SP 45 Vanguard Municipal Money Market Fund

Vanguard Municipal Money Market Fund

Summary Prospectus

February 28, 2025

Investor Shares

Vanguard Municipal Money Market Fund Investor Shares (VMSXX)

The Fund’s statutory Prospectus and Statement of Additional Information dated February 28, 2025, as may be amended or supplemented, 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 and https://personal.vanguard.com/us/literature/reports/MFs. You can also obtain this information at no cost by calling 800-662-7447 or by sending an email 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 current income that is exempt from federal personal income taxes while maintaining liquidity and a stable share price of $1.

Fees and Expenses

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

Shareholder Fees
(Fees paid directly from your investment)


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

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


Management Fees	0.10 %
12b-1 Distribution Fee	None
Other Expenses	0.01 %
Total Annual Fund Operating Expenses1	0.11 %

The expense information shown in the table has been restated to reflect current fees.

Example

The following example is intended to help you compare the cost of investing in the Fund 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 Fund provides 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
$11	$35	$62	$141

Principal Investment Strategies

The Fund invests in a variety of high-quality, short-term municipal securities. To be considered high quality, a security must be determined by Vanguard to present minimal credit risk based in part on a consideration of maturity, portfolio diversification, portfolio liquidity, and credit quality. The Fund invests in securities with effective maturities of 397 days or less, maintains a dollar-weighted average maturity of 60 days or less, and maintains a dollar-weighted average life of 120 days or less.

Principal Risks

The Fund is designed for investors with a low tolerance for risk; however, the Fund is subject to the following risks, which could affect the Fund’s performance, and the level of risk may very based on market conditions:

• Income risk, which is the chance that the Fund’s income will decline because of falling interest rates. Because the Fund’s income is based on short-term interest rates—which can fluctuate significantly over short periods—income risk is expected to be high. A low or negative interest rate environment will adversely affect the Fund’s return. Low or negative interest rates, depending on their duration and severity, could prevent the Fund from, among other things, providing a positive yield and/or maintaining a stable share price of $1.

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

• Credit risk, which is the chance that the issuer of a security 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 security to decline. Credit risk should be low for the Fund because it invests primarily in securities that are considered to be of high quality.

• 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.

• Tax risk, which is the chance that all or a portion of the tax-exempt income from municipal bonds held by the Fund will be declared taxable, possibly with retroactive effect, because of unfavorable changes in tax laws, adverse interpretations by the Internal Revenue Service or state or local tax authorities, or noncompliant conduct of a bond issuer.

• Structured products risk. The Fund may invest in structured products such as tender option bonds and long-term municipal securities combined with a demand feature (e.g., variable rate demand notes or VRDNs), which may involve risks different from, and possibly greater than, those of investments directly in the underlying securities or assets.

• Regional risk, which is the chance that economic, political, or regulatory occurrences within a certain state may adversely affect the value of securities offered by issuers located within that state. Because the Fund may invest a large portion of its assets in securities located in any one state, the Fund’s performance may be hurt disproportionately by the poor performance of its investments in that area.

You could lose money by investing in the Fund. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. The Fund may impose a fee upon sale of your shares. An investment in the Fund is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s sponsor is not required to reimburse the Fund for losses, and you should not expect that the sponsor will provide financial support to the Fund at any time, including during periods of market stress.

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 has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of a comparative benchmark, which has investment characteristics similar to those of the Fund. Returns for the Tax-Exempt Money Market Funds Average are derived from data provided by Lipper, a Thomson Reuters Company. Keep in mind that the Fund’s past performance does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance.

Annual Total Returns — Vanguard Municipal Money Market 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	0.89 %	December 31, 2023
Lowest	0.00 %	March 31, 2015

Average Annual Total Returns for Periods Ended December 31, 2024

	1 Year	5 Years	10 Years
Vanguard Municipal Money Market Fund Investor Shares	3.29 %	1.61 %	1.18 %
Tax-Exempt Money Market Funds Average	2.89 %	1.40 %	0.96 %

Investment Advisor

The Vanguard Group, Inc. (Vanguard)

Portfolio Manager

John P. Grimes, CFA, Portfolio Manager at Vanguard. He has co-managed the Fund since 2023.

Justin A. Schwartz, CFA, Portfolio Manager at Vanguard and Head of Municipal Index and Money Markets. He has managed the Fund since 2016 (co-managed since 2023).

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 982901, El Paso, TX 79998-2901), or by telephone (800-662-2739). When your trade is processed depends on the day and time Vanguard receives your request in good order and the manner in which it is submitted. Generally, trades placed after the close of business are processed during the next business day. The minimum investment amount required to open and maintain a Fund account for Investor Shares is

$3,000. The minimum investment amount required to add to an existing Fund account is generally $1. Financial intermediaries and Vanguard-advised clients should contact Vanguard for information on special eligibility rules that may apply to them regarding Investor Shares. If you are investing through an intermediary, please contact that firm directly for more information regarding your eligibility. The Fund is a retail money market fund. The Fund is only eligible for purchase within accounts beneficially owned by natural persons. Accounts that are not beneficially owned by natural persons, as determined by the Fund, will be involuntarily redeemed by the Fund or a financial intermediary, in order to implement the Fund’s eligibility as a retail money market fund. Shares held in these accounts will be redeemed using the net asset value as calculated on the day the positions are closed.

Tax Information

The Fund’s distributions may be taxable as ordinary income or capital gains. A majority of the income dividends that you receive from the Fund are expected to be exempt from federal income taxes. However, a portion of the Fund’s distributions may be subject to federal, state, or local income taxes or the federal alternative minimum tax. You should consult your own tax advisor with respect to any particular U.S. or non-U.S. tax consequences of your investment in the Fund.

Payments to Financial Intermediaries

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