Vanguard GNMA Fund

Summary Prospectus

May 30, 2013

Investor Shares & Admiral™ Shares

Vanguard GNMA Fund Investor Shares (VFIIX)

Vanguard GNMA Fund Admiral Shares (VFIJX)

The Fund’s statutory Prospectus and Statement of Additional Information dated

May 30, 2013, are incorporated into and made part of this Summary Prospectus

by reference.

Before you invest, you may want to review the Fund’s Prospectus, which

contains more information about the Fund and its risks. You can find

the Fund’s Prospectus and other information about the Fund online at

www.vanguard.com/prospectus. You can also get this information at no

cost by calling 800-662-7447 or by sending an e-mail request to

online@vanguard.com.

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.

Investment Objective

The Fund seeks to provide a moderate level of current income.

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)
	Investor Shares	Admiral 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 (for fund account balances below $10,000)	$20/year	$20/year
Annual Fund Operating Expenses
(Expenses that you pay each year as a percentage of the value of your investment)
	Investor Shares	Admiral Shares
Management Expenses	0.18%	0.09%
12b-1 Distribution Fee	None	None
Other Expenses	0.03%	0.02%
Total Annual Fund Operating Expenses	0.21%	0.11%

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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 invest $10,000 in the Fund’s shares. These examples assume that the Shares provide a return of 5% a year and that total annual fund operating expenses remain as stated in the preceding table. The results apply whether or not you 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
Investor Shares	$22	$68	$118	$268
Admiral Shares	$11	$35	$62	$141

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 130%.

Primary Investment Strategies

The Fund invests at least 80% of its assets in Government National Mortgage Association (GNMA) pass-through certificates, which are fixed income securities representing part ownership in a pool of mortgage loans supported by the full faith and credit of the U.S. government. The balance of the Fund’s assets may be invested in other types of securities such as U.S. Treasury or other U.S. government agency securities, including pass-through certificates, as well as in repurchase agreements collateralized by such securities. Securities issued by most U.S. government agencies, other than the U.S. Treasury and GNMA, are neither guaranteed by the U.S. Treasury nor supported by the full faith and credit of the U.S. government. The Fund’s dollar-weighted average maturity depends on homeowner prepayments of the underlying mortgages. Although the Fund does not observe specific maturity guidelines, the Fund’s dollar-weighted average maturity will normally fall within an intermediate-term range (3 to 10 years).

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Primary Risks

An investment in the Fund could lose money over short or even long periods. You should expect the Fund’s share price and total return to fluctuate within a wide range, like the fluctuations of the overall bond market. The Fund is subject to the following risks, which could affect the Fund’s performance:

• 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. Prepayment risk, which is a type of call risk, is high for the Fund.

• 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.

• Interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates. In addition, when interest rates decline, GNMA prices typically do not rise as much as the prices of comparable bonds. This is because the market tends to discount GNMA prices for prepayment risk when interest rates decline. Interest rate risk should be moderate for the Fund.

• Manager risk, which is the chance that poor security selection will cause the Fund to underperform relevant benchmarks or other funds with a similar investment objective.

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

Annual Total Returns

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 share classes presented compare with those of a relevant market 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 GNMA Fund Investor Shares¹

1 The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2013, was 0.07%.

During the periods shown in the bar chart, the highest return for a calendar quarter was 3.97% (quarter ended December 31, 2008), and the lowest return for a quarter was –1.24% (quarter ended June 30, 2004).

Average Annual Total Returns for Periods Ended December 31, 2012
	1 Year	5 Years	10 Years
Vanguard GNMA Fund Investor Shares
Return Before Taxes	2.35%	5.88%	5.06%
Return After Taxes on Distributions	1.09	4.21	3.35
Return After Taxes on Distributions and Sale of Fund Shares	1.61	4.07	3.32
Vanguard GNMA Fund Admiral Shares
Return Before Taxes	2.45%	5.99%	5.16%
Barclays U.S. GNMA Bond Index
(reflects no deduction for fees, expenses, or taxes)	2.42%	6.03%	5.21%

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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 Investor 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 will 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
Wellington Management Company, LLP

Portfolio Manager

Michael F. Garrett, Senior Vice President and Fixed Income Portfolio Manager of Wellington Management. He has managed the Fund since 2006.

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 following table provides the Fund’s minimum initial and subsequent investment requirements.

Account Minimums	Investor Shares	Admiral Shares
To open and maintain an account	$3,000	$50,000
To add to an existing account	Generally $100 (other than	Generally $100 (other than
	by Automatic Investment	by Automatic Investment
	Plan, which has no	Plan, which has no
	established minimum)	established minimum)

Tax Information

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

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 GNMA Fund Investor Shares—Fund Number 36

Vanguard GNMA Fund Admiral Shares—Fund Number 536

© 2013 The Vanguard Group, Inc. All rights reserved.

Vanguard Marketing Corporation, Distributor.

SP 36 052013