	-4.15%	December 31, 2016

Average Annual Total Returns for Periods Ended December 31, 2019

	1 Year	5 Years	10 Years
Vanguard Intermediate-Term Bond Index Fund Admiral Shares
Return Before Taxes	10.18%	3.53%	4.77%
Return After Taxes on Distributions	8.94	2.31	3.38
Return After Taxes on Distributions and Sale of Fund Shares	6.01	2.17	3.19
Vanguard Intermediate-Term Bond Index Fund Investor Shares
Return Before Taxes	10.09%	3.45%	4.68%
Bloomberg Barclays U.S. 5-10 Year Gov/Credit Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	10.38%	3.64%	4.85%

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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)

Portfolio Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’s Fixed Income Indexing Americas. He has managed the Fund since 2008.

Purchase and Sale of Fund Shares

Tax Information

Payments to Financial Intermediaries

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

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Vanguard Long-Term Bond Index Fund

Investment Objective

The Fund seeks to track the performance of a market-weighted bond index with a long-term dollar-weighted average maturity.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold Admiral Shares of the Fund.

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 $10,000)	$20

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


Management Fees	0.07%
12b-1 Distribution Fee	None
Other Expenses	0.00%
Total Annual Fund Operating Expenses	0.07%

Example

The following example is intended to help you compare the cost of investing in Fund’s Admiral Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund's shares. This example assumes that the shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you were to redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

1 Year	3 Years	5 Years	10 Years
$57	$72	$89	$139

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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 more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 33% 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 Barclays U.S. Long Government/Credit Float Adjusted Index. This Index 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.

Principal Risks

• Interest rate risk, which is the chance that bond prices will decline because of rising interest rates. Interest rate risk should be high for the Fund because it invests primarily in long-term bonds, whose prices are more sensitive to interest rate changes than are the prices of shorter-term bonds.

• Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk should be low for the Fund because it invests primarily in long-term bonds.

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• Liquidity risk, which is the chance that the Fund may not be able to sell a security in a timely manner at a desired price.

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 are intended to help you understand the risks of investing in the Fund. The Fund's Admiral Shares have not been in operation long enough to report a full calendar-year return. Performance of the Fund's Admiral Shares would be substantially similar to that of the ETF Shares because both share classes constitute an investment in the same portfolio of securities; therefore, their returns generally should differ only to the extent that the expenses of the two share classes differ. The bar chart shows how the performance of the Fund‘s ETF Shares (based on NAV) has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the ETF Shares compare with those of the Fund's target index, which has investment characteristics similar to those of the Fund. If Admiral Shares were reflected in the bar chart and table, returns would be less than those shown. 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 or by calling Vanguard toll-free at 800-662-7447.

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

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

	Total Return	Quarter
Highest	15.94%	September 30, 2011
Lowest	-8.31%	December 31, 2016

Average Annual Total Returns for Periods Ended December 31, 2019

	1 Year	5 Years	10 Years
Vanguard Long-Term Bond Index Fund ETF Shares
Based on NAV
Return Before Taxes	19.09%	5.35%	7.55%
Return After Taxes on Distributions	17.30	3.63	5.70
Return After Taxes on Distributions and Sale of Fund Shares	11.24	3.31	5.16
Based on Market Price
Return Before Taxes	18.98	5.30	7.56
Bloomberg Barclays U.S. Long Gov/Credit Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	19.59%	5.42%	7.59%

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.

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Investment Advisor

The Vanguard Group, Inc. (Vanguard)

Portfolio Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’s Fixed Income Indexing Americas. He has managed the Fund since 2013.

Purchase and Sale of Fund Shares

You may purchase or redeem shares online through our website (vanguard.com), by mail (The Vanguard Group, P.O. Box 1110, Valley Forge, PA 19482-1110), or by telephone (800-662-2739). The minimum investment amount required to open and maintain a Fund account for Admiral Shares is $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 are investing through an intermediary, please contact that firm directly for more information regarding your eligibility. If you are investing 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 investment advisor do not pay financial intermediaries for sales of Fund shares.

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Investing in Index Funds

What Is Indexing?

Indexing is an investment strategy for tracking the performance of a specified market benchmark, or “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. There are many types of indexes. Some represent entire markets—such as the U.S. stock market or the U.S. bond market. Other indexes cover market segments—such as small-capitalization stocks or short-term bonds. One cannot invest directly in an index.

The index sponsor determines the securities to include in the index and the weighting of each security in the index. Under normal circumstances, the index sponsor will rebalance an index on a regular schedule. An index sponsor may carry out additional ad hoc index rebalances, delay or cancel a scheduled rebalance. Generally, the index sponsor does not provide any warranty, or accept any liability, with respect to the quality, accuracy, or completeness of either the target index or its related data. Errors made by the index sponsor may occur from time to time and may not be identified by the index sponsor for a period of time or at all. Vanguard does not provide any warranty or guarantee against such errors. Therefore, the gains, losses, or costs associated with the index sponsor’s errors will generally be borne by the index fund and its shareholders.

An index fund seeks to hold all, or a representative sample, of the securities that make up its target index. Index funds attempt to mirror the performance of the target index, for better or worse. However, an index fund generally does not perform exactly like its target index. For example, index funds have operating expenses and transaction costs. Market indexes do not, and therefore they will usually have a slight performance advantage over funds that track them. The ability of an index fund to match its performance to that of its target index can also be impacted by, among other things, the timing and size of cash flows and the size of the fund. Market disruptions and regulatory restrictions could also have an adverse effect on a fund’s ability to adjust its exposure to the required levels in order to track the index.

Index funds typically have the following characteristics:

• Variety of investments. Index funds generally invest in the securities of a variety of companies and industries.

• Relative performance consistency. Because they seek to track market benchmarks, index funds usually do not perform dramatically better or worse than their benchmarks.

• Low cost. Index funds are generally inexpensive to run compared with actively managed funds. They have low or no research costs and typically keep trading activity— and thus dealer markups and other transaction costs—to a minimum compared with actively managed funds.

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More on the Fund

symbol throughout the prospectus. It is used to mark detailed information about the more significant risks that you would confront as a Fund shareholder. To highlight terms and concepts important to mutual fund investors, we have provided Plain Talk^® explanations along the way. Reading the prospectus will help you decide whether the Fund is the right investment for you. We suggest that you keep this prospectus for future reference.

Share Class Overview

This prospectus offers the Fund's Institutional Select Shares, which are generally for investors who invest a minimum of $3 billion. A separate prospectus offers the Fund’s Admiral™ Shares, which generally have an investment minimum of $3,000, and Investor Shares, 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. Another prospectus offers the Fund’s Institutional Shares and Institutional Plus Shares, which are generally for investors who invest a minimum of $5 million and $100 million, respectively. In addition, the Fund issues ETF Shares (an exchange-traded class of shares), which are also offered through a separate prospectus.

All share classes offered by the Fund have the same investment objective, strategies, and policies. However, different share classes have different expenses; as a result, their investment returns will differ.

Plain Talk About Costs of Investing

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The following sections explain the principal investment strategies and policies that the Fund uses in pursuit of its objective. The Fund's board of trustees, which oversees the Fund's management, may change investment strategies or policies in the interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental. The Fund‘s policy of investing at least 80% of its assets in bonds that are part of its target index may be changed only upon 60 days‘ notice to shareholders.

Market Exposure

The Fund is subject to interest rate risk, which is the chance that bond prices will decline because of rising interest rates. Interest rate risk should be moderate for the Fund because it invests primarily in short- and intermediate- term bonds, whose prices are less sensitive to interest rate changes than are the prices of long-term bonds.

How Interest Rate Changes Affect the Value of a $1,000 Bond¹

Type of Bond (Maturity)	After a 1% Increase	After a 1% Decrease	After a 2% Increase	After a 2% Decrease
Short-Term (2.5 years)	$977	$1,024	$954	$1,049
Intermediate-Term (10 years)	922	1,086	851	1,180
Long-Term (20 years)	874	1,150	769	1,328

1 Assuming a 4% coupon rate.

These figures are for illustration only; you should not regard them as an indication of future performance of the bond market as a whole or the Fund in particular.

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Plain Talk About Bonds and Interest Rates

Changes in interest rates can affect bond income as well as bond prices.

The Fund is subject to income risk, which is the chance that the Fund’s income will decline because of falling interest rates. A fund‘s income declines when interest rates fall because the fund then must invest new cash flow and cash from maturing bonds in lower-yielding bonds. Income risk is generally high for short-term bond funds and moderate for intermediate-term bond funds, so investors should expect the Fund‘s monthly income to fluctuate accordingly.

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Plain Talk About Bond Maturities

Although falling interest rates tend to strengthen bond prices, they can cause other problems for bond fund investors—bond calls and prepayments.

The Fund is subject to prepayment risk, which is the chance that during periods of falling interest rates, homeowners will refinance their mortgages before their maturity dates, resulting in prepayment of mortgage-backed securities held by the Fund. The Fund would then lose any price appreciation above the mortgage’s principal and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund’s income. Such prepayments and subsequent reinvestments would also increase the Fund’s portfolio turnover rate. Prepayment risk should be moderate for the Fund.

The Fund is subject to extension risk, which is the chance that during periods of rising interest rates, certain debt securities will be paid off substantially more slowly than originally anticipated, and the value of those securities may fall. This will lengthen the duration or average life of those securities held by the Fund and delay the Fund’s ability to reinvest proceeds at higher interest rates, making the Fund more sensitive to changes in interest rates. For funds that invest in mortgage-backed securities, there is a chance that during periods of rising interest rates, homeowners will repay their mortgages at slower rates. Extension risk should be moderate for the Fund.

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The Fund is subject to call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. The Fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund’s income. Such redemptions and subsequent reinvestments would also increase the Fund’s portfolio turnover rate. Call risk should be low for the Fund.

The Fund is subject to credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline.

Plain Talk About Credit Quality

The credit quality of the Fund is expected to be very high, and thus credit risk is expected to be low.

To a limited extent, the Fund is subject to event risk, which is the chance that corporate fixed income securities held by the Fund may suffer a substantial decline in credit quality and market value because of a restructuring of the companies that issued the securities or because of other factors negatively affecting the issuers.

The Fund is subject to liquidity risk, which is the chance that the Fund may not be able to sell a security in a timely manner at a desired price.

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Security Selection

Index sampling strategy. Because it would be very expensive and inefficient to buy and sell all securities held in its target index, the Fund uses index “sampling” techniques to select securities. Using computer programs, the Fund’s advisor generally selects a representative sample of securities that approximates the 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, the Fund keeps industry sector and subsector exposure within tight boundaries relative to its target index. Because the 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 the target index. The maximum overweight (or underweight) is constrained at the issuer level with the goal of producing well-diversified credit exposure in the portfolio.

The Fund is subject to index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.

The number of bonds held by the Fund and the number of bonds in the Fund’s target index were 9,033 and 10,982, respectively, as of December 31, 2019.

Types of bonds. The Fund tracks the Bloomberg Barclays U.S. Aggregate Float Adjusted Index. The Bloomberg Barclays U.S. Aggregate Float Adjusted Index measures the performance of a wide spectrum of public, investment-grade, taxable, fixed income securities 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.

As of December 31, 2019, the Fund was composed of the following types of bonds:

U.S. Government/Agency	Corporate	Mortgage- Backed	International Dollar- Denominated	Other	Total
43.3%	29.6%	22.3%	4.1%	0.7%	100%

An explanation of each type of bond follows:

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• Corporate bonds are IOUs 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; a company whose credit rating is not strong will have to offer a higher interest rate to obtain buyers for its bonds. For purposes of the preceding table, corporate bonds include securities that are backed by a pool of underlying assets (asset-backed securities) or commercial mortgages (commercial mortgage-backed bonds). The Fund expects to purchase only investment-grade corporate bonds.

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mortgage-backed securities and have the potential to enhance a fund’s returns and reduce its administrative burdens, compared with holding mortgage-backed securities directly. These transactions may increase a fund’s portfolio turnover rate. Mortgage dollar rolls will be used only to the extent that they are consistent with the Fund’s investment objective and risk profile.

• International dollar-denominated bonds are bonds denominated in U.S. dollars and issued by foreign governments and companies. To the extent that the Fund owns foreign bonds, it is subject to country risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by companies in foreign countries. In addition, the prices of foreign bonds and the prices of U.S. bonds have, at times, moved in opposite directions. Because the bond’s value is designated in dollars rather than in the currency of the issuer’s country, the investor is not exposed to currency risk; rather, the issuer assumes that risk, usually to attract U.S. investors. Although currency movements do not affect the value of international dollar-denominated bonds directly, they could affect the value indirectly by adversely affecting the issuer’s ability (or the market’s perception of the issuer’s ability) to pay interest or repay principal.

Plain Talk About U.S. Government-Sponsored Entities

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Other Investment Policies and Risks

The Fund will invest at least 80% of its assets in bonds held in its target index. Up to 20% of the Fund’s assets may be used to purchase nonpublic, investment-grade securities, generally referred to as 144A securities, as well as smaller public issues or medium-term notes not included in the index because of the small size of the issue. The Fund's advisor expects that the vast majority of these securities will have characteristics similar to those in the target index. Subject to the same 20% limit, the Fund may also purchase other investments that are outside of its target index or may hold bonds that, when acquired, were included in the index but subsequently were removed. The Fund may also 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.

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

The Fund may invest, to a limited extent, in derivatives. Generally speaking, 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. Investments in derivatives may subject the Fund to risks different from, and possibly greater than, those of investments directly in the underlying securities or assets. The Fund will not use derivatives for speculation or for the purpose of leveraging (magnifying) investment returns.

The Fund may invest a small portion of its assets in fixed income futures, which are a type of derivative, and/or shares of exchange-traded funds (ETFs). These fixed income futures and ETFs typically provide returns similar to those of the bonds listed in the index, or in a subset of the index, the Fund seeks to track. The Fund may purchase futures or 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 are excluded when allocating to the Fund its share of the costs of Vanguard operations.

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Cash Management

The Fund's daily cash balance may be invested in Vanguard Market Liquidity Fund and/or Vanguard Municipal Cash Management Fund (each, a CMT Fund), which are low-cost money market funds. When investing in a CMT Fund, the Fund bears its proportionate share of the expenses of the CMT Fund in which it invests. Vanguard receives no additional revenue from Fund assets invested in a CMT Fund.

Methods Used to Meet Redemption Requests

Under normal circumstances, the Fund typically expects to meet redemptions with positive cash flows. When this is not an option, the Fund seeks to maintain its risk exposure by selling a cross section of the Fund’s holdings to meet redemptions, while also factoring in transaction costs. Additionally, the Fund may work with larger clients to implement their redemptions in a manner that is least disruptive to the portfolio; see “Potentially disruptive redemptions” under Redeeming Shares in the Investing With Vanguard section.

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

Temporary Investment Measures

The Fund may temporarily depart from its normal investment policies and strategies when the advisor believes that doing so is in the Fund's best interest, so long as the strategy or policy employed is consistent with the Fund's investment objective. For instance, the Fund may invest beyond its normal limits in derivatives or exchange-traded funds that are consistent with the Fund's investment objective when those instruments are more favorably priced or provide needed liquidity, as might be the case when the Fund receives large cash flows that it cannot prudently invest immediately.

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Frequent Trading or Market-Timing

• Certain Vanguard funds charge shareholders purchase and/or redemption fees on transactions.

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See the Investing With Vanguard section of this prospectus for further details on Vanguard’s transaction policies.

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

Turnover Rate

Although the Fund generally seeks to invest for the long term, it may sell securities regardless of how long they have been held. Generally, an index fund sells securities in response to redemption requests from shareholders of conventional (not exchange-traded) shares or to changes in the composition of its target index or in an effort to manage the fund’s duration. The Financial Highlights section of this prospectus shows historical turnover rates for the Fund. A turnover rate of 100%, for example, would mean that the Fund had sold and replaced securities valued at 100% of its net assets within a one-year period. Shorter-term bonds will mature or be sold—and need to be replaced—more frequently than longer-term bonds. As a result, shorter-term bond funds tend to have higher turnover rates than longer-term bond funds. In general, the greater the turnover rate, the greater the impact transaction costs will have on a fund’s return. Also, funds with high turnover rates may be more likely to generate capital gains, including short-term capital gains, that must be distributed to shareholders and will be taxable to shareholders investing through a taxable account.

The Fund and Vanguard

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

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Plain Talk About Vanguard’s Unique Corporate Structure

Investment Advisor

The Vanguard Group, Inc., P.O. Box 2600, Valley Forge, PA 19482, which began operations in 1975, serves as advisor to the Fund through its Fixed Income Group. As of December 31, 2019, Vanguard served as advisor for approximately $5 trillion in assets. Vanguard provides investment advisory services to the Fund pursuant to the Funds’ Service Agreement and subject to the supervision and oversight of the trustees and officers of the Fund.

For the fiscal year ended December 31, 2019, the advisory expenses represented an effective annual rate of less than 0.01% of the Fund’s average net assets.

Under the terms of an SEC exemption, the Fund's board of trustees may, without prior approval from shareholders, change the terms of an advisory agreement with a third-party investment advisor or hire a new third-party investment advisor—either as a replacement for an existing advisor or as an additional advisor. Any significant change in the Fund's advisory arrangements will be communicated to shareholders in writing. As the Fund's sponsor and overall manager, Vanguard may provide investment advisory services to the Fund at any time. Vanguard may also recommend to the board of trustees that an advisor be hired, terminated, or replaced or that the terms of an existing advisory agreement be revised. The Fund has filed an application seeking a similar SEC exemption with respect to investment advisors that are wholly owned subsidiaries of Vanguard. If the exemption is granted, the Fund may rely on the new SEC relief.

For a discussion of why the board of trustees approved the Fund's investment advisory arrangement, see the most recent semiannual report to shareholders covering the fiscal period ended June 30.

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

Joshua C. Barrickman, CFA, Principal of Vanguard 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, and has managed the Fund since 2013. Education: B.S., Ohio Northern University; M.B.A., Lehigh University.

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

Dividends, Capital Gains, and Taxes

Fund Distributions

The Fund 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. Income dividends generally are declared daily and distributed monthly; capital gains distributions, if any, generally occur annually in December. In addition, the Fund may occasionally make a supplemental distribution at some other time during the year. You can receive distributions of income or capital gains in cash, or you can have them automatically reinvested in more shares of the Fund.

Plain Talk About Distributions

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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 in December—if paid to you by the end of January—are 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 may vary considerably from year to year as a result of the Fund's normal investment activities and cash flows.

• 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.

This prospectus provides general tax information only. If you are investing through a tax-advantaged account, such as a 401(k) plan, special tax rules apply. Please consult your tax advisor for detailed information about any tax consequences for you.

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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.

Foreign investors. Vanguard funds offered for sale in the United States (Vanguard U.S. funds), including the Fund offered in this prospectus, are not widely available outside the United States. Non-U.S. investors should be aware that U.S. withholding and estate taxes and certain U.S. tax reporting requirements may apply to any investments in Vanguard U.S. funds. Foreign investors should visit the non-U.S. investors page on our website at vanguard.com for information on Vanguard’s non-U.S. products.

Share Price

Share price, also known as net asset value (NAV), is 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, the Fund reserves the right to treat such day as a business day and calculate NAVs 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. 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. On U.S. holidays or other days when the NYSE is closed, the NAV is not calculated, and the Fund does not sell or redeem shares. However, on those days the value of the 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).

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Vanguard fund share prices are published daily on our website at vanguard.com/prices.

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Financial Highlights

Vanguard Total Bond Market Index Fund Institutional Select Shares

	Year Ended December 31,			June 24, 2016¹ to Dec. 31, 2016
For a Share Outstanding Throughout Each Period	2019	2018	2017	June 24, 2016¹ to Dec. 31, 2016
Net Asset Value, Beginning of Period	$10.45	$10.75	$10.65	$11.03
Investment Operations
Net Investment Income	0.306²	0.295²	0.275²	0.135
Net Realized and Unrealized Gain (Loss) on Investments	0.600	(0.298)	0.105	(0.375)
Total from Investment Operations	0.906	(0.003)	0.380	(0.240)
Distributions
Dividends from Net Investment Income	(0.306)	(0.294)	(0.275)	(0.135)
Distributions from Realized Capital Gains	—	(0.003)	(0.005)	(0.005)
Total Distributions	(0.306)	(0.297)	(0.280)	(0.140)
Net Asset Value, End of Period	$11.05	$10.45	$10.75	$10.65
Total Return	8.76%	0.01%	3.60%	–2.20%
Ratios/Supplemental Data
Net Assets, End of Period (Millions)	$20,401	$14,821	$12,031	$5,438
Ratio of Total Expenses to Average Net Assets	0.01%	0.01%	0.01%	0.01%³
Ratio of Net Investment Income to Average Net Assets	2.81%	2.82%	2.56%	2.41%³
Portfolio Turnover Rate^4,5	31%	54%	55%	61%⁶

1	Inception.
2	Calculated based on average shares outstanding.

3	Annualized.
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%, 13%, 15%, and 23% attributable to mortgage-dollar-roll activity.
6	Reflects the fund’s portfolio turnover for the fiscal year ended December 31, 2016.

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Investing With Vanguard

This section of the prospectus explains the basics of doing business with Vanguard. Vanguard fund shares can be held directly with Vanguard or indirectly through an intermediary, such as a bank, a broker, or an investment advisor. If you hold Vanguard fund shares directly with Vanguard, you should carefully read each topic within this section that pertains to your relationship with Vanguard. If you hold Vanguard fund shares indirectly through an intermediary (including shares held in a brokerage account through Vanguard Brokerage Services^®), please see Investing With Vanguard Through Other Firms, and also refer to your account agreement with the intermediary for information about transacting in that account. Vanguard reserves the right to change the following policies without notice. Please call or check online for current information. See Contacting Vanguard.

For Vanguard fund shares held directly with Vanguard, each fund you hold in an account is a separate “fund account.” For example, if you hold three funds in a corporate account and offer six funds in a defined contribution plan account, you have two fund accounts—and this is true even if you hold the same 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.

For Plan Participants

If Institutional Select Shares of the Fund are an investment option in your 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 the Fund as an investment option. If you have any questions about the Fund or Vanguard, including those about the Fund’s investment objective, strategies, or risks, contact Vanguard Participant Services toll-free at 800-523-1188.

• If you have questions about your account, contact your plan administrator or the organization that provides recordkeeping services for your plan.

• Be sure to carefully read each topic that pertains to plan participant transactions with Vanguard.

Vanguard reserves the right to change its policies without notice to shareholders.

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Investment Options and Allocations

Your plan’s specific provisions may allow you to change your investment selections, the amount of your contributions, or the allocation of your contributions among the investment choices available to you. Contact your plan administrator or employee benefits office for more details.

See Plan Participant Transactions.

Purchasing Shares

Vanguard reserves the right, without notice, to increase or decrease the minimum amount required to open, convert shares to, or maintain a fund account or to add to an existing fund account.

Investment minimums may differ for certain categories of investors.

Account Minimums for Institutional Select Shares

To open and maintain an account. Generally $3 billion. Available only to institutional clients (such as defined contribution or benefit plans, endowments, foundations, and 529 plans). If you request Institutional Select Shares when you open a new account but the investment amount does not meet the account minimum for Institutional Select Shares, your investment will be placed in another share class of the Fund, as appropriate.

Investment minimums may differ for a Vanguard collective investment trust with a similar mandate.

How to Initiate a Purchase Request

Be sure to check Exchanging Shares, Frequent-Trading Limitations, and Other Rules You Should Know before placing your purchase request.

New clients interested in purchasing Institutional Select Shares in a fund account should contact their Vanguard Sales Executive or call 800-523-1036.

Existing clients interested in purchasing additional shares or exchanging shares may make a request by contacting their Vanguard Relationship Manager, submitting a request through a trading platform, or making a request by mail (Vanguard, P.O. Box 1101, Valley Forge, PA 19482-1101).

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To add to an existing account. Generally $1.

Transaction Fees on Purchases

The Fund reserves the right to charge a 0.25% transaction fee to investors whose aggregate share purchases into the Fund exceed $500 million. The Fund may impose this transaction fee if an investor’s aggregate purchases into the Fund over a 12-month period exceed, or are expected to exceed, the indicated amount upon notice to the client in conjunction with a purchase that triggers application of the fee. The fee will be assessed only if the client elects to proceed with the purchase. Generally, this fee will not apply to transactions coordinated in advance between a client and Vanguard.

How to Pay for a Purchase

By electronic bank transfer or wire. You may purchase Institutional Select Shares by an electronic bank transfer or by wire. Wiring instructions vary for different types of purchases. Please contact your Vanguard Relationship Manager or Vanguard Sales Executive for instructions and policies on purchasing shares by wire. See Contacting Vanguard.

Your purchase or exchange request can be initiated online (if you are registered for online access), by telephone, or by mail. All new and existing clients are encouraged to contact their Vanguard Relationship Manager or Vanguard Sales Executive to discuss options for purchasing or exchanging shares.

Trade Date

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determined at Vanguard’s discretion), generally 4 p.m., Eastern time. The time selected for NAV calculation in this rare event shall also serve as the conclusion of the trade date. See Share Price.

If your purchase request is not accurate and complete, it may be rejected. See Other Rules You Should Know—Good Order.

For further information about purchase transactions, consult our website at vanguard.com or see Contacting Vanguard.

Earning Dividends

Other Purchase Rules You Should Know

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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.

Large purchases. Call Vanguard before attempting to invest a large dollar amount.

No cancellations. Vanguard will not accept your request to cancel any purchase request once processing has begun. Please be careful when placing a purchase request.

Converting Shares

Vanguard will not accept your request to cancel any self-directed conversion request once processing has begun. Please be careful when placing a conversion request.

A conversion between share classes of the same fund is a nontaxable event.

Trade Date

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unavailable, as determined at Vanguard’s discretion), generally 4 p.m., Eastern time. The time selected for NAV calculation in this rare event shall also serve as the conclusion of the trade date. See Share Price.

Conversions to Institutional Select Shares

You are eligible for a self-directed conversion from another share class to Institutional Select Shares of the Fund, provided that your account meets all eligibility requirements. You may request a conversion through our website (if you are registered for online access), through a trading platform, by mail, or by telephone. Accounts that qualify for Institutional Select Shares will not be automatically converted.

Mandatory Conversions to Another Share Class

Redeeming Shares

How to Initiate a Redemption Request

Be sure to check Exchanging Shares, Frequent-Trading Limitations, and Other Rules You Should Know before placing your redemption request.

Online. You may request a redemption of shares or request an exchange through our website if you are registered for online access. In addition, clients may also process redemption requests through a trading platform.

By telephone. You may call your Vanguard Relationship Manager or Vanguard Client Account Manager to request a redemption of shares or an exchange. See Contacting Vanguard.

By mail. You may send a form (available online) to Vanguard to redeem from a fund account or to make an exchange.

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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. Your redemption request can be initiated online (if you are registered for online access), by telephone, or by mail.

By wire. To receive your proceeds by wire, you may instruct Vanguard to wire your redemption proceeds 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.

Trade Date

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If your redemption request is received in good order, we typically expect that redemption proceeds will be paid by the Fund within one business day of the trade date; however, in certain circumstances, investors may experience a longer settlement period at the time of the transaction. For further information, see “Potentially disruptive redemptions” and “Emergency circumstances.”

For further information about redemption transactions, consult our website at vanguard.com or see Contacting Vanguard.

Earning Dividends

You generally will continue earning dividends until the first business day following your redemption or exchange trade date.

Other Redemption Rules You Should Know

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delay payment of the redemption proceeds for up to seven calendar days. By calling us before you attempt to redeem a large dollar amount, you may avoid in-kind or delayed payment of your redemption. Please see Frequent-Trading Limitations for information about Vanguard’s policies to limit frequent trading.

No cancellations. Vanguard will not accept your request to cancel any redemption request once processing has begun. Please be careful when placing a redemption request.

Exchanging Shares

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Vanguard will not accept your request to cancel any exchange request once processing has begun. Please be careful when placing an exchange request.

Call Vanguard before attempting to exchange a large dollar amount. By calling us before you attempt to exchange a large dollar amount, you may avoid delayed or rejected transactions.

Plan participants should consider the following before making an exchange to or from another fund available in your plan:

• Certain investment options, particularly funds made up of company stock or investment contracts, may be subject to unique restrictions.

• Vanguard can accept exchanges only as permitted by your plan. Contact your plan administrator for details on other exchange policies that apply to your plan.

Before making an exchange into another fund, it is important to read that fund’s prospectus. To obtain a copy, please contact Vanguard Participant Services toll-free at 800-523-1188.

Plan Participant Transactions

Plan participant transaction requests (e.g., a contribution, an exchange, or a redemption) must be in good order. Good order means that Vanguard has determined that (1) your transaction request includes complete information and (2) appropriate assets are already in your account or new assets have been received or, if funded via ACH, credited to your account.

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 the Fund. Consult your recordkeeper or plan administrator for more information.

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Your transaction will then be based on the next-determined NAV of the Fund’s Institutional Select Shares. If your transaction request is received in good order before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), you will receive that day’s NAV and trade date. NAVs are calculated only on days that the NYSE is open for trading (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 shall also serve as the conclusion of the trade date. See Share Price.

Frequent-Trading Limitations

For Vanguard Retirement Investment Program pooled plans, the limitations apply to exchanges made online or by telephone.

These frequent-trading limitations do not apply to the following:

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

• Discretionary transactions through Vanguard Personal Advisor Services^®, Vanguard Institutional Advisory Services^®, and Vanguard Digital Advisor™.

• Redemptions of shares to pay fund or account fees.

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• Redemptions of shares to remove excess shareholder contributions to certain types of retirement accounts (including, but not limited to, IRAs 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.

For participants in employer-sponsored defined contribution plans,* the frequent-trading limitations 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 exchange privilege (your ability to purchase shares of a fund using the proceeds from the simultaneous redemption of shares of another fund) may be available to you through your plan. Although we make every effort to maintain the exchange privilege, Vanguard reserves the right to revise or terminate this privilege, limit the amount of an exchange, or reject any exchange, at any time, without notice. Because excessive exchanges can disrupt the management of the Vanguard funds and increase their transaction costs, Vanguard places certain limits on the exchange privilege.

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If you are exchanging out of any Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund), you must wait 30 calendar days before exchanging back into the fund. This policy applies regardless of the dollar amount. Please note that the 30-day clock restarts after every exchange out of the fund.

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

Plans for which Vanguard does not serve as recordkeeper. If Vanguard does not serve as recordkeeper for your plan, your plan’s recordkeeper will establish accounts in Vanguard funds for the benefit of its clients. In such accounts, we cannot always monitor the trading activity of 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 participants’ trading activity with respect to Vanguard funds.

For those Vanguard funds that charge purchase and/or redemption fees, intermediaries that establish accounts in the Vanguard funds will be asked to assess these fees on participant accounts and remit these fees to the funds. The application of purchase and redemption fees and frequent-trading limitations 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 limitations. If a firm other than Vanguard serves as recordkeeper for your plan, please read that firm’s materials carefully to learn of any other rules or fees that may apply.

Accounts Held by Institutions (Other Than Defined Contribution Plans)

Accounts Held by Intermediaries

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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.

Other Rules You Should Know

Prospectus and Shareholder Report Mailings

Vanguard.com

Telephone Transactions

Automatic. When we set up your account, we will automatically enable you to do business with us by telephone, unless you instruct us otherwise in writing.

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

• Account registration and address.

• Fund name and account number, if applicable.

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

Good Order

We 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 types of accounts and transactions. For more information, consult our website at vanguard.com or see Contacting Vanguard.

Vanguard reserves the right, without notice, to revise the requirements for good order.

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Future Trade-Date Requests

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.

Responsibility for Fraud

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.

Uncashed Checks

Dormant Accounts

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.

Investing With Vanguard Through Other Firms

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intermediary can provide you with account information and any required tax forms. You may be required to pay a commission on purchases of mutual fund shares made through a financial intermediary.

Low-Balance Accounts

The Fund reserves the right to convert an investor’s Institutional Select Shares to another share class, as appropriate, if the investor’s fund account balance falls below the account minimum for any reason, including market fluctuation. Any such conversion will be preceded by written notice to the investor.

Right to Change Policies

In addition to the rights expressly stated elsewhere in this prospectus, 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

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Share Classes

Vanguard reserves the right, without notice, to change the eligibility requirements of its share classes, including the types of clients who are eligible to purchase each share class.

Fund and Account Updates

Confirmation Statements

Portfolio Summaries

Tax Information Statements

For many accounts, we (or your intermediary) are required to provide annual tax forms to assist you in preparing your income tax returns. We will send (or provide through our website, whichever you prefer) tax forms for each calendar year early in the following year. For taxable accounts, these forms will generally report the previous year’s dividends, capital gains distributions, and proceeds from the sale of shares. For 401(k) plans and other retirement plans and accounts, these forms will generally report distributions from those accounts during the previous year. Registered users of vanguard.com can also view

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certain forms through our website. Vanguard (or your intermediary) may also provide you with additional tax-related documentation. For more information, consult our website at vanguard.com or see Contacting Vanguard.

Annual and Semiannual Reports

We will send (or provide through our website, whichever you prefer) reports about Vanguard Total Bond Market Index Fund twice a year, in February and August. These reports include overviews of the financial markets and provide the following specific Fund information:

• Performance assessments and comparisons with industry benchmarks.

• Financial statements with listings of Fund holdings.

Portfolio Holdings

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

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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
Vanguard Tele-Account^® 800-662-6273	For automated fund and account information Toll-free, 24 hours a day, 7 days a week
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 888-809-8102	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

Additional Information

	Inception Date	Newspaper Abbreviation	Vanguard Fund Number	CUSIP Number
Total Bond Market Index Fund
Institutional Select Shares	6/24/2016 (Institutional Shares 9/18/1995)	VanTBdMIxInsSel	1884	921937660

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CFA^® is a registered trademark owned by CFA Institute.

Neither Barclays Bank Plc, Barclays Capital Inc., or any affiliate (collectively Barclays) or Bloomberg is the issuer or producer of the Total Bond Market Index Fund and neither Bloomberg nor Barclays has any responsibilities, obligations or duties to investors in the Total Bond Market Index Fund. The Index is licensed for use by The Vanguard Group, Inc. (Vanguard) as the sponsor of the Total Bond Market Index Fund. Bloomberg and Barclays’ only relationship with Vanguard in respect to the Index is the licensing of the Index, which is determined, composed and calculated by BISL, or any successor thereto, without regard to the Issuer or the Total Bond Market Index Fund or the owners of the Total Bond Market Index Fund.

Additionally, Vanguard may for itself execute transaction(s) with Barclays in or relating to the Index in connection with the Total Bond Market Index Fund. Investors acquire the Total Bond Market Index Fund from Vanguard and investors neither acquire any interest in the Index nor enter into any relationship of any kind whatsoever with Bloomberg or Barclays upon making an investment in the Total Bond Market Index Fund. The Total Bond Market Index Fund is not sponsored, endorsed, sold or promoted by Bloomberg or Barclays. Neither Bloomberg nor Barclays makes any representation or warranty, express or implied regarding the advisability of investing in the Total Bond Market Index Fund or the advisability of investing in securities generally or the ability of the Index to track corresponding or relative market performance. Neither Bloomberg nor Barclays has passed on the legality or suitability of the Total Bond Market Index Fund with respect to any person or entity. Neither Bloomberg nor Barclays is responsible for and has not participated in the determination of the timing of, prices at, or quantities of the Total Bond Market Index Fund to be issued. Neither Bloomberg nor Barclays has any obligation to take the needs of the Issuer or the owners of the Total Bond Market Index Fund or any other third party into consideration in determining, composing or calculating the Index. Neither Bloomberg nor Barclays has any obligation or liability in connection with administration, marketing or trading of the Total Bond Market Index Fund.

The licensing agreement between Bloomberg and Barclays is solely for the benefit of Bloomberg and Barclays and not for the benefit of the owners of the Total Bond Market Index Fund, investors or other third parties. In addition, the licensing agreement between Vanguard and Bloomberg is solely for the benefit of Vanguard and Bloomberg and not for the benefit of the owners of the Total Bond Market Index Fund, investors or other third parties.

NEITHER BLOOMBERG NOR BARCLAYS SHALL HAVE ANY LIABILITY TO THE ISSUER, INVESTORS OR TO OTHER THIRD PARTIES FOR THE QUALITY, ACCURACY AND/OR COMPLETENESS OF THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN OR FOR INTERRUPTIONS IN THE DELIVERY OF THE BLOOMBERG BARCLAYS INDEX. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY THE ISSUER, THE INVESTORS OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY EXPRESS OR IMPLIED WARRANTIES, AND EACH HEREBY EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN. BLOOMBERG RESERVES THE RIGHT TO CHANGE THE METHODS OF CALCULATION OR PUBLICATION, OR TO CEASE THE CALCULATION OR PUBLICATION OF THE BLOOMBERG BARCLAYS INDEX, AND NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY MISCALCULATION OF OR ANY INCORRECT, DELAYED OR INTERRUPTED PUBLICATION WITH RESPECT TO THE BLOOMBERG BARCLAYS INDEX. NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY DAMAGES, INCLUDING, WITHOUT LIMITATION, ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY LOST PROFITS AND EVEN IF ADVISED OF THE POSSIBILITY OF SUCH, RESULTING FROM THE USE OF THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN OR WITH RESPECT TO THE TOTAL BOND MARKET INDEX FUND.

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Glossary of Investment Terms

Capital Gains Distributions. Payments to mutual fund shareholders of gains realized on securities that a fund has sold at a profit, minus any realized losses.

Coupon Rate. The interest rate paid by the issuer of a debt security until its maturity. It is expressed as an annual percentage of the face value of the security.

Dividend Distributions. Payments to mutual fund shareholders of income from interest or dividends generated by a fund's investments.

Face Value. The amount to be paid at a bond’s maturity; also known as the par value or principal.

Fixed Income Security. An investment, such as a bond, representing a debt that must be repaid by a specified date, and on which the borrower must pay a fixed, variable, or floating rate of interest.

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Indexing. A low-cost investment strategy in which a mutual fund attempts to track—rather than outperform—a specified market benchmark, or “index.”

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

Mutual Fund. An investment company that pools the money of many people and invests it in a variety of securities in an effort to achieve a specific objective over time.

New York Stock Exchange (NYSE). A stock exchange based in New York City that is open for regular trading on business days, Monday through Friday, from 9:30 a.m. to 4 p.m., Eastern time.

Principal. The face value of a debt instrument or the amount of money put into an investment.

Securities. Stocks, bonds, money market instruments, and other investments.

Total Return. A percentage change, over a specified time period, in a mutual fund's net asset value, assuming the reinvestment of all distributions of dividends and capital gains.

Volatility. The fluctuations in value of a mutual fund or other security. The greater a fund's volatility, the wider the fluctuations in its returns.

Yield. Income (interest or dividends) earned by an investment, expressed as a percentage of the investment’s price.

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Connect with Vanguard^®> vanguard.com

For More Information

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

Annual/Semiannual Reports to Shareholders

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

Statement of Additional Information (SAI)

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

To receive a free copy of the latest annual or semiannual report or the SAI, or to request additional information about the Fund or other Vanguard funds, please visit vanguard.com or contact us as follows:

If you are a client of Vanguard’s Institutional Division:
Telephone: 888-809-8102;
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 Securities and Exchange Commission (SEC)

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

Fund's Investment Company Act file number: 811-04681

I 1884 042020

Vanguard Total Bond Market II Index Fund

Prospectus

April 28, 2020

Investor Shares

Vanguard Total Bond Market II Index Fund Investor Shares (VTBIX)

See the inside front cover for important information about access to your fund’s annual and semiannual shareholder reports.

This prospectus contains financial data for the Fund through the fiscal year ended December 31, 2019.

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.

Important information about access to shareholder reports

Contents

Fund Summary	1
Investing in Index Funds	6
More on the Fund	7
The Fund and Vanguard	18
Investment Advisor	18

Dividends, Capital Gains, and Taxes	19
Share Price	22
Financial Highlights	23
Investing With Vanguard	24
Additional Information	25
Glossary of Investment Terms	28

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Fund Summary

Investment Objective

The Fund seeks to track the performance of a broad, market-weighted bond index.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold Investor Shares of the Fund.

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

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


Management Fees	0.08%
12b-1 Distribution Fee	None
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund’s Investor Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund's shares. This example assumes that the shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you were to redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

1 Year	3 Years	5 Years	10 Years
$9	$29	$51	$115

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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 more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 66% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests by sampling the Index, meaning that it holds a broadly diversified collection of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund's investments will be selected through the sampling process and at least 80% of the Fund's assets will be invested in bonds held in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index. As of December 31, 2019, the dollar-weighted average maturity of the Index was 8.2 years.

Principal Risks

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• Extension risk, which is the chance that during periods of rising interest rates, certain debt securities will be paid off substantially more slowly than originally anticipated, and the value of those securities may fall. This will lengthen the duration or average life of those securities and delay a fund‘s ability to reinvest proceeds at higher interest rates, making a fund more sensitive to changes in interest rates. For funds that invest in mortgage-backed securities, there is a chance that during periods of rising interest rates, homeowners will repay their mortgages at slower rates. Extension risk should be moderate for the Fund.

• Call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. The Fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund’s income. Such redemptions and subsequent reinvestments would also increase the Fund’s portfolio turnover rate. Call risk should be low for the Fund because it invests only a small portion of its assets in callable bonds.

• Liquidity risk, which is the chance that the Fund may not be able to sell a security in a timely manner at a desired price.

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.

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Annual Total Returns

The following bar chart and table 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 the Fund's target index, which has investment characteristics similar to those of 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 or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard Total Bond Market II 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	3.98%	September 30, 2011
Lowest	-3.24%	December 31, 2016

Average Annual Total Returns for Periods Ended December 31, 2019

	1 Year	5 Years	10 Years
Vanguard Total Bond Market II Index Fund Investor Shares
Return Before Taxes	8.62%	2.93%	3.59%
Return After Taxes on Distributions	7.40	1.82	2.47
Return After Taxes on Distributions and Sale of Fund Shares	5.08	1.74	2.31
Bloomberg Barclays U.S. Aggregate Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	8.87%	3.07%	3.78%

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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)

Portfolio Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’s Fixed Income Indexing Americas. He has managed the Fund since 2010.

Purchase and Sale of Fund Shares

Investor Shares are available only to Vanguard funds of funds and certain similar trusts and accounts. There is no minimum investment amount required to open and maintain a Fund account for Investor Shares. The minimum investment amount required to add to an existing Fund account is generally $1.

Tax Information

Payments to Financial Intermediaries

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

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Investing in Index Funds

What Is Indexing?

Index funds typically have the following characteristics:

• Variety of investments. Index funds generally invest in the securities of a variety of companies and industries.

• Relative performance consistency. Because they seek to track market benchmarks, index funds usually do not perform dramatically better or worse than their benchmarks.

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More on the Fund

symbol throughout the prospectus. It is used to mark detailed information about the more significant risks that you would confront as a Fund shareholder. To highlight terms and concepts important to mutual fund investors, we have provided Plain Talk^® explanations along the way. Reading the prospectus will help you decide whether the Fund is the right investment for you. We suggest that you keep this prospectus for future reference.

Share Class Overview

This prospectus offers the Fund's Investor Shares. A separate prospectus offers the Fund’s Institutional Shares, which are generally for investors who invest a minimum of $5 million.

Both share classes offered by the Fund have the same investment objective, strategies, and policies. However, different share classes have different expenses; as a result, their investment returns will differ.

Vanguard Total Bond Market II Index Fund has been established by Vanguard as an investment vehicle for Vanguard funds of funds as well as certain similar trusts and accounts. The Fund is not available to other investors. Vanguard reserves the right to change the availability of the Fund at any time without prior notice to shareholders.

Plain Talk About Fund Expenses

All mutual funds have operating expenses. These expenses, which are deducted from a fund’s gross income, are expressed as a percentage of the net assets of the fund. Assuming that operating expenses remain as stated in the Fees and Expenses section, Vanguard Total Bond Market II Index Fund Investor Shares’ expense ratio would be 0.09%, or $0.90 per $1,000 of average net assets. The average expense ratio for core bond funds in 2019 was 0.69%, or $6.90 per $1,000 of average net assets (derived from data provided by Lipper, a Thomson Reuters Company, which reports on the mutual fund industry).

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Plain Talk About Costs of Investing

The following sections explain the principal investment strategies and policies that the Fund uses in pursuit of its objective. The Fund's board of trustees, which oversees the Fund's management, may change investment strategies or policies in the interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental. Under normal circumstances, the Fund will invest at least 80% of its assets in the bonds that make up its target index. The Fund may change its 80% policy only upon 60 days‘ notice to shareholders.

Market Exposure

The Fund is subject to interest rate risk, which is the chance that bond prices will decline because of rising interest rates. Interest rate risk should be moderate for the Fund because it invests primarily in short- and intermediate-term bonds, whose prices are less sensitive to interest rate changes than are the prices of long-term bonds.

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How Interest Rate Changes Affect the Value of a $1,000 Bond¹

Type of Bond (Maturity)	After a 1% Increase	After a 1% Decrease	After a 2% Increase	After a 2% Decrease
Short-Term (2.5 years)	$977	$1,024	$954	$1,049
Intermediate-Term (10 years)	922	1,086	851	1,180
Long-Term (20 years)	874	1,150	769	1,328

1 Assuming a 4% coupon rate.

These figures are for illustration only; you should not regard them as an indication of future performance of the bond market as a whole or the Fund in particular.

Plain Talk About Bonds and Interest Rates

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Changes in interest rates can affect bond income as well as bond prices.

The Fund is subject to income risk, which is the chance that the Fund’s income will decline because of falling interest rates. A fund's income declines when interest rates fall because the fund then must invest new cash flow and cash from maturing bonds in lower-yielding bonds. Income risk is generally high for short-term bond funds and moderate for intermediate-term bond funds, so investors should expect the Fund‘s monthly income to fluctuate accordingly.

Plain Talk About Bond Maturities

Although falling interest rates tend to strengthen bond prices, they can cause other problems for bond fund investors—bond calls and prepayments.

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Plain Talk About Credit Quality

The Fund is subject to liquidity risk, which is the chance that the Fund may not be able to sell a security in a timely manner at a desired price.

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Security Selection

The number of bonds held by the Fund and the number of bonds in the Fund’s target index were 8,629 and 10,982 respectively, as of December 31, 2019.

Types of bonds. The Fund’s target index is the Bloomberg Barclays U.S. Aggregate Float Adjusted Index. This Index measures the performance of a wide spectrum of public, investment-grade, taxable, fixed income securities 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.

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As of December 31, 2019, the Fund was composed of the following types of bonds:

	U.S. Government/ Agency	Corporate	Mortgage- Backed	International Dollar- Denominated	Other	Total
Total Bond Market II Index Fund	44.6%	28.7%	22.0%	4.1%	0.6%	100%

An explanation of each type of bond follows:

• Corporate bonds are IOUs 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; a company whose credit rating is not strong will have to offer a higher interest rate to obtain buyers for its bonds. For purposes of the preceding table, corporate bonds include securities that are backed by a pool of underlying assets (asset-backed securities) or commercial mortgages (commercial mortgage-backed bonds). The Fund expects to purchase only investment-grade corporate bonds.

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timely payment of principal and interest; those issued by other government agencies or private corporations are not.

The Fund may also invest in conventional mortgage-backed securities—which are packaged by private corporations and are not guaranteed by the U.S. government—and enter into mortgage-dollar-roll transactions. In a mortgage-dollar-roll transaction, a fund sells mortgage-backed securities to a dealer and simultaneously agrees to purchase similar securities in the future at a predetermined price. These transactions simulate an investment in mortgage-backed securities and have the potential to enhance a fund’s returns and reduce its administrative burdens, compared with holding mortgage-backed securities directly. These transactions may increase a fund’s portfolio turnover rate. Mortgage dollar rolls will be used only to the extent that they are consistent with the Fund’s investment objective and risk profile.

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Plain Talk About U.S. Government-Sponsored Entities

Other Investment Policies and Risks

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Cash Management

Methods Used to Meet Redemption Requests

Under normal circumstances, the Fund typically expects to meet redemptions with positive cash flows. When this is not an option, the Fund seeks to maintain its risk exposure by selling a cross section of the Fund’s holdings to meet redemptions, while also factoring in transaction costs. Additionally, since the Fund is only available for limited purchase by certain institutional accounts for which Vanguard or its affiliates has discretionary authority, the Fund’s portfolio

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

Temporary Investment Measures

Frequent Trading or Market-Timing

Investors eligible to purchase shares of the Fund seek to maintain target asset allocations, which may require frequent rebalancing trades. Because the Fund is available only to such investors, the costs imposed by frequent trading are appropriately borne by the investors who cause them. For this reason, the board of trustees of the Fund has determined that it is not necessary to adopt policies and procedures designed to detect and deter frequent trading and market-timing in the Fund’s shares. For information on frequent-trading limits of other Vanguard funds, please see the appropriate fund’s prospectus.

Turnover Rate

Although the Fund generally seeks to invest for the long term, it may sell securities regardless of how long they have been held. Generally, an index fund sells securities in response to redemption requests or to changes in the composition of its target index or in an effort to manage the fund’s duration. The Financial Highlights section of this prospectus shows historical turnover rates for the Fund. A turnover rate of 100%, for example, would mean that the Fund

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had sold and replaced securities valued at 100% of its net assets within a one-year period. Shorter-term bonds will mature or be sold—and need to be replaced—more frequently than longer-term bonds. As a result, shorter-term bond funds tend to have higher turnover rates than longer-term bond funds. In general, the greater the turnover rate, the greater the impact transaction costs will have on a fund’s return. Also, funds with high turnover rates may be more likely to generate capital gains, including short-term capital gains, that must be distributed to shareholders and will be taxable to shareholders investing through a taxable account.

The Fund and Vanguard

Plain Talk About Vanguard’s Unique Corporate Structure

Investment Advisor

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For the fiscal year ended December 31, 2019, the advisory expenses represented an effective annual rate of less than 0.01% of the Fund’s average net assets.

For a discussion of why the board of trustees approved the Fund's investment advisory arrangement, see the most recent semiannual report to shareholders covering the fiscal period ended June 30.

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

Joshua C. Barrickman, CFA, Principal of Vanguard 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, and has managed the Fund since 2010. Education: B.S., Ohio Northern University; M.B.A., Lehigh University.

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

Dividends, Capital Gains, and Taxes

Fund Distributions

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distributed monthly; capital gains distributions, if any, generally occur annually in December. In addition, the Fund may occasionally make a supplemental distribution at some other time during the year.

Plain Talk About Distributions

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 in December—if paid to you by the end of January—are 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 may vary considerably from year to year as a result of the Fund's normal investment activities and cash flows.

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

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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.

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Share Price

Share price, also known as net asset value (NAV), is 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, the Fund reserves the right to treat such day as a business day and calculate NAVs 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. 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. On U.S. holidays or other days when the NYSE is closed, the NAV is not calculated, and the Fund does not sell or redeem shares. However, on those days the value of the 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).

Vanguard fund share prices are published daily on our website at vanguard.com/prices.

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Financial Highlights

Vanguard Total Bond Market II Index Fund Investor Shares

	Year Ended December 31,
For a Share Outstanding Throughout Each Period	2019	2018	2017	2016	2015
Net Asset Value, Beginning of Period	$10.42	$10.72	$10.61	$10.60	$10.84
Investment Operations
Net Investment Income	0.299¹	0.285¹	0.259¹	0.251	0.248
Net Realized and Unrealized Gain (Loss) on Investments	0.590	(0.301)	0.112	0.022	(0.216)
Total from Investment Operations	0.889	(0.016)	0.371	0.273	0.032
Distributions
Dividends from Net Investment Income	(0.299)	(0.284)	(0.259)	(0.252)	(0.248)
Distributions from Realized Capital Gains	—	(0.000)²	(0.002)	(0.011)	(0.024)
Total Distributions	(0.299)	(0.284)	(0.261)	(0.263)	(0.272)
Net Asset Value, End of Period	$11.01	$10.42	$10.72	$10.61	$10.60
Total Return³	8.62%	–0.10%	3.53%	2.55%	0.28%
Ratios/Supplemental Data
Net Assets, End of Period (Millions)	$116,505	$91,653	$89,183	$68,381	$55,392
Ratio of Total Expenses to Average Net Assets	0.09%	0.09%	0.09%	0.09%	0.09%
Ratio of Net Investment Income to Average Net Assets	2.76%	2.74%	2.42%	2.31%	2.30%
Portfolio Turnover Rate⁴	66%	90%	80%	88%	116%

1	Calculated based on average shares outstanding.

2	Distribution was less than $.001 per share.

3	Total returns do not include account service fees that may have applied in the periods shown.

4	Includes 12%, 22%, 26%, 24%, and 46% attributable to mortgage-dollar-roll activity.

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Investing With Vanguard

Purchases, redemptions, and exchanges of shares issued by Vanguard Total Bond Market II Index Fund are conducted by Vanguard or its affiliates on behalf of the participating funds, trusts, and accounts.

Transactions will be based on the next-determined net asset value (NAV) of the Fund’s Investor Shares after Vanguard receives the request (or, in the case of new contributions, the next-determined NAV after Vanguard receives the purchase request). If the request is received before the close of trading on the NYSE (generally 4 p.m., Eastern time), the investor will receive that day’s NAV and trade date. Transaction requests received after that time will receive a trade date of the first business day following the date of receipt. The trade date may vary, depending on the method of payment for the transaction. NAVs are calculated only on days that the NYSE is open for trading (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 shall also serve as the conclusion of the trade date.

If a redemption request is received in good order, Vanguard typically expects that redemption proceeds will be paid by the Fund within one business day of the trade date; however, in certain circumstances, investors may experience a longer settlement period at the time of the transaction.

Portfolio Holdings

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

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Additional Information

	Inception Date	Vanguard Fund Number	CUSIP Number
Total Bond Market II Index Fund
Investor Shares	1/26/2009	635	92203C105

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CFA^® is a registered trademark owned by CFA Institute.

Neither Barclays Bank Plc, Barclays Capital Inc., or any affiliate (collectively Barclays) or Bloomberg is the issuer or producer of the Total Bond Market II Index Fund and neither Bloomberg nor Barclays has any responsibilities, obligations or duties to investors in the Total Bond Market II Index Fund. The Index is licensed for use by The Vanguard Group, Inc. (Vanguard) as the sponsor of the Total Bond Market II Index Fund. Bloomberg and Barclays’ only relationship with Vanguard in respect to the Index is the licensing of the Index, which is determined, composed and calculated by BISL, or any successor thereto, without regard to the Issuer or the Total Bond Market II Index Fund or the owners of the Total Bond Market II Index Fund.

Additionally, Vanguard may for itself execute transaction(s) with Barclays in or relating to the Index in connection with the Total Bond Market II Index Fund. Investors acquire the Total Bond Market II Index Fund from Vanguard and investors neither acquire any interest in the Index nor enter into any relationship of any kind whatsoever with Bloomberg or Barclays upon making an investment in the Total Bond Market II Index Fund. The Total Bond Market II Index Fund is not sponsored, endorsed, sold or promoted by Bloomberg or Barclays. Neither Bloomberg nor Barclays makes any representation or warranty, express or implied regarding the advisability of investing in the Total Bond Market II Index Fund or the advisability of investing in securities generally or the ability of the Index to track corresponding or relative market performance. Neither Bloomberg nor Barclays has passed on the legality or suitability of the Total Bond Market II Index Fund with respect to any person or entity. Neither Bloomberg nor Barclays is responsible for and has not participated in the determination of the timing of, prices at, or quantities of the Total Bond Market II Index Fund to be issued. Neither Bloomberg nor Barclays has any obligation to take the needs of the Issuer or the owners of the Total Bond Market II Index Fund or any other third party into consideration in determining, composing or calculating the Index. Neither Bloomberg nor Barclays has any obligation or liability in connection with administration, marketing or trading of the Total Bond Market II Index Fund.

The licensing agreement between Bloomberg and Barclays is solely for the benefit of Bloomberg and Barclays and not for the benefit of the owners of the Total Bond Market II Index Fund, investors or other third parties. In addition, the licensing agreement between Vanguard and Bloomberg is solely for the benefit of Vanguard and Bloomberg and not for the benefit of the owners of the Total Bond Market II Index Fund, investors or other third parties.

NEITHER BLOOMBERG NOR BARCLAYS SHALL HAVE ANY LIABILITY TO THE ISSUER, INVESTORS OR TO OTHER THIRD PARTIES FOR THE QUALITY, ACCURACY AND/OR COMPLETENESS OF THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN OR FOR INTERRUPTIONS IN THE DELIVERY OF THE BLOOMBERG BARCLAYS INDEX. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY THE ISSUER, THE INVESTORS OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY EXPRESS OR IMPLIED WARRANTIES, AND EACH HEREBY EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN. BLOOMBERG RESERVES THE RIGHT TO CHANGE THE METHODS OF CALCULATION OR PUBLICATION, OR TO CEASE THE CALCULATION OR PUBLICATION OF THE BLOOMBERG BARCLAYS INDEX, AND NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY MISCALCULATION OF OR ANY INCORRECT, DELAYED OR INTERRUPTED PUBLICATION WITH RESPECT TO THE BLOOMBERG BARCLAYS INDEX. NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY DAMAGES, INCLUDING, WITHOUT LIMITATION, ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY LOST PROFITS AND EVEN IF ADVISED OF THE POSSIBILITY OF SUCH, RESULTING FROM THE USE OF THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN OR WITH RESPECT TO THE TOTAL BOND MARKET II INDEX FUND.