Putnam Money Market Fund

Before you invest, you may wish to review the fund’s prospectus, which contains more information about the fund and its risks. You may obtain the prospectus and other information about the fund, including the statement of additional information (SAI) and most recent reports to shareholders, at no cost by visiting putnam.com/funddocuments, calling 1-800-225-1581, or e-mailing Putnam at funddocuments@putnam.com.

The fund’s prospectus and SAI, both dated 1/30/14, are incorporated by reference into this summary prospectus.

Goal

Putnam Money Market Fund seeks as high a rate of current income as Putnam Investment Management, LLC believes is consistent with preservation of capital and maintenance of liquidity.

Fees and expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.

Shareholder fees (fees paid directly from your investment)

Share class	Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)
Class A	NONE	1.00%*
Class B	NONE	5.00%*
Class C	NONE	1.00%*
Class M	NONE	0.15%*
Class R	NONE	NONE
Class T	NONE	NONE*

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Annual fund operating expenses
(expenses you pay each year as a percentage of the value of your investment)

Share class	Management fees	Distribution and service (12b-1) fees	Other expenses	Total annual fund operating expenses
Class A	0.29%	0.00%	0.21%	0.50%
Class B	0.29%	0.50%	0.21%	1.00%
Class C	0.29%	0.50%	0.21%	1.00%
Class M	0.29%	0.15%	0.21%	0.65%
Class R	0.29%	0.50%	0.21%	1.00%
Class T	0.29%	0.25%	0.21%	0.75%

          *  A deferred sales charge on class A, B, C, and T shares may apply to certain redemptions of shares purchased by exchange from another Putnam fund. A deferred sales charge on class M shares may apply to redemptions of shares from certain rollover accounts.

Example

The following hypothetical example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. It assumes that you invest $10,000 in the fund for the time periods indicated and then redeem or hold all your shares at the end of those periods. It assumes a 5% return on your investment each year and that the fund’s operating expenses remain the same. Your actual costs may be higher or lower.

Share class	1 year	3 years	5 years	10 years
Class A	$51	$160	$280	$628
Class B	$102	$318	$552	$1,083
Class C	$102	$318	$552	$1,225
Class M	$66	$208	$362	$810
Class R	$102	$318	$552	$1,225
Class T	$77	$240	$417	$930

Investments, risks, and performance

Investments

We invest mainly in money market instruments that are high quality and have short-term maturities. We invest significantly in certificates of deposit, commercial paper (including asset-backed commercial paper), U.S. government debt and repurchase agreements, corporate obligations and bankers acceptances. We may also invest in U.S. dollar denominated foreign securities of these types. We may consider, among other factors, credit and interest rate risks, as well as general market conditions, when deciding whether to buy or sell investments.

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Risks

The effects of inflation may erode the value of your investment over time. Although the fund seeks to preserve the value of your investment at $1.00 per share, deterioration in the credit quality of issuers whose securities the fund holds or an increase in interest rates may impair the value of your investment, and it is possible to lose money by investing in the fund.

The values of money market investments usually rise and fall in response to changes in interest rates. Interest rate risk is generally lowest for investments with short maturities (a significant part of the fund’s investments). Although the fund only buys high quality investments, investments backed by a letter of credit have the risk that the provider of the letter of credit will not be able to fulfill its obligations to the issuer.

The fund may not achieve its goal, and it is not intended to be a complete investment program. An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance

The performance information below gives some indication of the risks associated with an investment in the fund by showing the fund’s performance year to year and over time. Please remember that past performance is not necessarily an indication of future results. Monthly performance figures for the fund are available at putnam.com.

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Annual total returns for class A shares

Average annual total returns
(for periods ending 12/31/13)

Share class	1 year	5 years	10 years
Class A before taxes	0.01%	0.07%	1.63%
Class B before taxes	–4.99%	–0.37%	1.36%
Class C before taxes	–0.99%	0.04%	1.36%
Class M before taxes	0.01%	0.06%	1.55%
Class R before taxes	0.01%	0.04%	1.36%
Class T before taxes	0.01%	0.05%	1.49%
Lipper Money Market Funds Average (no deduction for taxes)	0.01%	0.05%	1.41%

Class B share performance reflects conversion to class A shares after eight years.

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Your fund’s management

Investment advisor

Putnam Investment Management, LLC

Purchase and sale of fund shares

You can open an account, purchase and/or sell fund shares, or exchange them for shares of another Putnam fund by contacting your financial advisor or by calling Putnam Investor Services at 1-800-225-1581.

When opening an account, you must complete and mail a Putnam account application, along with a check made payable to the fund, to: Putnam Investor Services, P.O. Box 8383, Boston, MA 02266-8383. The minimum initial investment of $500 is currently waived, although Putnam reserves the right to reject initial investments under $500 at its discretion. There is no minimum for subsequent investments. Shares are sold at a net asset value (NAV) of $1.00 per share, without any initial sales charge.

You can sell your shares back to the fund or exchange them for shares of another Putnam fund any day the New York Stock Exchange (NYSE) is open. Shares may be sold or exchanged by mail, by phone, or online at putnam.com. Some restrictions may apply.

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Tax information

Distributions from the fund will be taxed as ordinary income unless you hold the shares through a tax-advantaged arrangement, in which case you will generally be taxed only upon withdrawal of monies from the arrangement.

Financial intermediary compensation

If you purchase the fund through a broker/dealer or other financial intermediary (such as a bank or financial advisor), the fund and its related companies may pay that intermediary for the sale of fund shares and related services. Please bear in mind that these payments may create a conflict of interest by influencing the broker/dealer or other intermediary to recommend the fund over another investment. Ask your advisor or visit your advisor’s website for more information.

Additional information, including current performance, is available at putnam.com/funddocuments, by calling 1-800-225-1581, or by e-mailing Putnam at funddocuments@putnam.com.

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