Total

Fund summary

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 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 examples below. Information about sales charge discounts is available from your financial professional and in the Appendix to the fund’s prospectus.

Shareholder fees (fees paid directly from your investment)

Shareholder Fees - Putnam Money Market Fund	Class A		Class B		Class C		Class R
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	none		none		none		none
Maximum Deferred Sales Charge (as a percentage)	1.00%	[1]	5.00%	[1]	1.00%	[1]	none

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

Annual Fund Operating Expenses - Putnam Money Market Fund		Class A	Class B	Class C	Class R
Management Fees (as a percentage of Assets)		0.28%	0.28%	0.28%	0.28%
Distribution and Service (12b-1) Fees	[1]	none	none	none	none
Other Expenses (as a percentage of Assets):		0.19%	0.19%	0.19%	0.19%
Expenses (as a percentage of Assets)		0.47%	0.47%	0.47%	0.47%

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.

Expense Example - Putnam Money Market Fund - USD ($)	Expense Example, with Redemption, 1 Year		Expense Example, with Redemption, 3 Years		Expense Example, with Redemption, 5 Years		Expense Example, with Redemption, 10 Years		Expense Example, No Redemption, 1 Year	Expense Example, No Redemption, 3 Years	Expense Example, No Redemption, 5 Years	Expense Example, No Redemption, 10 Years
Class A	48		151		263		591
Class B	548	[1]	451	[1]	463	[1]	591	[1]	548	451	463	591
Class C	148		151		263		591		48	151	263	591
Class R	48		151		263		591

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 time deposits. 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 and characteristics of the issuer or counterparty, as well as general market conditions, when deciding whether to buy or sell investments.

Risks

The value of investments in the fund’s portfolio may fall or fail to rise over extended periods of time for a variety of reasons, including general economic, political or financial market conditions, investor sentiment and market perceptions, government actions, geopolitical events or changes, outbreaks of infectious illnesses or other widespread public health issues, and factors related to a specific issuer, geography, industry or sector. These and other factors may lead to increased volatility and reduced liquidity in the fund’s portfolio holdings, may negatively impact the fund’s performance, and may exacerbate other risks to which the fund is subject.

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). Changes in the financial condition of an issuer or counterparty, changes in specific economic or political conditions that affect a particular type of issuer, and changes in general economic or political conditions can increase the risk of default by an issuer or counterparty, which can affect a security’s or instrument’s credit quality or value. To the extent that the fund invests significantly in a particular industry, it runs an increased risk of loss if economic or other developments affecting that industry cause the prices of related money market investments to fall. 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 effects of inflation may erode the value of your investment over time.

Foreign investments, including money market instruments of foreign issuers that are denominated in U.S. dollars, involve certain special risks, such as unfavorable political and legal developments, limited financial information, and economic and financial instability.

There is no guarantee that the investment techniques, analyses, or judgments that we apply in making investment decisions for the fund will produce the intended outcome or that the investments we select for the fund will perform as well as other securities that were not selected for the fund. We, or the fund’s other service providers, may experience disruptions or operating errors that could negatively impact the fund.

The fund may not achieve its goal, and it is not intended to be a complete investment program. 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 the 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.

Best calendar quarter

Dec. 31, 2023

1.29%

Worst calendar quarter

Mar. 31, 2022

none

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.

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.

putnam.com

Annual total returns for class A shares

Average annual total returns (for periods ending 12/31/23)

Average Annual Total Returns - Putnam Money Market Fund	1 Year	5 Years	10 Years
Class A	4.92%	1.71%	1.08%
Class B	(0.08%)	1.33%	1.07%
Class C	3.92%	1.71%	1.07%
Class R	4.92%	1.71%	1.07%

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

The values of money market investments usually rise and fall in response to changes in interest rates.

Foreign investments, including money market instruments of foreign issuers that are denominated in U.S. dollars, involve certain special risks, such as unfavorable political and legal developments, limited financial information, and economic and financial instability.

The fund may impose a fee upon the 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.

You could lose money by investing in the fund.

[1] A deferred sales charge on class A, B and C shares may apply to certain redemptions of shares purchased by exchange from another Putnam fund. The rate of the deferred sales charge for class B shares will be determined based on the time between the original purchase of class B shares from the other Putnam fund(s) and the date of redemption of shares from this fund.

[1] The fund’s Board of Trustees has determined to limit payments under the distribution and service (12b-1) plans in place with respect to class B, class C and class R shares to 0.00% of average net assets.

[1] Reflects assessment of deferred sales charge assuming class B shares were acquired by exchange from one or more other Putnam funds immediately after purchase of shares from such other fund(s).