USD ($)

Fund summary

Goal

Putnam Diversified Income Trust seeks as high a level of current income as Putnam Investment Management, LLC believes is consistent with preservation of capital.

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. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in class A shares or $50,000 in class M shares of Putnam funds. More information about these and other discounts is available from your financial professional and in How do I buy fund shares? beginning on page 20 of the fund’s prospectus, in the Appendix to the fund’s prospectus, and in How to buy shares beginning on page II-1 of the fund’s statement of additional information (SAI).

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in class A shares or $50,000 in class M shares of Putnam funds.

$ 50,000

Shareholder fees (fees paid directly from your investment)

Shareholder Fees - Putnam Diversified Income Trust	Class A		Class B		Class C		Class M	Class R	Class R6	Class Y
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	4.00%		none		none		3.25%	none	none	none
Maximum Deferred Sales Charge (as a percentage)	1.00%	[1]	5.00%	[2]	1.00%	[3]	none	none	none	none

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

Annual Fund Operating Expenses - Putnam Diversified Income Trust	Class A	Class B	Class C	Class M	Class R	Class R6	Class Y
Management Fees (as a percentage of Assets)	0.54%	0.54%	0.54%	0.54%	0.54%	0.54%	0.54%
Distribution or Similar (Non 12b-1) Fees	0.25%	1.00%	1.00%	0.50%	0.50%	none	none
Other Expenses (as a percentage of Assets):	0.22%	0.22%	0.22%	0.22%	0.22%	0.12%	0.22%
Expenses (as a percentage of Assets)	1.01%	1.76%	1.76%	1.26%	1.26%	0.66%	0.76%

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, except as indicated, redeem 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 Diversified Income Trust - 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	499	709	936	1,587
Class B	679	854	1,154	1,875	179	554	954	1,875
Class C	279	554	954	1,875	179	554	954	1,875
Class M	449	712	994	1,798
Class R	128	400	692	1,523
Class R6	67	211	368	822
Class Y	78	243	422	942

Portfolio turnover

The fund pays transaction-related costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher turnover rate may indicate higher transaction costs and may result in higher taxes when the fund’s shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or the above example, affect fund performance. The fund’s turnover rate in the most recent fiscal year was 1,163%.

1163.00%

Investments, risks, and performance

Investments

We invest mainly in bonds that are securitized debt instruments (such as mortgage-backed investments) and related derivative instruments, and other obligations of companies and governments worldwide, including bank loans, that are either investment-grade or below-investment-grade in quality (sometimes referred to as “junk bonds”) and have intermediate- to long-term maturities (three years or longer). The fund currently has significant investment exposure to residential and commercial mortgage-backed securities.

We may consider, among other factors, credit, interest rate and prepayment risks, as well as general market conditions, when deciding whether to buy or sell investments. We typically use to a significant extent derivatives, including credit default swaps, interest rate swaps, total return swaps, to-be-announced (TBA) commitments, futures, options and swaptions on mortgage-backed securities and indices, and

certain foreign currency transactions and credit default, total return and interest rate swap contracts for both hedging and non-hedging purposes, including to obtain or adjust exposure to mortgage-backed investments.

Risks

It is important to understand that you can lose money by investing in the fund.

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 or 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 risks associated with bond investments include interest rate risk, which is the risk that the value of the fund’s investments is likely to fall if interest rates rise. Bond investments are also subject to credit risk, which is the risk that the issuer of a bond may default on payment of interest or principal. Bond investments may be more susceptible to downgrades or defaults during economic downturns or other periods of economic stress. Interest rate risk is generally greater for longer-term bonds, and credit risk is generally greater for below-investment-grade bonds (a significant part of the fund’s investments), which can be more sensitive to changes in markets, credit conditions, and interest rates and may be considered speculative.

Mortgage-backed investments, unlike traditional debt investments, are also subject to prepayment risk, which means that they may increase in value less than other bonds when interest rates decline and decline in value more than other bonds when interest rates rise. We may have to invest the proceeds from prepaid investments, including mortgage-backed investments, in other investments with less attractive terms and yields. The fund’s investments in mortgage-backed securities, and in certain other securities and derivatives, may be or become illiquid. The fund currently has significant investment exposure to privately issued residential and commercial mortgage-backed securities and mortgage-backed securities issued or guaranteed by the U.S. government or its agencies or instrumentalities, which may make the fund’s net asset value more susceptible to economic, market, political and other developments affecting the residential and commercial real estate markets and the servicing of mortgage loans secured by real estate properties. During periods of difficult economic conditions, delinquencies and losses on commercial mortgage-backed investments in particular generally increase, including as a result of the effects of those conditions on commercial real estate markets, the ability of commercial tenants to make loan payments, and the ability of a property to attract and retain commercial tenants.

The value of international investments traded in foreign currencies may be adversely impacted by fluctuations in exchange rates. International investments, particularly investments in emerging markets, may carry risks associated with potentially less stable economies or governments (such as the risk of seizure by a foreign government, the imposition of currency or other restrictions, or high levels of inflation), and may be or become illiquid.

Our use of derivatives may increase the risks of investing in the fund by increasing investment exposure (which may be considered leverage) or, in the case of many over-the-counter instruments, because of the potential inability to terminate or sell derivatives positions and the potential failure of the other party to the instrument to meet its obligations. The risk of a party failing to meet its obligations may increase if the fund has significant exposure to that counterparty. The value of derivatives may move in unexpected ways due to unanticipated market movements, the use of leverage, imperfect correlation between the derivative instrument and the reference asset or other factors, especially in unusual market conditions, and volatility in the value of derivatives could adversely impact the fund’s returns, obligations and exposures. Derivatives are also subject to other risks, including liquidity risk (e.g., liquidity demands arising from the requirement to make payments to a derivative counterparty), operational risk (e.g., settlement issues or system failures) and legal risk (e.g., insufficient legal documentation or contract enforceability issues).

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. An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

It is important to understand that you can lose money by investing in the fund.

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. The bar chart does not reflect the impact of sales charges. If it did, performance would be lower. 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.

The bar chart does not reflect the impact of sales charges.

Please remember that past performance is not necessarily an indication of future results.

putnam.com

Annual total returns for class A shares before sales charges

Best calendar quarter

Jun. 30, 2020

7.11%

Worst calendar quarter

Mar. 31, 2020

(13.87%)

Average annual total returns after sales charges (for periods ended 12/31/22)

Average Annual Total Returns - Putnam Diversified Income Trust		1 Year	5 Years	10 Years
Class A		(7.14%)	(0.93%)	1.23%
Class A | After Taxes on Distributions		(9.08%)	(2.64%)	(0.80%)
Class A | After Taxes on Distributions and Sales		(4.22%)	(1.37%)	0.07%
Class B		(8.53%)	(1.18%)	1.03%
Class C		(4.84%)	(0.86%)	1.03%
Class M		(6.69%)	(1.01%)	1.05%
Class R		(3.53%)	(0.35%)	1.40%
Class R6	[1]	(2.92%)	0.22%	1.98%
Class Y		(3.11%)	0.13%	1.89%
ICE BofA U.S. Treasury Bill Index (no deduction for fees, expenses or taxes)		1.33%	1.27%	0.77%
Bloomberg U.S. Aggregate Bond Index (no deduction for fees, expenses or taxes)		(13.01%)	0.02%	1.06%

ICE BofA Indexes: ICE Data Indices, LLC (“ICE BofA”), used with permission. ICE BofA permits use of the ICE BofA indices and related data on an “as is” basis; makes no warranties regarding same; does not guarantee the suitability, quality, accuracy, timeliness, and/or completeness of the ICE BofA indices or any data included in, related to, or derived therefrom; assumes no liability in connection with the use of the foregoing; and does not sponsor, endorse, or recommend Putnam Investments, or any of its products or services.

All Bloomberg indices provided by Bloomberg Index Services Limited.

BLOOMBERG® is a trademark and service mark of Bloomberg Finance L.P. and its affiliates (collectively “Bloomberg”). Bloomberg or Bloomberg’s licensors, own all proprietary rights in the Bloomberg Indices. Neither Bloomberg nor Bloomberg’s licensors approve or endorse this material, or guarantees the accuracy or completeness of any information herein, or makes any warranty, express or implied, as to the results to be obtained therefrom, and to the maximum extent allowed by law, neither shall have any liability or responsibility for injury or damages arising in connection therewith.

After-tax returns reflect the historical highest individual federal marginal income tax rates and do not reflect state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are shown for class A shares only and will vary for other classes. These after-tax returns do not apply if you hold your fund shares through a 401(k) plan, an IRA, or another tax-advantaged arrangement.

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

After-tax returns reflect the historical highest individual federal marginal income tax rates and do not reflect state and local taxes.

Actual after-tax returns depend on an investor’s tax situation and may differ from those shown.

After-tax returns are shown for class A shares only and will vary for other classes.

[1] Applies only to certain redemptions of shares bought with no initial sales charge.

[2] This charge is phased out over six years.

[3] This charge is eliminated after one year.

[1] Performance for class R6 shares prior to their inception (11/1/13) is derived from the historical performance of class Y shares and has not been adjusted for the lower investor servicing fees applicable to class R6 shares; had it, returns would have been higher.