TABLE OF CONTENTS
MASSMUTUAL FUNDS​
This Prospectus describes the following Funds:
Fund Name
​ ​
Class I
​ ​
Class R5
​ ​
Service
Class
 ​ ​
Administrative
Class
 ​ ​
Class R4
​ ​
Class A
​ ​
Class R3
​ ​
Class Y
​
MassMutual U.S. Government Money Market Fund
​ ​ ​ ​ ​
MKSXX
​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
MassMutual Inflation-Protected and Income Fund
​ ​
MIPZX
​ ​
MIPSX
​ ​
MIPYX
​ ​
MIPLX
​ ​
MIPRX
​ ​
MPSAX
​ ​
MIPNX
​ ​
MMODX
​
MassMutual Core Bond Fund ​ ​
MCZZX
​ ​
MCBDX
​ ​
MCBYX
​ ​
MCBLX
​ ​
MCZRX
​ ​
MMCBX
​ ​
MCBNX
​ ​
MMNWX
​
MassMutual Diversified Bond Fund ​ ​
MDBZX
​ ​
MDBSX
​ ​
MDBYX
​ ​
MDBLX
​ ​
MDBFX
​ ​
MDVAX
​ ​
MDBRX
​ ​
MMOBX
​
MassMutual Balanced Fund ​ ​
MBBIX
​ ​
MBLDX
​ ​
MBAYX
​ ​
MMBLX
​ ​
MBBRX
​ ​
MMBDX
​ ​
MMBRX
​ ​
MMNVX
​
MassMutual Disciplined Value Fund ​ ​
MPIVX
​ ​
MEPSX
​ ​
DENVX
​ ​
MPILX
​ ​
MPIRX
​ ​
MEPAX
​ ​
MPINX
​ ​
MMOAX
​
MassMutual Main Street Fund ​ ​
MSZIX
​ ​
MMSSX
​ ​
MMSYX
​ ​
MMSLX
​ ​
MSSRX
​ ​
MSSAX
​ ​
MMSNX
​ ​
MMOFX
​
MassMutual Disciplined Growth Fund ​ ​
MPDIX
​ ​
MPGSX
​ ​
DEIGX
​ ​
MPGLX
​ ​
MPDGX
​ ​
MPGAX
​ ​
MPDRX
​ ​
MMNYX
​
MassMutual Small Cap Opportunities Fund
​ ​
MSOOX
​ ​
MSCDX
​ ​
MSVYX
​ ​
MSCLX
​ ​
MOORX
​ ​
DLBMX
​ ​
MCCRX
​ ​
MMOGX
​
MassMutual Global Fund ​ ​
MGFZX
​ ​
MGFSX
​ ​
MGFYX
​ ​
MGFLX
​ ​
MGFRX
​ ​
MGFAX
​ ​
MGFNX
​ ​
MMOCX
​
MassMutual International Equity Fund ​ ​
MIZIX
​ ​
MIEDX
​ ​
MYIEX
​ ​
MIELX
​ ​
MEIRX
​ ​
MMIAX
​ ​
MEERX
​ ​
MMOEX
​
MassMutual Strategic Emerging Markets Fund
​ ​
MPZSX
​ ​
MPSMX
​ ​
MPEYX
​ ​
MPLSX
​ ​
MPRSX
​ ​
MPASX
​ ​
MPZRX
​ ​
MMOHX
 ​
The Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any statement to the contrary is a crime.
PROSPECTUS
February 1, 2023
− 1 −
TABLE OF CONTENTS​
Table Of Contents
​ ​ ​
Page
 ​
About the Funds ​
​ ​ ​ ​ 3 ​ ​
​ ​ ​ ​ 7 ​ ​
​ ​ ​ ​ 15 ​ ​
​ ​ ​ ​ 23 ​ ​
​ ​ ​ ​ 32 ​ ​
​ ​ ​ ​ 42 ​ ​
​ ​ ​ ​ 47 ​ ​
​ ​ ​ ​ 52 ​ ​
​ ​ ​ ​ 57 ​ ​
​ ​ ​ ​ 63 ​ ​
​ ​ ​ ​ 69 ​ ​
​ ​ ​ ​ 76 ​ ​
​ ​ ​
​
 ​ ​
​ ​ ​
​
 ​ ​
​ ​ ​
​
 ​ ​
Management of the Funds ​
​ ​ ​ ​ 106 ​ ​
​ ​ ​ ​ 106 ​ ​
​ ​ ​
​
 ​ ​
​ ​ ​
​
 ​ ​
​ ​ ​
​
 ​ ​
​ ​ ​
​
 ​ ​
​ ​ ​
​
 ​ ​
​ ​ ​
​
 ​ ​
​ ​ ​
​
 ​ ​
​ ​ ​
​
 ​ ​
​ ​ ​
​
 ​ ​
​ ​ ​
​
 ​ ​
​ ​ ​
​
 ​ ​
− 2 −
TABLE OF CONTENTS​
MassMutual U.S. Government Money Market Fund
INVESTMENT OBJECTIVE
This Fund seeks current income consistent with preservation of capital and liquidity.
FEES AND EXPENSES OF THE FUND
This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay brokerage commissions and other fees to financial intermediaries which are not reflected in the tables and examples below.
Shareholder Fees (fees paid directly from your investment)
​ ​ ​
Class R5​
​
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)​ ​ ​
None​
​
Maximum Deferred Sales Charge (Load) (as a % of the lower of the original offering price or redemption proceeds)​ ​ ​
None
​
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your
investment)
​ ​ ​
Class R5​
​
Management Fees​ ​ ​
0.35%
​
Distribution and Service (Rule 12b-1) Fees​ ​ ​
None
​
Other Expenses​ ​ ​
0.19%
 ​
Total Annual Fund Operating Expenses ​ ​
0.54%
 ​
Example
This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. It assumes that you invest $10,000 in Class R5 shares of the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment earns a 5% return each year and that the Fund’s operating expenses are exactly as described in the preceding table. 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​
​
Class R5 ​ ​ ​ $ 55 ​ ​ ​ ​ $ 173 ​ ​ ​ ​ $ 302 ​ ​ ​ ​ $ 677 ​ ​
INVESTMENTS, RISKS, AND PERFORMANCE​
Principal Investment Strategies
The Fund normally invests at least 99.5% of its total assets in cash, U.S. Government securities, and/or repurchase agreements fully collateralized by cash or U.S. Government securities.
In managing the Fund, the Fund’s subadviser, Barings LLC (“Barings”), intends to comply with Rule 2a-7 under the Investment Company Act of 1940, as amended (the “1940 Act”), which sets forth the requirements for money market funds regarding credit quality, diversification, liquidity,
and maturity. The Fund seeks to maintain, but does not guarantee, a stable $1.00 share price.
Under normal circumstances, the Fund invests at least 80% of its net assets in U.S. Government securities and repurchase agreements that are fully collateralized by U.S. Government securities. U.S. Government securities are high-quality securities issued or guaranteed by the U.S. Treasury or by an agency or instrumentality of the U.S. Government. U.S. Government securities may be backed by the full faith and credit of the U.S. Treasury, the right to borrow from the U.S. Treasury, or the agency or instrumentality issuing or guaranteeing the security. Certain issuers of U.S. Government securities, including Fannie Mae, Freddie Mac, and the Federal Home Loan Banks, are sponsored or chartered by Congress but their securities are neither issued nor guaranteed by the U.S. Treasury.
Principal Risks
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. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s sponsor has no legal obligation to provide financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time.
​
− 3 −
TABLE OF CONTENTS
Certain risks relating to instruments and strategies used in the management of the Fund are placed first. The significance of any specific risk to an investment in the Fund will vary over time, depending on the composition of the Fund’s portfolio, market conditions, and other factors. You should read all of the risk information presented below carefully, because any one or more of these risks may result in losses to the Fund.
Money Market Instruments Risk The value of a money market instrument typically will decline during periods of rising interest rates, and can also decline in response to changes in the financial condition of the issuer, borrower, counterparty, or underlying collateral assets, or changes in market, economic, industry, political, regulatory, public health, and other conditions affecting a particular type of security or issuer or fixed income securities generally. Certain events, such as changes in the financial condition of the issuer or borrower, specific market or economic developments, regulatory or government actions, natural disasters, pandemics, terrorist attacks, war, and other geopolitical events can have a dramatic adverse effect on the debt market and the overall liquidity of the market for money market instruments.
U.S. Government Securities Risk Obligations of certain U.S. Government agencies and instrumentalities are not backed by the full faith and credit of the U.S. Government, and there can be no assurance that the U.S. Government would provide financial support to such agencies and instrumentalities.
Repurchase Agreement Risk  These transactions must be fully collateralized, but involve credit risk to a Fund if the other party should default on its obligation and the Fund is delayed or prevented from recovering the collateral.
Credit Risk Credit risk is the risk that an issuer, guarantor, or liquidity provider of a fixed income security held by the Fund may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. The Fund may also be exposed to the credit risk of its counterparty to repurchase agreements, reverse repurchase agreements, swap transactions, and other derivatives transactions, and to the counterparty’s ability or willingness to perform in accordance with the terms of the transaction. The value of such transactions to the Fund will depend on the
willingness and ability of the counterparty to perform its obligations, including among other things the obligation to return collateral or margin to the Fund. If a counterparty becomes bankrupt or otherwise fails to perform its obligations under a derivative contract due to financial difficulties, the Fund may experience significant delays in obtaining any recovery under the derivative contract in a bankruptcy or other reorganization proceeding. The Fund may obtain only a limited recovery or may obtain no recovery in such circumstances.
Inflation Risk The value of assets or income from the Fund’s investments will be less in the future as inflation decreases the value of money. As inflation increases, the value of the Fund’s assets can decline as can the value of the Fund’s distributions. Inflation rates may change frequently and drastically as a result of various factors, including unexpected shifts in the domestic or global economy (or expectations that such policies will change), and the Fund’s investments may not keep pace with inflation, which may result in losses to the Fund’s investors.
LIBOR Risk Certain instruments in which the Fund may invest rely in some fashion upon the London-Interbank Offered Rate (“LIBOR”). On July 27, 2017, the head of the United Kingdom’s Financial Conduct Authority announced a desire to phase out the use of LIBOR by the end of 2021. The administrator of LIBOR ceased publication of most LIBOR settings on a representative basis at the end of 2021 and is expected to cease publication of remaining U.S. dollar LIBOR settings on a representative basis after June 30, 2023. In addition, global regulators have announced that, with limited exceptions, no new LIBOR-based contracts should be entered into after 2021. Actions by regulators have resulted in the establishment of alternative reference rates to LIBOR in most major currencies. Market participants are focused on the transition mechanisms by which the reference rate in existing contracts or instruments may be amended, whether through market wide protocols, fallback contractual provisions, bespoke negotiations or amendments, or otherwise. Markets are developing in response to these new rates, and questions around liquidity in these rates and how to appropriately adjust these rates to eliminate any economic value transfer at the time of transition remain a significant concern for the Fund. Neither the effect of the transition process nor its ultimate success can yet be known. The transition process
​
− 4 −
TABLE OF CONTENTS
may involve, among other things, increased volatility or illiquidity in markets for instruments that rely on LIBOR. In addition, uncertainty and volatility arising from the transition may result in a reduction in the value of certain LIBOR-based instruments held by the Fund or reduce the effectiveness of related transactions such as hedges. Any such effects of the transition away from LIBOR, as well as other unforeseen effects, could result in losses to the Fund.
Liquidity Risk Certain securities may be difficult (or impossible) to sell or certain positions may be difficult to close out at a desirable time and price, and the Fund may be required to hold an illiquid investment that is declining in value, or it may be required to sell certain illiquid investments at a price or time that is not advantageous in order to meet redemptions or other cash needs. Some securities may be subject to restrictions on resale. There can be no assurance that there will be a liquid market for instruments held by the Fund at any time. The Fund may not receive the proceeds from the sale of certain investments for an extended period.
Management Risk The Fund relies on the manager’s investment analysis and its selection of investments to achieve its investment objective. There can be no assurance that the Fund will achieve the intended results and the Fund may incur significant losses.
Market Risk The value of the Fund’s portfolio securities may decline, at times sharply and unpredictably, as a result of unfavorable market-induced changes affecting particular industries, sectors, or issuers. Stock and bond markets can decline significantly in response to issuer, market, economic, industry, political, regulatory, geopolitical, public health, and other conditions, as well as investor perceptions of these conditions. The Fund is subject to risks affecting issuers, such as management performance, financial leverage, industry problems, and reduced demand for goods or services.
Prepayment Risk Prepayment risk is the risk that principal of a debt obligation will be repaid at a faster rate than anticipated. In such a case, a Fund may lose the benefit of a favorable interest rate for the remainder of the term of the security in question, and may only be able to reinvest the amount of the prepayment at a less favorable rate.
Valuation Risk The Fund is subject to the risk of mispricing or improper valuation of its investments, in particular to the extent that its securities are fair valued.
Performance Information
The following bar chart and table provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year for Class R5 shares. The table shows how the Fund’s average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance. The Fund’s name, investment objective, and investment strategy changed on May 1, 2016 when the Fund changed from a money market fund to a government money market fund. Performance results shown were achieved when the Fund could invest in types of securities that it is no longer able to hold. Future performance of the Fund may be lower as a result. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. More up-to-date performance information is available at https://​www.massmutual.com/funds or by calling 1-888-309-3539.
Annual Performance
Class R5 Shares
[MISSING IMAGE: ab4v1sps0t771mpnqp2pv5pli4t9.jpg]
​ Highest Quarter:​ ​ ​
4Q ’22,​
​ ​ ​ ​ 0.77% ​ ​ ​ Lowest Quarter:​ ​ ​ 1Q ’13 thru
3Q ’14; 1Q ’15 thru
4Q ’16; 2Q ’20 thru
1Q ’22, 0.00%		 ​
Average Annual Total Returns
(for the periods ended December 31, 2022)
​ ​ ​ ​ ​ ​ ​ ​
One
Year​
​ ​ ​
Five
Years​
​ ​ ​
Ten
Years​
​
Class R5​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ 1.21 % ​ ​ ​ ​ ​ ​ 0.90 % ​ ​ ​ ​ ​ ​ 0.49 % ​ ​
FTSE 3 Month US T Bill Index
(reflects no deduction for fees,
expenses, or taxes) 		​ ​ ​ ​ ​ 1.50 % ​ ​ ​ ​ ​ ​ 1.25 % ​ ​ ​ ​ ​ ​ 0.74 % ​ ​
​
− 5 −
TABLE OF CONTENTS
MANAGEMENT
Investment Adviser: MML Investment Advisers, LLC (“MML Advisers”)
Subadviser(s): Barings LLC (“Barings”)
Portfolio Manager(s):
Adam Cash is an Associate Director and portfolio manager for Barings’ Global Public Fixed Income Trading and Trading Solutions Group. He has managed the Fund since May 2022.
Scott Simler is a Director and portfolio manager for Barings’ Global Public Fixed Income Trading and Trading Solutions Group. He has managed the Fund since July 2009.
PURCHASE AND SALE OF FUND SHARES
Shares of the Fund are generally available to retirement plans, other institutional investors, and individual retirement accounts. Fund shares are redeemable on any business day by written request, telephone, or internet (available to certain customers).
TAX INFORMATION
The Fund intends to make distributions that may be taxed as ordinary income, qualified dividend income, or capital gains, unless you are an investor eligible for preferential tax treatment.
PAYMENTS TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIES
If you purchase the Fund through a broker-dealer or other financial intermediary, the intermediary may receive a one-time or continuing payments from the Fund, MML Advisers or its affiliates, or others for the sale of Fund shares or continuing shareholder services provided by the intermediary. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary to recommend the Fund over another investment. You should contact your intermediary to obtain more information about the compensation it may receive in connection with your investment.
​
− 6 −
TABLE OF CONTENTS​
MassMutual Inflation-Protected and Income Fund
INVESTMENT OBJECTIVE
This Fund seeks to achieve as high a total rate of real return on an annual basis as is considered consistent with prudent investment risk and the preservation of capital.
FEES AND EXPENSES OF THE FUND
This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay brokerage commissions and other fees to financial intermediaries which are not reflected in the tables and examples below. For Class A shares, you may qualify for sales charge discounts if you invest, or agree to invest in the future, at least $25,000 in MassMutual funds. More information about these and other discounts is available in the section titled Sales Charges by Class beginning on page 114 of the Fund’s Prospectus or from your financial professional.
Shareholder Fees (fees paid directly from your investment)
​ ​ ​
Class I
 ​ ​
Class R5
 ​ ​
Service
Class
 ​ ​
Administrative
Class
 ​ ​
Class R4
 ​ ​
Class A
 ​ ​
Class R3
 ​ ​
Class Y
 ​
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
4.25%
​ ​
None
​ ​
None
​
Maximum Deferred Sales Charge (Load) (as a % of the lower of the original offering price or redemption proceeds)
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your
investment)
​ ​ ​
Class I​
​ ​
Class R5​
​ ​
Service
Class​
​ ​
Admini-
strative Class​
​ ​
Class R4​
​ ​
Class A​
​ ​
Class R3​
​ ​
Class Y
 ​
Management Fees​ ​ ​
0.38%
​ ​
0.38%
​ ​
0.38%
​ ​
0.38%
​ ​
0.38%
​ ​
0.38%
​ ​
0.38%
​ ​
0.38%
​
Distribution and Service (Rule 12b-1) Fees​
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
0.25%
​ ​
0.25%
​ ​
0.50%
​ ​
None
​
Other Expenses​ ​ ​
0.09%
​ ​
0.19%
​ ​
0.29%
​ ​
0.39%
​ ​
0.29%
​ ​
0.39%
​ ​
0.29%
​ ​
0.19%(1)
​
Total Annual Fund Operating Expenses 
 ​ ​
0.47%
 ​ ​
0.57%
 ​ ​
0.67%
 ​ ​
0.77%
 ​ ​
0.92%
 ​ ​
1.02%
 ​ ​
1.17%
 ​ ​
0.57%
 ​
​
(1)
Other Expenses are based on estimated amounts for the current fiscal year of the Fund.
​
Example
This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. It assumes that you invest $10,000 in each share class of the Fund for the time periods indicated and then redeem
all of your shares at the end of those periods. For Class A shares, the example includes the initial sales charge. The example also assumes that your investment earns a 5% return each year and that the Fund’s operating expenses are exactly as described in the preceding table. Although your
​
− 7 −
TABLE OF CONTENTS
actual costs may be higher or lower, based on these assumptions your costs would be:
​ ​ ​
1 Year​
​ ​
3 Years​
​ ​
5 Years​
​ ​
10 Years​
​
Class I ​ ​ ​ $ 48 ​ ​ ​ ​ $ 151 ​ ​ ​ ​ $ 263 ​ ​ ​ ​ $ 591 ​ ​
Class R5 ​ ​ ​ $ 58 ​ ​ ​ ​ $ 183 ​ ​ ​ ​ $ 318 ​ ​ ​ ​ $ 714 ​ ​
Service Class ​ ​ ​ $ 68 ​ ​ ​ ​ $ 214 ​ ​ ​ ​ $ 373 ​ ​ ​ ​ $ 835 ​ ​
Administrative Class
​ ​ ​ $ 79 ​ ​ ​ ​ $ 246 ​ ​ ​ ​ $ 428 ​ ​ ​ ​ $ 954 ​ ​
Class R4 ​ ​ ​ $ 94 ​ ​ ​ ​ $ 293 ​ ​ ​ ​ $ 509 ​ ​ ​ ​ $ 1,131 ​ ​
Class A ​ ​ ​ $ 525 ​ ​ ​ ​ $ 736 ​ ​ ​ ​ $ 964 ​ ​ ​ ​ $ 1,620 ​ ​
Class R3 ​ ​ ​ $ 119 ​ ​ ​ ​ $ 372 ​ ​ ​ ​ $ 644 ​ ​ ​ ​ $ 1,420 ​ ​
Class Y ​ ​ ​ $ 58 ​ ​ ​ ​ $ 183 ​ ​ ​ ​ $ 318 ​ ​ ​ ​ $ 714 ​ ​
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 higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 77% of the average value of its portfolio.
INVESTMENTS, RISKS, AND PERFORMANCE​
Principal Investment Strategies
Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in inflation-indexed bonds and other income-producing securities. Inflation-indexed bonds are instruments indexed or otherwise linked to general measures of inflation because their principal is typically adjusted to reflect general movements of inflation in the country of issue. The Fund may invest in securities of any maturity. The Fund may invest in inflation-indexed bonds issued by the U.S. and non-U.S. governments or their agencies or instrumentalities, by government-sponsored enterprises, or by corporations. The Fund expects to enter into total return swaps based on one or more inflation indexes or on inflation-indexed bonds or other inflation derivatives, as a substitute for purchasing certain inflation-indexed bonds or otherwise to adjust the inflation-sensitivity of the portfolio. Use of total return swaps will create leverage in the Fund.
The Fund may also invest in other income-producing securities of any kind (including, but not limited to, corporate bonds and notes, Rule 144A securities, U.S. and non-U.S.
government and agency or instrumentality bonds, money market instruments, and mortgage-related and asset-backed securities, including collateralized bond and loan obligations). The Fund may enter into repurchase agreement transactions. The Fund may at times have significant exposure to one or more industries or sectors. The Fund may hold a portion of its assets in cash or cash equivalents. The Fund may invest up to 15% of its total assets in securities that are not denominated in U.S. dollars. The Fund may purchase and sell securities on a when-issued, delayed delivery, to-be-announced, or forward commitment basis.
The Fund may invest in (i) securities denominated in currencies of emerging market countries, (ii) fixed income securities or debt instruments issued by emerging market entities or sovereign nations and/or (iii) debt instruments denominated in or based on the currencies, interest rates, or issues of emerging market countries. Emerging market countries are defined to include any country that did not become a member of the Organization for Economic Cooperation and Development (O.E.C.D.) prior to 1975 and Turkey.
The Fund may invest in other investment companies, including investment companies that are advised by the Fund’s investment adviser, subadviser, sub-subadviser, or its affiliates, or by unaffiliated parties.
The Fund generally intends to maintain a dollar-weighted average credit quality of A or better (determined on the basis of the highest credit rating of the Fund’s investments at the time of their purchase or, if unrated, determined to be of comparable quality by the Fund’s subadviser, Barings LLC (“Barings”), or sub-subadviser, Baring International Investment Limited (“BIIL”)). The Fund will invest primarily in assets rated investment grade at the time of purchase (rated Baa3 or higher by Moody’s, BBB- or higher by Standard & Poor’s or the equivalent by any nationally recognized statistical rating organization (“NRSRO”), or, if unrated, determined to be of comparable quality by Barings or BIIL) but not in assets rated below Ba3 by Moody’s, below BB- by Standard & Poor’s and the equivalent by any NRSRO. In the event that a security is downgraded after its purchase by the Fund, the Fund may continue to hold the security if Barings or BIIL considers that doing so would be consistent with the Fund’s investment objective. The Fund invests in a portfolio of securities that Barings or BIIL expects to provide an attractive rate of real return.
​
− 8 −
TABLE OF CONTENTS
Barings or BIIL defines “real return” as the portfolio’s total return (before expenses) less the estimated rate of inflation, measured using the Consumer Price Index for All Urban Consumers (the “CPI-U”).
In addition to the total return swaps and other derivatives referred to above, the Fund may (but is not obligated to) use a wide variety of exchange-traded and over-the-counter derivative transactions, including, but not limited to, total return swaps (for hedging purposes or to adjust various portfolio characteristics, including the duration (interest rate volatility) of the Fund’s portfolio, or as a substitute for direct investments), interest rate swaps (for hedging purposes, to adjust various portfolio characteristics, including the duration (interest rate volatility) of the Fund’s portfolio, or as a substitute for direct investments), credit default swaps (for hedging purposes or as a substitute for direct investments), and futures contracts, foreign currency futures and forward contracts, including derivatives thereof  (for hedging purposes, to adjust various portfolio characteristics, including the duration (interest rate volatility) of the Fund’s portfolio, or as a substitute for direct investments or to gain market exposure). The Fund may also enter into forward commitment transactions. The Fund may invest in common stocks, exchange-traded funds (“ETFs”), or other equity securities and derivatives thereof for hedging purposes or to enhance total return. The use of such techniques may have the effect of creating investment leverage in the Fund.
In selecting investments for the Fund, Barings or BIIL seeks to construct a portfolio of inflation-indexed and other income-producing securities and other financial instruments, including derivatives, designed to meet the real return objective of the Fund. Barings or BIIL may choose to sell securities with deteriorating credit or limited upside potential compared to other securities.
Principal Risks
The following are the Principal Risks of the Fund. The value of your investment in the Fund could go down as well as up. You can lose money by investing in the Fund. References in this section to the Fund’s subadviser may include any sub-subadvisers as applicable. Certain risks relating to instruments and strategies used in the management of the Fund are placed first. The significance of any specific risk to an investment in the Fund will vary over time, depending on the composition of the Fund’s portfolio, market
conditions, and other factors. You should read all of the risk information presented below carefully, because any one or more of these risks may result in losses to the Fund.
Fixed Income Securities Risk The values of fixed income securities typically will decline during periods of rising interest rates, and can also decline in response to changes in the financial condition of the issuer, borrower, counterparty, or underlying collateral assets, or changes in market, economic, industry, political, regulatory, public health, and other conditions affecting a particular type of security or issuer or fixed income securities generally. Certain events, such as market or economic developments, regulatory or government actions, natural disasters, pandemics, terrorist attacks, war, and other geopolitical events can have a dramatic adverse effect on the debt market and the overall liquidity of the market for fixed income securities. During those periods, the Fund may experience high levels of shareholder redemptions, and may have to sell securities at times when the Fund would otherwise not do so, and potentially at unfavorable prices. Certain securities may be difficult to value during such periods. Fixed income securities are subject to interest rate risk (the risk that the value of a fixed income security will fall when interest rates rise), extension risk (the risk that the average life of a security will be extended through a slowing of principal payments), prepayment risk (the risk that a security will be prepaid and the Fund will be required to reinvest at a less favorable rate), duration risk (the risk that longer-term securities may be more sensitive to interest rate changes), inflation risk (the risk that as inflation increases, the present value of the Fund’s fixed income investment typically will decline), and credit risk.
Inflation-Linked Securities Risk Such securities may change in value in response to actual or anticipated changes in inflation rates in a manner unanticipated by the Fund’s portfolio manager or investors generally. Inflation-linked securities are subject to fixed income securities risks. When inflation is low, declining, or negative, the Fund’s performance could lag the performance of more conventional bond funds. Inflation rates may change frequently and drastically as a result of various factors, including unexpected shifts in the domestic or global economy (or expectations that such policies will change), and the Fund’s investments may not keep pace with inflation, which may result in losses to the Fund’s investors.
Credit Risk Credit risk is the risk that an issuer, guarantor, or liquidity provider of a fixed income
​
− 9 −
TABLE OF CONTENTS
security held by the Fund may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. The Fund may also be exposed to the credit risk of its counterparty to repurchase agreements, reverse repurchase agreements, swap transactions, and other derivatives transactions, and to the counterparty’s ability or willingness to perform in accordance with the terms of the transaction. The value of such transactions to the Fund will depend on the willingness and ability of the counterparty to perform its obligations, including among other things the obligation to return collateral or margin to the Fund. If a counterparty becomes bankrupt or otherwise fails to perform its obligations under a derivative contract due to financial difficulties, the Fund may experience significant delays in obtaining any recovery under the derivative contract in a bankruptcy or other reorganization proceeding. The Fund may obtain only a limited recovery or may obtain no recovery in such circumstances.
Derivatives Risk Derivatives can be highly volatile and involve risks different from, and potentially greater than, direct investments, including risks of imperfect correlation between the value of derivatives and underlying assets, counterparty default, potential losses that partially or completely offset gains, and illiquidity. Derivatives can create investment leverage. Losses from derivatives can be substantially greater than the derivatives’ original cost and can sometimes be unlimited. If the value of a derivative does not correlate well with the particular market or asset class the derivative is designed to provide exposure to, the derivative may not have the effect or benefit anticipated. Derivatives can also reduce the opportunity for gains or result in losses by offsetting positive returns in other investments. Many derivatives are traded in the over-the-counter market and not on exchanges.
Foreign Investment Risk; Emerging Markets Risk; Currency Risk Investments in securities of foreign issuers, securities of companies with significant foreign exposure, and foreign currencies can involve additional risks relating to market, industry, political, regulatory, public health, and other conditions. Political, social, diplomatic, and economic developments, U.S. and foreign government action, or threat thereof, such as the imposition of currency or capital blockages,
controls, or tariffs, economic and trade sanctions or embargoes, security trading suspensions, entering or exiting trade or other intergovernmental agreements, or the expropriation or nationalization of assets in a particular country, can cause dramatic declines in certain or all securities with exposure to that country and other countries. In the event of nationalization, expropriation, confiscation, or other government action, intervention, or restriction, the Fund could lose its entire investment in a particular foreign issuer or country. There may be quotas or other limits on the ability of the Fund (or clients of the Fund’s investment adviser or subadviser) to invest or maintain investments in securities of issuers in certain countries. Enforcing legal rights can be more difficult, costly, and limited in certain foreign countries and with respect to certain types of investments, and can be particularly difficult against foreign governments. Because non-U.S. securities are normally denominated and traded in currencies other than the U.S. dollar, the value of the Fund’s assets may be affected favorably or unfavorably by changes in currency exchange rates, exchange control regulations, and restrictions or prohibitions on the repatriation of non-U.S. currencies. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. company than about a U.S. company, and many non-U.S. companies are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the U.S. The securities of some non-U.S. companies, especially those in emerging markets, are less liquid and at times more volatile than securities of comparable U.S. companies. Emerging markets securities are subject to greater risks than securities issued in developed foreign markets, including less liquidity, less stringent investor protection and disclosure standards, less reliable settlement practices, greater price volatility, higher relative rates of inflation, greater political, economic, and social instability, greater custody and operational risks, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments, and greater volatility in currency exchange rates, and are more susceptible to environmental problems. Many emerging market countries are highly reliant on international trade and exports, including the export of commodities. Their economies may be significantly impacted by fluctuations in commodity prices and the global demand for
​
− 10 −
TABLE OF CONTENTS
certain commodities. In addition, pandemics and outbreaks of contagious diseases may exacerbate pre-existing problems in emerging market countries with less established health care systems. Frontier markets, a subset of emerging markets, generally have smaller economies and less mature capital markets than emerging markets. As a result, the risks of investing in emerging market countries are magnified in frontier market countries. Frontier markets are more susceptible to having abrupt changes in currency values, less mature markets and settlement practices, and lower trading volumes that could lead to greater price volatility and illiquidity. Non-U.S. transaction costs, such as brokerage commissions and custody costs, may be higher than in the United States. In addition, foreign markets can react differently to market, economic, industry, political, regulatory, geopolitical, public health, and other conditions than the U.S. market.
Mortgage- and Asset-Backed Securities Risk Investments in mortgage- and asset-backed securities subject the Fund to credit risk, interest rate risk, extension risk, and prepayment risk, among other risks. Mortgage-backed and asset-backed securities not issued by a government agency generally involve greater credit risk than securities issued by government agencies. Payment of principal and interest generally depends on the cash flows generated by the underlying assets and the terms of the security. The types of mortgages (for example, residential or commercial mortgages) underlying securities held by the Fund may differ and be affected differently by market factors. Investments that receive only the interest portion or the principal portion of payments on the underlying assets may be highly volatile. Litigation with respect to the representations and warranties given in connection with the issuance of mortgage-backed securities can be an important consideration in investing in such securities, and the outcome of any such litigation could significantly impact the value of the Fund’s mortgage-backed investments.
Cash Position Risk If the Fund holds a significant portion of its assets in cash or cash equivalents, its investment returns may be adversely affected and the Fund may not achieve its investment objective.
Hedging Risk The Fund’s attempts at hedging and taking long and short positions in currencies may not be successful and could cause the Fund to lose money or fail to get the benefit of a gain on a
hedged position. If expected changes to securities prices, interest rates, currency values, and exchange rates, or the creditworthiness of an issuer are not accurately predicted, the Fund could be in a worse position than if it had not entered into such transactions.
Leveraging Risk Instruments and transactions, including derivatives transactions, that create leverage may cause the value of an investment in the Fund to be more volatile, could result in larger losses than if they were not used, and tend to compound the effects of other risks.
LIBOR Risk Certain instruments in which the Fund may invest rely in some fashion upon the London-Interbank Offered Rate (“LIBOR”). On July 27, 2017, the head of the United Kingdom’s Financial Conduct Authority announced a desire to phase out the use of LIBOR by the end of 2021. The administrator of LIBOR ceased publication of most LIBOR settings on a representative basis at the end of 2021 and is expected to cease publication of remaining U.S. dollar LIBOR settings on a representative basis after June 30, 2023. In addition, global regulators have announced that, with limited exceptions, no new LIBOR-based contracts should be entered into after 2021. Actions by regulators have resulted in the establishment of alternative reference rates to LIBOR in most major currencies. Market participants are focused on the transition mechanisms by which the reference rate in existing contracts or instruments may be amended, whether through market wide protocols, fallback contractual provisions, bespoke negotiations or amendments, or otherwise. Markets are developing in response to these new rates, and questions around liquidity in these rates and how to appropriately adjust these rates to eliminate any economic value transfer at the time of transition remain a significant concern for the Fund. Neither the effect of the transition process nor its ultimate success can yet be known. The transition process may involve, among other things, increased volatility or illiquidity in markets for instruments that rely on LIBOR. In addition, uncertainty and volatility arising from the transition may result in a reduction in the value of certain LIBOR-based instruments held by the Fund or reduce the effectiveness of related transactions such as hedges. Any such effects of the transition away from LIBOR, as well as other unforeseen effects, could result in losses to the Fund.
Liquidity Risk Certain securities may be difficult (or impossible) to sell or certain positions may be
​
− 11 −
TABLE OF CONTENTS
difficult to close out at a desirable time and price, and the Fund may be required to hold an illiquid investment that is declining in value, or it may be required to sell certain illiquid investments at a price or time that is not advantageous in order to meet redemptions or other cash needs. Some securities may be subject to restrictions on resale. There can be no assurance that there will be a liquid market for instruments held by the Fund at any time. The Fund may not receive the proceeds from the sale of certain investments for an extended period.
Management Risk The Fund relies on the manager’s investment analysis and its selection of investments to achieve its investment objective. There can be no assurance that the Fund will achieve the intended results and the Fund may incur significant losses.
Market Risk The value of the Fund’s portfolio securities may decline, at times sharply and unpredictably, as a result of unfavorable market-induced changes affecting particular industries, sectors, or issuers. Stock and bond markets can decline significantly in response to issuer, market, economic, industry, political, regulatory, geopolitical, public health, and other conditions, as well as investor perceptions of these conditions. The Fund is subject to risks affecting issuers, such as management performance, financial leverage, industry problems, and reduced demand for goods or services.
Reinvestment Risk Income from the Fund’s portfolio will decline if and when the Fund invests the proceeds from matured, traded, or called debt obligations at market interest rates that are below the portfolio’s current earnings rate. A decline in income could affect the Fund’s overall return.
Repurchase Agreement Risk  These transactions must be fully collateralized, but involve credit risk to a Fund if the other party should default on its obligation and the Fund is delayed or prevented from recovering the collateral.
Risk of Investment in Other Funds or Pools The Fund is indirectly exposed to all of the risks of the underlying funds, including ETFs, in which it invests, including the risk that the underlying funds will not perform as expected. ETFs are subject to additional risks, including secondary market trading risks and the risk that an ETF’s shares may trade above or below net asset value. The Fund indirectly pays a portion of the expenses incurred by the underlying funds.
Sector Risk The Fund may allocate more of its assets to particular industries or to particular economic, market, or industry sectors than to others. This could increase the volatility of the Fund’s portfolio, and the Fund’s performance may be more susceptible to developments affecting issuers in those industries or sectors than if the Fund invested more broadly.
Sovereign Debt Obligations Risk Investments in debt securities issued by governments or by government agencies and instrumentalities involve the risk that the governmental entities responsible for repayment may be unable or unwilling to pay interest and repay principal when due. Many sovereign debt obligations may be rated below investment grade (“junk” or “high yield” bonds). Any restructuring of a sovereign debt obligation held by the Fund will likely have a significant adverse effect on the value of the obligation. In the event of default of sovereign debt, the Fund may be unable to pursue legal action against the sovereign issuer or to realize on collateral securing the debt.
U.S. Government Securities Risk Obligations of certain U.S. Government agencies and instrumentalities are not backed by the full faith and credit of the U.S. Government, and there can be no assurance that the U.S. Government would provide financial support to such agencies and instrumentalities.
Valuation Risk The Fund is subject to the risk of mispricing or improper valuation of its investments, in particular to the extent that its securities are fair valued.
When-Issued, Delayed Delivery, TBA, and Forward Commitment Transaction Risk These transactions may create leverage and involve a risk of loss if the value of the securities declines prior to settlement.
Performance Information
The following bar chart and table provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year for Class R5 shares. The table shows how the Fund’s average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance. Performance for Class R4 shares of the Fund for periods prior to its inception date (04/01/14) and performance for Class Y shares of the Fund for periods prior to its inception date (02/01/23) is based on the performance of Class R5 shares, adjusted for Class
​
− 12 −
TABLE OF CONTENTS
R4 shares to reflect Class R4 expenses. Performance for Class A shares of the Fund reflects any applicable sales charge. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. More up-to-date performance information is available at https://​www.massmutual.com/funds or by calling 1-888-309-3539.
Annual Performance
Class R5 Shares
[MISSING IMAGE: tf6ff2rpmg2leac3p30109eo5f58.jpg]
​ Highest
Quarter:​ 		​ ​
2Q ’20,​
​ ​ ​ ​ 6.20% ​ ​ ​ Lowest
Quarter:​ 		​ ​
2Q ’13,​
​ ​
–7.15%
 ​
After-tax returns are calculated using the historical highest individual U.S. federal marginal income tax rates and do not reflect the impact of 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 not relevant to investors who hold Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class R5 only. After-tax returns for other classes will vary.
Average Annual Total Returns
(for the periods ended December 31, 2022)
​ ​ ​ ​ ​ ​ ​ ​
One
Year​
​ ​ ​
Five
Years​
​ ​ ​
Ten
Years​
​
Class R5​
​ ​ ​
Return Before
Taxes​
​ ​ ​ ​ ​ -13.42 % ​ ​ ​ ​ ​ ​ 1.80 % ​ ​ ​ ​ ​ ​ 1.00 % ​ ​
​ Return After Taxes on Distributions​ ​ ​ ​ ​ ​ -14.71 % ​ ​ ​ ​ ​ ​ 0.09 % ​ ​ ​ ​ ​ ​ -0.41 % ​ ​
​ Return After Taxes on Distributions and sales of Fund Shares​ ​ ​ ​ ​ ​ -7.93 % ​ ​ ​ ​ ​ ​ 0.72 % ​ ​ ​ ​ ​ ​ 0.20 % ​ ​
Class I​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -13.34 % ​ ​ ​ ​ ​ ​ 1.90 % ​ ​ ​ ​ ​ ​ 1.10 % ​ ​
Service Class​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -13.49 % ​ ​ ​ ​ ​ ​ 1.69 % ​ ​ ​ ​ ​ ​ 0.90 % ​ ​
Administrative
Class​ 		​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -13.59 % ​ ​ ​ ​ ​ ​ 1.59 % ​ ​ ​ ​ ​ ​ 0.80 % ​ ​
Class R4​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -13.62 % ​ ​ ​ ​ ​ ​ 1.46 % ​ ​ ​ ​ ​ ​ 0.67 % ​ ​
​ ​ ​ ​ ​ ​ ​ ​
One
Year​
​ ​ ​
Five
Years​
​ ​ ​
Ten
Years​
​
Class A​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -17.40 % ​ ​ ​ ​ ​ ​ 0.47 % ​ ​ ​ ​ ​ ​ 0.13 % ​ ​
Class R3​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -13.89 % ​ ​ ​ ​ ​ ​ 1.20 % ​ ​ ​ ​ ​ ​ 0.39 % ​ ​
Class Y ​ ​ ​ Return Before
Taxes 		​ ​ ​ ​ ​ -13.42 % ​ ​ ​ ​ ​ ​ 1.80 % ​ ​ ​ ​ ​ ​ 1.00 % ​ ​
Bloomberg U.S. Treasury Inflation
Protected Securities (TIPS) Index
(Series – L) (reflects no deduction
for fees, expenses, or taxes)​ 		​ ​ ​ ​ ​ -11.85 % ​ ​ ​ ​ ​ ​ 2.11 % ​ ​ ​ ​ ​ ​ 1.12 % ​ ​
MANAGEMENT
Investment Adviser: MML Investment Advisers, LLC (“MML Advisers”)
Subadviser(s): Barings LLC (“Barings”)
Sub-subadviser(s):  Baring International Investment Limited (“BIIL”)
Portfolio Manager(s):
Yulia Alekseeva, CFA is a Managing Director, the Head of Securitized Credit Research, and a portfolio manager for Barings’ Investment Grade Fixed Income Group. She has managed the Fund since February 2020.
Douglas Trevallion, II, CFA is a Managing Director, the Head of Global Securitized Credit, and a portfolio manager for Barings’ Investment Grade Fixed Income Group. He has managed the Fund since October 2008.
PURCHASE AND SALE OF FUND SHARES
Shares of the Fund are generally available through distribution channels, such as broker-dealers or financial institutions, and to retirement plans, other institutional investors, and individual retirement accounts. Fund shares are redeemable on any business day by written request, telephone, or internet (available to certain customers).
Purchase Minimums*
 ​
​ ​ ​
Class Y
 ​
Initial Investment ​ ​
$100,000
​
Subsequent Investment ​ ​
$250
​
​
*
The Fund reserves the right to change or waive the investment minimums. For retirement plans, the investment minimum is $250 for each of the initial investment and subsequent investments.
​
TAX INFORMATION
The Fund intends to make distributions that may be taxed as ordinary income, qualified dividend income, or capital gains, unless you are an investor eligible for preferential tax treatment.
​
− 13 −
TABLE OF CONTENTS
PAYMENTS TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIES
If you purchase the Fund through a broker-dealer or other financial intermediary, the intermediary may receive a one-time or continuing payments from the Fund, MML Advisers or its affiliates, or others for the sale of Fund shares or continuing shareholder services provided by the intermediary.
These payments may create a conflict of interest by influencing the broker-dealer or other intermediary to recommend the Fund over another investment. You should contact your intermediary to obtain more information about the compensation it may receive in connection with your investment.
​
− 14 −
TABLE OF CONTENTS​
MassMutual Core Bond Fund
INVESTMENT OBJECTIVE
This Fund seeks to achieve a high total rate of return consistent with prudent investment risk and the preservation of capital by investing primarily in a diversified portfolio of investment grade fixed income securities.
FEES AND EXPENSES OF THE FUND
This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay brokerage commissions and other fees to financial intermediaries which are not reflected in the tables and examples below. For Class A shares, you may qualify for sales charge discounts if you invest, or agree to invest in the future, at least $25,000 in MassMutual funds. More information about these and other discounts is available in the section titled Sales Charges by Class beginning on page 114 of the Fund’s Prospectus or from your financial professional.
Shareholder Fees (fees paid directly from your investment)
​ ​ ​
Class I
 ​ ​
Class R5
 ​ ​
Service
Class
 ​ ​
Administrative
Class
 ​ ​
Class R4
 ​ ​
Class A
 ​ ​
Class R3
 ​ ​
Class Y
 ​
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
4.25%
​ ​
None
​ ​
None
​
Maximum Deferred Sales Charge (Load) (as a % of the lower of the original offering price or redemption proceeds)
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your
investment)
​ ​ ​
Class I​
​ ​
Class R5​
​ ​
Service
Class​
​ ​
Administrative
Class​
​ ​
Class R4​
​ ​
Class A​
​ ​
Class R3​
​ ​
Class Y
 ​
Management Fees​ ​ ​
0.38%
​ ​
0.38%
​ ​
0.38%
​ ​
0.38%
​ ​
0.38%
​ ​
0.38%
​ ​
0.38%
​ ​
0.38%
​
Distribution and Service (Rule 12b-1) Fees​
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
0.25%
​ ​
0.25%
​ ​
0.50%
​ ​
None
​
Other Expenses​ ​ ​
0.04%
​ ​
0.14%
​ ​
0.24%
​ ​
0.34%
​ ​
0.24%
​ ​
0.34%
​ ​
0.24%
​ ​
0.14%(1)
​
Total Annual Fund Operating Expenses 
 ​ ​
0.42%
 ​ ​
0.52%
 ​ ​
0.62%
 ​ ​
0.72%
 ​ ​
0.87%
 ​ ​
0.97%
 ​ ​
1.12%
 ​ ​
0.52%
 ​
​
(1)
Other Expenses are based on estimated amounts for the current fiscal year of the Fund.
​
Example
This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. It assumes that you invest $10,000 in each share class of the Fund for the time periods indicated and then redeem
all of your shares at the end of those periods. For Class A shares, the example includes the initial sales charge. The example also assumes that your investment earns a 5% return each year and that the Fund’s operating expenses are exactly as described in the preceding table. Although your
​
− 15 −
TABLE OF CONTENTS
actual costs may be higher or lower, based on these assumptions your costs would be:
​ ​ ​
1 Year​
​ ​
3 Years​
​ ​
5 Years​
​ ​
10 Years​
​
Class I ​ ​ ​ $ 43 ​ ​ ​ ​ $ 135 ​ ​ ​ ​ $ 235 ​ ​ ​ ​ $ 530 ​ ​
Class R5 ​ ​ ​ $ 53 ​ ​ ​ ​ $ 167 ​ ​ ​ ​ $ 291 ​ ​ ​ ​ $ 653 ​ ​
Service Class ​ ​ ​ $ 63 ​ ​ ​ ​ $ 199 ​ ​ ​ ​ $ 346 ​ ​ ​ ​ $ 774 ​ ​
Administrative Class
​ ​ ​ $ 74 ​ ​ ​ ​ $ 230 ​ ​ ​ ​ $ 401 ​ ​ ​ ​ $ 894 ​ ​
Class R4 ​ ​ ​ $ 89 ​ ​ ​ ​ $ 278 ​ ​ ​ ​ $ 482 ​ ​ ​ ​ $ 1,073 ​ ​
Class A ​ ​ ​ $ 520 ​ ​ ​ ​ $ 721 ​ ​ ​ ​ $ 938 ​ ​ ​ ​ $ 1,564 ​ ​
Class R3 ​ ​ ​ $ 114 ​ ​ ​ ​ $ 356 ​ ​ ​ ​ $ 617 ​ ​ ​ ​ $ 1,363 ​ ​
Class Y ​ ​ ​ $ 53 ​ ​ ​ ​ $ 167 ​ ​ ​ ​ $ 291 ​ ​ ​ ​ $ 653 ​ ​
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 higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 239% of the average value of its portfolio.
INVESTMENTS, RISKS, AND PERFORMANCE​
Principal Investment Strategies
Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in investment grade fixed income securities (rated Baa3 or higher by Moody’s, BBB- or higher by Standard & Poor’s or the equivalent by any nationally recognized statistical rating organization, or, if unrated, determined to be of comparable quality by the Fund’s subadviser, Barings LLC (“Barings”), or sub-subadviser, Baring International Investment Limited (“BIIL”)). These typically include U.S. dollar-denominated corporate obligations, securities issued or guaranteed by the U.S. Government or its agencies or instrumentalities, U.S. and foreign issuer dollar-denominated bonds including, but not limited to, corporate obligations, government and agency issues, private placement bonds, securities subject to resale pursuant to Rule 144A, and mortgage-backed and other asset-backed securities, including collateralized bond and loan obligations. In the event that a security is downgraded after its purchase by the Fund, the Fund may continue to hold the security if Barings or BIIL considers that doing so would be consistent with the Fund’s investment objective.
In pursuing its investment objective, the Fund may (but is not obligated to) use a wide variety of exchange-traded and over-the-counter derivatives, including, but not limited to, futures contracts and forward contracts, including derivatives thereof (for hedging purposes, to adjust various portfolio characteristics, including the duration (interest rate volatility) of the Fund’s portfolio, or as a substitute for direct investments); interest rate swaps (for hedging purposes or as a substitute for direct investments); total return swaps (for hedging purposes or to gain exposure to securities or markets in which it might not be able to invest directly); and credit default swaps (for hedging purposes or as a substitute for direct investments). The Fund may invest in common stocks, exchange-traded funds (“ETFs”), or other equity securities and derivatives thereof for hedging purposes or to enhance total return. Use of derivatives by the Fund may create investment leverage.
The Fund may invest in money market securities, including commercial paper. The Fund may enter into repurchase agreement transactions. The Fund may at times have significant exposure to one or more industries or sectors. The Fund may hold a portion of its assets in cash or cash equivalents. The Fund may purchase and sell securities on a when-issued, delayed delivery, to-be-announced, or forward commitment basis, and may enter into dollar roll or reverse repurchase agreement transactions.
The Fund may invest in other investment companies, including investment companies that are advised by the Fund’s investment adviser, subadviser, sub-subadviser, or its affiliates, or by unaffiliated parties.
Barings or BIIL intends for the Fund’s portfolio dollar-weighted average duration generally to match (within 10%) the average duration of the Bloomberg U.S. Aggregate Bond Index (as of December 31, 2022, the average duration of the Index was 6.17 years). Duration measures the price sensitivity of a bond to changes in interest rates. Duration is the dollar weighted average time to maturity of a bond utilizing the present value of all future cash flows.
Barings or BIIL selects the Fund’s investments based on its analysis of opportunities and risks of various fixed income securities and market sectors. Currently, Barings or BIIL may consider the following factors (which may change over time and in particular cases): the perceived potential for
​
− 16 −
TABLE OF CONTENTS
high income offered by different types of corporate and government obligations (including mortgage-backed and other asset-backed securities); diversification among industries and issuers, credit ratings, and sectors; and the relative values offered by different securities. Barings or BIIL may choose to sell securities with deteriorating credit or limited upside potential compared to other securities.
The Fund expects that it will engage in active and frequent trading and so will typically have a relatively high portfolio turnover rate.
Principal Risks
The following are the Principal Risks of the Fund. The value of your investment in the Fund could go down as well as up. You can lose money by investing in the Fund. References in this section to the Fund’s subadviser may include any sub-subadvisers as applicable. Certain risks relating to instruments and strategies used in the management of the Fund are placed first. The significance of any specific risk to an investment in the Fund will vary over time, depending on the composition of the Fund’s portfolio, market conditions, and other factors. You should read all of the risk information presented below carefully, because any one or more of these risks may result in losses to the Fund.
Fixed Income Securities Risk The values of fixed income securities typically will decline during periods of rising interest rates, and can also decline in response to changes in the financial condition of the issuer, borrower, counterparty, or underlying collateral assets, or changes in market, economic, industry, political, regulatory, public health, and other conditions affecting a particular type of security or issuer or fixed income securities generally. Certain events, such as market or economic developments, regulatory or government actions, natural disasters, pandemics, terrorist attacks, war, and other geopolitical events can have a dramatic adverse effect on the debt market and the overall liquidity of the market for fixed income securities. During those periods, the Fund may experience high levels of shareholder redemptions, and may have to sell securities at times when the Fund would otherwise not do so, and potentially at unfavorable prices. Certain securities may be difficult to value during such periods. Fixed income securities are subject to interest rate risk (the risk that the value of a fixed income security will fall when interest rates rise), extension risk (the risk that the average life of a security will be extended
through a slowing of principal payments), prepayment risk (the risk that a security will be prepaid and the Fund will be required to reinvest at a less favorable rate), duration risk (the risk that longer-term securities may be more sensitive to interest rate changes), inflation risk (the risk that as inflation increases, the present value of the Fund’s fixed income investment typically will decline), and credit risk.
Mortgage- and Asset-Backed Securities Risk Investments in mortgage- and asset-backed securities subject the Fund to credit risk, interest rate risk, extension risk, and prepayment risk, among other risks. Mortgage-backed and asset-backed securities not issued by a government agency generally involve greater credit risk than securities issued by government agencies. Payment of principal and interest generally depends on the cash flows generated by the underlying assets and the terms of the security. The types of mortgages (for example, residential or commercial mortgages) underlying securities held by the Fund may differ and be affected differently by market factors. Investments that receive only the interest portion or the principal portion of payments on the underlying assets may be highly volatile. Litigation with respect to the representations and warranties given in connection with the issuance of mortgage-backed securities can be an important consideration in investing in such securities, and the outcome of any such litigation could significantly impact the value of the Fund’s mortgage-backed investments.
Bank Loans Risk Many of the risks associated with bank loans are similar to the risks of investing in below investment grade debt securities. Changes in the financial condition of the borrower or economic conditions or other circumstances may reduce the capacity of the borrower to make principal and interest payments on such instruments and may lead to defaults. Senior secured bank loans are typically supported by collateral; however the value of the collateral may be insufficient to cover the amount owed to the Fund, or the Fund may be prevented or delayed from realizing on the collateral. Some loans may be unsecured; unsecured loans generally present a greater risk of loss to the Fund if the issuer defaults. If the Fund relies on a third party to administer a loan, the Fund is subject to the risk that the third party will fail to perform its obligations. In addition, if the Fund holds only a participation interest in a loan made by a third party, the Fund’s receipt of payments on the loan
​
− 17 −
TABLE OF CONTENTS
will depend on the third party’s willingness and ability to make those payments to the Fund. The settlement time for certain loans is longer than the settlement time for many other types of investments, and the Fund may not receive the payment for a loan sold by it until well after the sale; that cash would be unavailable for payment of redemption proceeds or for reinvestment. Interests in some bank loans may not be readily marketable and may be subject to restrictions on resale. In some cases, negotiations involved in disposing of indebtedness may require weeks to complete. Consequently, some indebtedness may be difficult or impossible to dispose of readily at what the Fund believes to be a fair price. Some loans may not be considered “securities” for certain purposes under the federal securities laws, and purchasers, such as the Fund, therefore may not be entitled to rely on the anti-fraud protections of the federal securities laws.
Credit Risk Credit risk is the risk that an issuer, guarantor, or liquidity provider of a fixed income security held by the Fund may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. The Fund may also be exposed to the credit risk of its counterparty to repurchase agreements, reverse repurchase agreements, swap transactions, and other derivatives transactions, and to the counterparty’s ability or willingness to perform in accordance with the terms of the transaction. The value of such transactions to the Fund will depend on the willingness and ability of the counterparty to perform its obligations, including among other things the obligation to return collateral or margin to the Fund. If a counterparty becomes bankrupt or otherwise fails to perform its obligations under a derivative contract due to financial difficulties, the Fund may experience significant delays in obtaining any recovery under the derivative contract in a bankruptcy or other reorganization proceeding. The Fund may obtain only a limited recovery or may obtain no recovery in such circumstances.
Derivatives Risk Derivatives can be highly volatile and involve risks different from, and potentially greater than, direct investments, including risks of imperfect correlation between the value of derivatives and underlying assets, counterparty default, potential losses that partially or completely offset gains, and illiquidity. Derivatives can create
investment leverage. Losses from derivatives can be substantially greater than the derivatives’ original cost and can sometimes be unlimited. If the value of a derivative does not correlate well with the particular market or asset class the derivative is designed to provide exposure to, the derivative may not have the effect or benefit anticipated. Derivatives can also reduce the opportunity for gains or result in losses by offsetting positive returns in other investments. Many derivatives are traded in the over-the-counter market and not on exchanges.
Foreign Investment Risk; Emerging Markets Risk; Currency Risk Investments in securities of foreign issuers, securities of companies with significant foreign exposure, and foreign currencies can involve additional risks relating to market, industry, political, regulatory, public health, and other conditions. Political, social, diplomatic, and economic developments, U.S. and foreign government action, or threat thereof, such as the imposition of currency or capital blockages, controls, or tariffs, economic and trade sanctions or embargoes, security trading suspensions, entering or exiting trade or other intergovernmental agreements, or the expropriation or nationalization of assets in a particular country, can cause dramatic declines in certain or all securities with exposure to that country and other countries. In the event of nationalization, expropriation, confiscation, or other government action, intervention, or restriction, the Fund could lose its entire investment in a particular foreign issuer or country. There may be quotas or other limits on the ability of the Fund (or clients of the Fund’s investment adviser or subadviser) to invest or maintain investments in securities of issuers in certain countries. Enforcing legal rights can be more difficult, costly, and limited in certain foreign countries and with respect to certain types of investments, and can be particularly difficult against foreign governments. Because non-U.S. securities are normally denominated and traded in currencies other than the U.S. dollar, the value of the Fund’s assets may be affected favorably or unfavorably by changes in currency exchange rates, exchange control regulations, and restrictions or prohibitions on the repatriation of non-U.S. currencies. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. company than about a U.S. company, and many non-U.S. companies are not subject to accounting, auditing, and financial reporting standards,
​
− 18 −
TABLE OF CONTENTS
regulatory framework and practices comparable to those in the U.S. The securities of some non-U.S. companies, especially those in emerging markets, are less liquid and at times more volatile than securities of comparable U.S. companies. Emerging markets securities are subject to greater risks than securities issued in developed foreign markets, including less liquidity, less stringent investor protection and disclosure standards, less reliable settlement practices, greater price volatility, higher relative rates of inflation, greater political, economic, and social instability, greater custody and operational risks, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments, and greater volatility in currency exchange rates, and are more susceptible to environmental problems. Many emerging market countries are highly reliant on international trade and exports, including the export of commodities. Their economies may be significantly impacted by fluctuations in commodity prices and the global demand for certain commodities. In addition, pandemics and outbreaks of contagious diseases may exacerbate pre-existing problems in emerging market countries with less established health care systems. Frontier markets, a subset of emerging markets, generally have smaller economies and less mature capital markets than emerging markets. As a result, the risks of investing in emerging market countries are magnified in frontier market countries. Frontier markets are more susceptible to having abrupt changes in currency values, less mature markets and settlement practices, and lower trading volumes that could lead to greater price volatility and illiquidity. Non-U.S. transaction costs, such as brokerage commissions and custody costs, may be higher than in the United States. In addition, foreign markets can react differently to market, economic, industry, political, regulatory, geopolitical, public health, and other conditions than the U.S. market.
Cash Position Risk If the Fund holds a significant portion of its assets in cash or cash equivalents, its investment returns may be adversely affected and the Fund may not achieve its investment objective.
Defaulted and Distressed Securities Risk Because the issuer of such securities is in default and is likely to be in distressed financial condition, repayment of defaulted securities and obligations of distressed issuers (including insolvent issuers or issuers in payment or covenant default, in workout or restructuring, or in bankruptcy or
insolvency proceedings) is uncertain. To the extent the Fund is invested in distressed securities, its ability to achieve current income for its shareholders may be diminished.
Dollar Roll and Reverse Repurchase Agreement Transaction Risk These transactions generally create leverage and subject the Fund to the credit risk of the counterparty.
Frequent Trading/Portfolio Turnover Risk Portfolio turnover generally involves some expense to the Fund and may result in the realization of taxable capital gains (including short-term gains). The trading costs and tax effects associated with portfolio turnover may adversely affect the Fund’s performance.
Hedging Risk The Fund’s attempts at hedging and taking long and short positions in currencies may not be successful and could cause the Fund to lose money or fail to get the benefit of a gain on a hedged position. If expected changes to securities prices, interest rates, currency values, and exchange rates, or the creditworthiness of an issuer are not accurately predicted, the Fund could be in a worse position than if it had not entered into such transactions.
Inflation Risk The value of assets or income from the Fund’s investments will be less in the future as inflation decreases the value of money. As inflation increases, the value of the Fund’s assets can decline as can the value of the Fund’s distributions. Inflation rates may change frequently and drastically as a result of various factors, including unexpected shifts in the domestic or global economy (or expectations that such policies will change), and the Fund’s investments may not keep pace with inflation, which may result in losses to the Fund’s investors.
Leveraging Risk Instruments and transactions, including derivatives, dollar roll, and reverse repurchase agreement transactions, that create leverage may cause the value of an investment in the Fund to be more volatile, could result in larger losses than if they were not used, and tend to compound the effects of other risks.
LIBOR Risk Certain instruments in which the Fund may invest rely in some fashion upon the London-Interbank Offered Rate (“LIBOR”). On July 27, 2017, the head of the United Kingdom’s Financial Conduct Authority announced a desire to phase out the use of LIBOR by the end of 2021. The administrator of LIBOR ceased
​
− 19 −
TABLE OF CONTENTS
publication of most LIBOR settings on a representative basis at the end of 2021 and is expected to cease publication of remaining U.S. dollar LIBOR settings on a representative basis after June 30, 2023. In addition, global regulators have announced that, with limited exceptions, no new LIBOR-based contracts should be entered into after 2021. Actions by regulators have resulted in the establishment of alternative reference rates to LIBOR in most major currencies. Market participants are focused on the transition mechanisms by which the reference rate in existing contracts or instruments may be amended, whether through market wide protocols, fallback contractual provisions, bespoke negotiations or amendments, or otherwise. Markets are developing in response to these new rates, and questions around liquidity in these rates and how to appropriately adjust these rates to eliminate any economic value transfer at the time of transition remain a significant concern for the Fund. Neither the effect of the transition process nor its ultimate success can yet be known. The transition process may involve, among other things, increased volatility or illiquidity in markets for instruments that rely on LIBOR. In addition, uncertainty and volatility arising from the transition may result in a reduction in the value of certain LIBOR-based instruments held by the Fund or reduce the effectiveness of related transactions such as hedges. Any such effects of the transition away from LIBOR, as well as other unforeseen effects, could result in losses to the Fund.
Liquidity Risk Certain securities may be difficult (or impossible) to sell or certain positions may be difficult to close out at a desirable time and price, and the Fund may be required to hold an illiquid investment that is declining in value, or it may be required to sell certain illiquid investments at a price or time that is not advantageous in order to meet redemptions or other cash needs. Some securities may be subject to restrictions on resale. There can be no assurance that there will be a liquid market for instruments held by the Fund at any time. The Fund may not receive the proceeds from the sale of certain investments for an extended period.
Management Risk The Fund relies on the manager’s investment analysis and its selection of investments to achieve its investment objective. There can be no assurance that the Fund will achieve the intended results and the Fund may incur significant losses.
Market Risk The value of the Fund’s portfolio securities may decline, at times sharply and
unpredictably, as a result of unfavorable market-induced changes affecting particular industries, sectors, or issuers. Stock and bond markets can decline significantly in response to issuer, market, economic, industry, political, regulatory, geopolitical, public health, and other conditions, as well as investor perceptions of these conditions. The Fund is subject to risks affecting issuers, such as management performance, financial leverage, industry problems, and reduced demand for goods or services.
Reinvestment Risk Income from the Fund’s portfolio will decline if and when the Fund invests the proceeds from matured, traded, or called debt obligations at market interest rates that are below the portfolio’s current earnings rate. A decline in income could affect the Fund’s overall return.
Repurchase Agreement Risk  These transactions must be fully collateralized, but involve credit risk to a Fund if the other party should default on its obligation and the Fund is delayed or prevented from recovering the collateral.
Restricted Securities Risk The Fund may hold securities that are restricted as to resale under the U.S. federal securities laws, such as securities in certain privately held companies. Such securities may be highly illiquid and their values may experience significant volatility. Restricted securities may be difficult to value.
Risk of Investment in Other Funds or Pools The Fund is indirectly exposed to all of the risks of the underlying funds, including ETFs, in which it invests, including the risk that the underlying funds will not perform as expected. ETFs are subject to additional risks, including secondary market trading risks and the risk that an ETF’s shares may trade above or below net asset value. The Fund indirectly pays a portion of the expenses incurred by the underlying funds.
Sector Risk The Fund may allocate more of its assets to particular industries or to particular economic, market, or industry sectors than to others. This could increase the volatility of the Fund’s portfolio, and the Fund’s performance may be more susceptible to developments affecting issuers in those industries or sectors than if the Fund invested more broadly.
U.S. Government Securities Risk Obligations of certain U.S. Government agencies and instrumentalities are not backed by the full faith and credit of the U.S. Government, and there can
​
− 20 −
TABLE OF CONTENTS
be no assurance that the U.S. Government would provide financial support to such agencies and instrumentalities.
Valuation Risk The Fund is subject to the risk of mispricing or improper valuation of its investments, in particular to the extent that its securities are fair valued.
When-Issued, Delayed Delivery, TBA, and Forward Commitment Transaction Risk These transactions may create leverage and involve a risk of loss if the value of the securities declines prior to settlement.
Performance Information
The following bar chart and table provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year for Class R5 shares. The table shows how the Fund’s average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance. Performance for Class R4 shares of the Fund for periods prior to its inception date (04/01/14) and performance for Class Y shares of the Fund for periods prior to its inception date (02/01/23) is based on the performance of Class R5 shares, adjusted for Class R4 shares to reflect Class R4 expenses. Performance for Class A shares of the Fund reflects any applicable sales charge. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. More up-to-date performance information is available at https://​www.massmutual.com/funds or by calling 1-888-309-3539.
Annual Performance
Class R5 Shares
[MISSING IMAGE: ifgd658rh3q75a7g1msh4e5lh78l.jpg]
​ Highest
Quarter:​ 		​ ​
2Q ’20,​
​ ​ ​ ​ 6.65% ​ ​ ​ Lowest
Quarter:​ 		​ ​
2Q ’22,​
​ ​
–6.34%
 ​
After-tax returns are calculated using the historical highest individual U.S. federal marginal income tax rates and do not reflect the impact of 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 not relevant to investors who hold Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After- tax returns are shown for Class R5 only. After-tax returns for other classes will vary.
Average Annual Total Returns
(for the periods ended December 31, 2022)
​ ​ ​ ​ ​ ​ ​ ​
One
Year​
​ ​ ​
Five
Years​
​ ​ ​
Ten
Years​
​
Class R5​
​ ​ ​
Return Before
Taxes​
​ ​ ​ ​ ​ -15.31 % ​ ​ ​ ​ ​ ​ 0.16 % ​ ​ ​ ​ ​ ​ 1.18 % ​ ​
​ Return After Taxes on Distributions​ ​ ​ ​ ​ ​ -16.56 % ​ ​ ​ ​ ​ ​ -1.37 % ​ ​ ​ ​ ​ ​ -0.29 % ​ ​
​ Return After Taxes on Distributions and sales of Fund Shares​ ​ ​ ​ ​ ​ -9.05 % ​ ​ ​ ​ ​ ​ -0.42 % ​ ​ ​ ​ ​ ​ 0.32 % ​ ​
Class I​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -15.19 % ​ ​ ​ ​ ​ ​ 0.26 % ​ ​ ​ ​ ​ ​ 1.29 % ​ ​
Service Class​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -15.39 % ​ ​ ​ ​ ​ ​ 0.05 % ​ ​ ​ ​ ​ ​ 1.08 % ​ ​
Administrative
Class​ 		​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -15.52 % ​ ​ ​ ​ ​ ​ -0.05 % ​ ​ ​ ​ ​ ​ 0.99 % ​ ​
Class R4​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -15.68 % ​ ​ ​ ​ ​ ​ -0.21 % ​ ​ ​ ​ ​ ​ 0.83 % ​ ​
Class A​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -19.24 % ​ ​ ​ ​ ​ ​ -1.15 % ​ ​ ​ ​ ​ ​ 0.30 % ​ ​
Class R3​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -15.80 % ​ ​ ​ ​ ​ ​ -0.42 % ​ ​ ​ ​ ​ ​ 0.57 % ​ ​
Class Y ​ ​ ​ Return Before
Taxes 		​ ​ ​ ​ ​ -15.31 % ​ ​ ​ ​ ​ ​ 0.16 % ​ ​ ​ ​ ​ ​ 1.18 % ​ ​
Bloomberg U.S. Aggregate Bond
Index (reflects no deduction for
fees, expenses, or taxes)​ 		​ ​ ​ ​ ​ -13.01 % ​ ​ ​ ​ ​ ​ 0.02 % ​ ​ ​ ​ ​ ​ 1.06 % ​ ​
MANAGEMENT
Investment Adviser: MML Investment Advisers, LLC (“MML Advisers”)
Subadviser(s): Barings LLC (“Barings”)
Sub-subadviser(s):  Baring International Investment Limited (“BIIL”)
Portfolio Manager(s):
Yulia Alekseeva, CFA is a Managing Director, the Head of Securitized Credit Research, and a portfolio manager for Barings’ Investment Grade Fixed Income Group. She has managed the Fund since December 2020.
Stephen Ehrenberg, CFA is a Managing Director and portfolio manager for Barings’ Investment Grade Fixed Income Group. He has managed the Fund since February 2019.
​
− 21 −
TABLE OF CONTENTS
Charles Sanford is a Managing Director and the Head of, and a portfolio manager for, Barings’ Investment Grade Credit Group. He has managed the Fund since December 2020. He previously managed the Fund from June 2006 to November 2017.
Douglas Trevallion, II, CFA is a Managing Director, the Head of Global Securitized Credit, and a portfolio manager for Barings’ Investment Grade Fixed Income Group. He has managed the Fund since October 2008.
PURCHASE AND SALE OF FUND SHARES
Shares of the Fund are generally available through distribution channels, such as broker-dealers or financial institutions, and to retirement plans, other institutional investors, and individual retirement accounts. Fund shares are redeemable on any business day by written request, telephone, or internet (available to certain customers).
Purchase Minimums*
 ​
​ ​ ​
Class Y
 ​
Initial Investment ​ ​
$100,000
​
Subsequent Investment ​ ​
$250
​
​
*
The Fund reserves the right to change or waive the investment minimums. For retirement plans, the investment minimum is $250 for each of the initial investment and subsequent investments.
​
TAX INFORMATION
The Fund intends to make distributions that may be taxed as ordinary income, qualified dividend income, or capital gains, unless you are an investor eligible for preferential tax treatment.
PAYMENTS TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIES
If you purchase the Fund through a broker-dealer or other financial intermediary, the intermediary may receive a one-time or continuing payments from the Fund, MML Advisers or its affiliates, or others for the sale of Fund shares or continuing shareholder services provided by the intermediary. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary to recommend the Fund over another investment. You should contact your intermediary to obtain more information about the compensation it may receive in connection with your investment.
​
− 22 −
TABLE OF CONTENTS​
MassMutual Diversified Bond Fund
INVESTMENT OBJECTIVE
This Fund seeks a superior total rate of return by investing in fixed income instruments.
FEES AND EXPENSES OF THE FUND
This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay brokerage commissions and other fees to financial intermediaries which are not reflected in the tables and examples below. For Class A shares, you may qualify for sales charge discounts if you invest, or agree to invest in the future, at least $25,000 in MassMutual funds. More information about these and other discounts is available in the section titled Sales Charges by Class beginning on page 114 of the Fund’s Prospectus or from your financial professional.
Shareholder Fees (fees paid directly from your investment)
​ ​ ​
Class I
 ​ ​
Class R5
 ​ ​
Service
Class
 ​ ​
Administrative
Class
 ​ ​
Class R4
 ​ ​
Class A
 ​ ​
Class R3
 ​ ​
Class Y
 ​
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
4.25%
​ ​
None
​ ​
None
​
Maximum Deferred Sales Charge (Load) (as a % of the lower of the original offering price or redemption proceeds)
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your
investment)
​ ​ ​
Class I​
​ ​
Class R5​
​ ​
Service
Class​
​ ​
Admini-
strative Class​
​ ​
Class R4​
​ ​
Class A​
​ ​
Class R3​
​ ​
Class Y
 ​
Management Fees​ ​ ​
0.38%
 ​ ​
0.38%
 ​ ​
0.38%
 ​ ​
0.38%
 ​ ​
0.38%
 ​ ​
0.38%
 ​ ​
0.38%
 ​ ​
0.38%
 ​
Distribution and Service (Rule 12b-1) Fees​
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
0.25%
​ ​
0.25%
​ ​
0.50%
​ ​
None
​
Other Expenses​ ​ ​
0.16%
 ​ ​
0.26%
 ​ ​
0.36%
 ​ ​
0.46%
 ​ ​
0.36%
 ​ ​
0.46%
 ​ ​
0.36%
 ​ ​
0.26%(1)
 ​
Total Annual Fund Operating Expenses 
 ​ ​
0.54%
 ​ ​
0.64%
 ​ ​
0.74%
 ​ ​
0.84%
 ​ ​
0.99%
 ​ ​
1.09%
 ​ ​
1.24%
 ​ ​
0.64%
 ​
​
(1)
Other Expenses are based on estimated amounts for the current fiscal year of the Fund.
​
Example
This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. It assumes that you invest $10,000 in each share class of the Fund for the time periods indicated and then redeem
all of your shares at the end of those periods. For Class A shares, the example includes the initial sales charge. The example also assumes that your investment earns a 5% return each year and that the Fund’s operating expenses are exactly as described in the preceding table. Although your
​
− 23 −
TABLE OF CONTENTS
actual costs may be higher or lower, based on these assumptions your costs would be:
​ ​ ​
1 Year​
​ ​
3 Years​
​ ​
5 Years​
​ ​
10 Years​
​
Class I ​ ​ ​ $ 55 ​ ​ ​ ​ $ 173 ​ ​ ​ ​ $ 302 ​ ​ ​ ​ $ 677 ​ ​
Class R5 ​ ​ ​ $ 65 ​ ​ ​ ​ $ 205 ​ ​ ​ ​ $ 357 ​ ​ ​ ​ $ 798 ​ ​
Service Class ​ ​ ​ $ 76 ​ ​ ​ ​ $ 237 ​ ​ ​ ​ $ 411 ​ ​ ​ ​ $ 918 ​ ​
Administrative Class
​ ​ ​ $ 86 ​ ​ ​ ​ $ 268 ​ ​ ​ ​ $ 466 ​ ​ ​ ​ $ 1,037 ​ ​
Class R4 ​ ​ ​ $ 101 ​ ​ ​ ​ $ 315 ​ ​ ​ ​ $ 547 ​ ​ ​ ​ $ 1,213 ​ ​
Class A ​ ​ ​ $ 531 ​ ​ ​ ​ $ 757 ​ ​ ​ ​ $ 1,000 ​ ​ ​ ​ $ 1,697 ​ ​
Class R3 ​ ​ ​ $ 126 ​ ​ ​ ​ $ 393 ​ ​ ​ ​ $ 681 ​ ​ ​ ​ $ 1,500 ​ ​
Class Y ​ ​ ​ $ 65 ​ ​ ​ ​ $ 205 ​ ​ ​ ​ $ 357 ​ ​ ​ ​ $ 798 ​ ​
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 higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 198% of the average value of its portfolio.
INVESTMENTS, RISKS, AND PERFORMANCE​
Principal Investment Strategies
Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in fixed income securities. These typically include: U.S. dollar-denominated corporate obligations and bank loans, securities issued or guaranteed by the U.S. Government or its agencies or instrumentalities, U.S. and foreign issuer dollar-denominated bonds including, but not limited to, corporate obligations, government and agency issues, private placement bonds, securities subject to resale pursuant to Rule 144A, convertible bonds, and mortgage-backed and other asset-backed securities, including collateralized bond and loan obligations.
The Fund may invest up to 25% of its total assets in securities that are not denominated in U.S. dollars including, but not limited to, corporate obligations, government and agency issues, private placement bonds, convertible bonds, and mortgage-backed and other asset-backed securities, including collateralized bond and loan obligations. The Fund may also invest in non-dollar denominated high yield bonds, including bank loans, and may invest in securities subject to legal
restrictions on resale, some of which may be subject to resale pursuant to Rule 144A.
The Fund may, but will not necessarily, engage in foreign currency futures and forward contracts, including derivatives thereof, for hedging purposes or to gain market exposure. In pursuing its investment objective, the Fund may (but is not obligated to) use a wide variety of exchange-traded and over-the-counter derivatives, including, but not limited to, futures contracts (for hedging purposes, to adjust various portfolio characteristics, including the duration (interest rate volatility) of the Fund’s portfolio, or as a substitute for direct investments); interest rate swaps (for hedging purposes or as a substitute for direct investments); total return swaps (for hedging purposes or to gain exposure to securities or markets in which it might not be able to invest directly); and credit default swaps (for hedging purposes or as a substitute for direct investments). The Fund may invest in common stocks, exchange-traded funds (“ETFs”), or other equity securities and derivatives thereof for hedging purposes or to enhance total return. Use of derivatives by the Fund may create investment leverage.
The Fund may invest in money market securities, including commercial paper. The Fund may enter into repurchase agreement transactions. The Fund may at times have significant exposure to one or more industries or sectors. The Fund may hold a portion of its assets in cash or cash equivalents. The Fund may purchase and sell securities on a when-issued, delayed delivery, to-be-announced, or forward commitment basis, and may enter into dollar roll or reverse repurchase agreement transactions.
The Fund may invest in (i) securities denominated in currencies of emerging market countries, (ii) fixed income securities or debt instruments issued by emerging market entities or sovereign nations and/or (iii) debt instruments denominated in or based on the currencies, interest rates, or issues of emerging market countries. Emerging market countries are defined to include any country that did not become a member of the Organization for Economic Cooperation and Development (O.E.C.D.) prior to 1975 and Turkey.
The Fund may invest in other investment companies, including investment companies that are advised by the Fund’s investment adviser, subadviser, sub-subadviser, or its affiliates, or by unaffiliated parties.
​
− 24 −
TABLE OF CONTENTS
The dollar-weighted average credit quality of the Fund is generally not expected to be less than BBB-/Baa3. The Fund may, however, invest up to 25% of its net assets in below investment grade debt securities (“junk” or “high yield” bonds), including securities in default, and including bank loans, or their unrated equivalent, as determined by the Fund’s subadviser, Barings LLC (“Barings”), or sub-subadviser, Baring International Investment Limited (“BIIL”). Investments in such securities will vary based upon Barings’ or BIIL’s assessment of market conditions and the amount of additional yield offered in relation to the risk of the instruments. In the event that a security is downgraded after its purchase by the Fund, the Fund may continue to hold the security if Barings or BIIL considers that doing so would be consistent with the Fund’s investment objective. Barings or BIIL expects for the Fund’s portfolio dollar-weighted average duration generally to match (plus or minus 2.5 years) the average duration of the Bloomberg U.S. Aggregate Bond Index (as of December 31, 2022, the average duration of the Index was 6.17 years). Duration measures the price sensitivity of a bond to changes in interest rates. Duration is the dollar weighted average time to maturity of a bond utilizing the present value of all future cash flows.
Barings or BIIL selects the Fund’s investments based on its analysis of opportunities and risks of various fixed income securities and market sectors. Currently, Barings or BIIL may consider the following factors (which may change over time and in particular cases): the perceived potential for high income offered by different types of corporate and government obligations (including mortgage-backed and other asset-backed securities); diversification among industries and issuers, credit ratings, and sectors; and the relative values offered by different securities. Barings or BIIL may choose to sell securities with deteriorating credit or limited upside potential compared to other securities.
The Fund expects that it will engage in active and frequent trading and so will typically have a relatively high portfolio turnover rate.
Principal Risks
The following are the Principal Risks of the Fund. The value of your investment in the Fund could go down as well as up. You can lose money by investing in the Fund. References in this section to the Fund’s subadviser may include any sub-subadvisers as applicable. Certain risks relating
to instruments and strategies used in the management of the Fund are placed first. The significance of any specific risk to an investment in the Fund will vary over time, depending on the composition of the Fund’s portfolio, market conditions, and other factors. You should read all of the risk information presented below carefully, because any one or more of these risks may result in losses to the Fund.
Fixed Income Securities Risk The values of fixed income securities typically will decline during periods of rising interest rates, and can also decline in response to changes in the financial condition of the issuer, borrower, counterparty, or underlying collateral assets, or changes in market, economic, industry, political, regulatory, public health, and other conditions affecting a particular type of security or issuer or fixed income securities generally. Certain events, such as market or economic developments, regulatory or government actions, natural disasters, pandemics, terrorist attacks, war, and other geopolitical events can have a dramatic adverse effect on the debt market and the overall liquidity of the market for fixed income securities. During those periods, the Fund may experience high levels of shareholder redemptions, and may have to sell securities at times when the Fund would otherwise not do so, and potentially at unfavorable prices. Certain securities may be difficult to value during such periods. Fixed income securities are subject to interest rate risk (the risk that the value of a fixed income security will fall when interest rates rise), extension risk (the risk that the average life of a security will be extended through a slowing of principal payments), prepayment risk (the risk that a security will be prepaid and the Fund will be required to reinvest at a less favorable rate), duration risk (the risk that longer-term securities may be more sensitive to interest rate changes), inflation risk (the risk that as inflation increases, the present value of the Fund’s fixed income investment typically will decline), and credit risk.
Mortgage- and Asset-Backed Securities Risk Investments in mortgage- and asset-backed securities subject the Fund to credit risk, interest rate risk, extension risk, and prepayment risk, among other risks. Mortgage-backed and asset-backed securities not issued by a government agency generally involve greater credit risk than securities issued by government agencies. Payment of principal and interest generally depends on the cash flows generated by the underlying assets and the terms of the security. The types of
​
− 25 −
TABLE OF CONTENTS
mortgages (for example, residential or commercial mortgages) underlying securities held by the Fund may differ and be affected differently by market factors. Investments that receive only the interest portion or the principal portion of payments on the underlying assets may be highly volatile. Litigation with respect to the representations and warranties given in connection with the issuance of mortgage-backed securities can be an important consideration in investing in such securities, and the outcome of any such litigation could significantly impact the value of the Fund’s mortgage-backed investments.
Bank Loans Risk Many of the risks associated with bank loans are similar to the risks of investing in below investment grade debt securities. Changes in the financial condition of the borrower or economic conditions or other circumstances may reduce the capacity of the borrower to make principal and interest payments on such instruments and may lead to defaults. Senior secured bank loans are typically supported by collateral; however the value of the collateral may be insufficient to cover the amount owed to the Fund, or the Fund may be prevented or delayed from realizing on the collateral. Some loans may be unsecured; unsecured loans generally present a greater risk of loss to the Fund if the issuer defaults. If the Fund relies on a third party to administer a loan, the Fund is subject to the risk that the third party will fail to perform its obligations. In addition, if the Fund holds only a participation interest in a loan made by a third party, the Fund’s receipt of payments on the loan will depend on the third party’s willingness and ability to make those payments to the Fund. The settlement time for certain loans is longer than the settlement time for many other types of investments, and the Fund may not receive the payment for a loan sold by it until well after the sale; that cash would be unavailable for payment of redemption proceeds or for reinvestment. Interests in some bank loans may not be readily marketable and may be subject to restrictions on resale. In some cases, negotiations involved in disposing of indebtedness may require weeks to complete. Consequently, some indebtedness may be difficult or impossible to dispose of readily at what the Fund believes to be a fair price. Some loans may not be considered “securities” for certain purposes under the federal securities laws, and purchasers, such as the Fund, therefore may not be entitled to rely on the anti-fraud protections of the federal securities laws.
Below Investment Grade Debt Securities Risk Below investment grade debt securities, commonly known
as “junk” or “high yield” bonds, have speculative characteristics and involve greater volatility of price and yield, greater risk of loss of principal and interest, and generally reflect a greater possibility of an adverse change in financial condition that could affect an issuer’s ability to honor its obligations.
Credit Risk Credit risk is the risk that an issuer, guarantor, or liquidity provider of a fixed income security held by the Fund may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. The Fund may also be exposed to the credit risk of its counterparty to repurchase agreements, reverse repurchase agreements, swap transactions, and other derivatives transactions, and to the counterparty’s ability or willingness to perform in accordance with the terms of the transaction. The value of such transactions to the Fund will depend on the willingness and ability of the counterparty to perform its obligations, including among other things the obligation to return collateral or margin to the Fund. If a counterparty becomes bankrupt or otherwise fails to perform its obligations under a derivative contract due to financial difficulties, the Fund may experience significant delays in obtaining any recovery under the derivative contract in a bankruptcy or other reorganization proceeding. The Fund may obtain only a limited recovery or may obtain no recovery in such circumstances.
Derivatives Risk Derivatives can be highly volatile and involve risks different from, and potentially greater than, direct investments, including risks of imperfect correlation between the value of derivatives and underlying assets, counterparty default, potential losses that partially or completely offset gains, and illiquidity. Derivatives can create investment leverage. Losses from derivatives can be substantially greater than the derivatives’ original cost and can sometimes be unlimited. If the value of a derivative does not correlate well with the particular market or asset class the derivative is designed to provide exposure to, the derivative may not have the effect or benefit anticipated. Derivatives can also reduce the opportunity for gains or result in losses by offsetting positive returns in other investments. Many derivatives are traded in the over-the-counter market and not on exchanges.
​
− 26 −
TABLE OF CONTENTS
Foreign Investment Risk; Emerging Markets Risk; Currency Risk Investments in securities of foreign issuers, securities of companies with significant foreign exposure, and foreign currencies can involve additional risks relating to market, industry, political, regulatory, public health, and other conditions. Political, social, diplomatic, and economic developments, U.S. and foreign government action, or threat thereof, such as the imposition of currency or capital blockages, controls, or tariffs, economic and trade sanctions or embargoes, security trading suspensions, entering or exiting trade or other intergovernmental agreements, or the expropriation or nationalization of assets in a particular country, can cause dramatic declines in certain or all securities with exposure to that country and other countries. In the event of nationalization, expropriation, confiscation, or other government action, intervention, or restriction, the Fund could lose its entire investment in a particular foreign issuer or country. There may be quotas or other limits on the ability of the Fund (or clients of the Fund’s investment adviser or subadviser) to invest or maintain investments in securities of issuers in certain countries. Enforcing legal rights can be more difficult, costly, and limited in certain foreign countries and with respect to certain types of investments, and can be particularly difficult against foreign governments. Because non-U.S. securities are normally denominated and traded in currencies other than the U.S. dollar, the value of the Fund’s assets may be affected favorably or unfavorably by changes in currency exchange rates, exchange control regulations, and restrictions or prohibitions on the repatriation of non-U.S. currencies. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. company than about a U.S. company, and many non-U.S. companies are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the U.S. The securities of some non-U.S. companies, especially those in emerging markets, are less liquid and at times more volatile than securities of comparable U.S. companies. Emerging markets securities are subject to greater risks than securities issued in developed foreign markets, including less liquidity, less stringent investor protection and disclosure standards, less reliable settlement practices, greater price volatility, higher relative rates of inflation, greater political, economic, and social instability, greater custody
and operational risks, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments, and greater volatility in currency exchange rates, and are more susceptible to environmental problems. Many emerging market countries are highly reliant on international trade and exports, including the export of commodities. Their economies may be significantly impacted by fluctuations in commodity prices and the global demand for certain commodities. In addition, pandemics and outbreaks of contagious diseases may exacerbate pre-existing problems in emerging market countries with less established health care systems. Frontier markets, a subset of emerging markets, generally have smaller economies and less mature capital markets than emerging markets. As a result, the risks of investing in emerging market countries are magnified in frontier market countries. Frontier markets are more susceptible to having abrupt changes in currency values, less mature markets and settlement practices, and lower trading volumes that could lead to greater price volatility and illiquidity. Non-U.S. transaction costs, such as brokerage commissions and custody costs, may be higher than in the United States. In addition, foreign markets can react differently to market, economic, industry, political, regulatory, geopolitical, public health, and other conditions than the U.S. market.
Cash Position Risk If the Fund holds a significant portion of its assets in cash or cash equivalents, its investment returns may be adversely affected and the Fund may not achieve its investment objective.
Convertible Securities Risk Convertible securities are subject to the risks of both debt instruments and equity securities. The price of a convertible security may change in response to changes in price of the underlying equity security, the credit quality of the issuer, and interest rates. In general, the values of convertible securities tend to decline as interest rates rise and to rise when interest rates fall. A convertible security generally has less potential for gain or loss than the underlying equity security.
Defaulted and Distressed Securities Risk Because the issuer of such securities is in default and is likely to be in distressed financial condition, repayment of defaulted securities and obligations of distressed issuers (including insolvent issuers or issuers in payment or covenant default, in workout or restructuring, or in bankruptcy or insolvency proceedings) is uncertain. To the extent
​
− 27 −
TABLE OF CONTENTS
the Fund is invested in distressed securities, its ability to achieve current income for its shareholders may be diminished.
Dollar Roll and Reverse Repurchase Agreement Transaction Risk These transactions generally create leverage and subject the Fund to the credit risk of the counterparty.
Frequent Trading/Portfolio Turnover Risk Portfolio turnover generally involves some expense to the Fund and may result in the realization of taxable capital gains (including short-term gains). The trading costs and tax effects associated with portfolio turnover may adversely affect the Fund’s performance.
Hedging Risk The Fund’s attempts at hedging and taking long and short positions in currencies may not be successful and could cause the Fund to lose money or fail to get the benefit of a gain on a hedged position. If expected changes to securities prices, interest rates, currency values, and exchange rates, or the creditworthiness of an issuer are not accurately predicted, the Fund could be in a worse position than if it had not entered into such transactions.
Inflation Risk The value of assets or income from the Fund’s investments will be less in the future as inflation decreases the value of money. As inflation increases, the value of the Fund’s assets can decline as can the value of the Fund’s distributions. Inflation rates may change frequently and drastically as a result of various factors, including unexpected shifts in the domestic or global economy (or expectations that such policies will change), and the Fund’s investments may not keep pace with inflation, which may result in losses to the Fund’s investors.
Leveraging Risk Instruments and transactions, including derivatives, dollar roll, and reverse repurchase agreement transactions, that create leverage may cause the value of an investment in the Fund to be more volatile, could result in larger losses than if they were not used, and tend to compound the effects of other risks.
LIBOR Risk Certain instruments in which the Fund may invest rely in some fashion upon the London-Interbank Offered Rate (“LIBOR”). On July 27, 2017, the head of the United Kingdom’s Financial Conduct Authority announced a desire to phase out the use of LIBOR by the end of 2021. The administrator of LIBOR ceased publication of most LIBOR settings on a
representative basis at the end of 2021 and is expected to cease publication of remaining U.S. dollar LIBOR settings on a representative basis after June 30, 2023. In addition, global regulators have announced that, with limited exceptions, no new LIBOR-based contracts should be entered into after 2021. Actions by regulators have resulted in the establishment of alternative reference rates to LIBOR in most major currencies. Market participants are focused on the transition mechanisms by which the reference rate in existing contracts or instruments may be amended, whether through market wide protocols, fallback contractual provisions, bespoke negotiations or amendments, or otherwise. Markets are developing in response to these new rates, and questions around liquidity in these rates and how to appropriately adjust these rates to eliminate any economic value transfer at the time of transition remain a significant concern for the Fund. Neither the effect of the transition process nor its ultimate success can yet be known. The transition process may involve, among other things, increased volatility or illiquidity in markets for instruments that rely on LIBOR. In addition, uncertainty and volatility arising from the transition may result in a reduction in the value of certain LIBOR-based instruments held by the Fund or reduce the effectiveness of related transactions such as hedges. Any such effects of the transition away from LIBOR, as well as other unforeseen effects, could result in losses to the Fund.
Liquidity Risk Certain securities may be difficult (or impossible) to sell or certain positions may be difficult to close out at a desirable time and price, and the Fund may be required to hold an illiquid investment that is declining in value, or it may be required to sell certain illiquid investments at a price or time that is not advantageous in order to meet redemptions or other cash needs. Some securities may be subject to restrictions on resale. There can be no assurance that there will be a liquid market for instruments held by the Fund at any time. The Fund may not receive the proceeds from the sale of certain investments for an extended period.
Management Risk The Fund relies on the manager’s investment analysis and its selection of investments to achieve its investment objective. There can be no assurance that the Fund will achieve the intended results and the Fund may incur significant losses.
Market Risk The value of the Fund’s portfolio securities may decline, at times sharply and
​
− 28 −
TABLE OF CONTENTS
unpredictably, as a result of unfavorable market-induced changes affecting particular industries, sectors, or issuers. Stock and bond markets can decline significantly in response to issuer, market, economic, industry, political, regulatory, geopolitical, public health, and other conditions, as well as investor perceptions of these conditions. The Fund is subject to risks affecting issuers, such as management performance, financial leverage, industry problems, and reduced demand for goods or services.
Reinvestment Risk Income from the Fund’s portfolio will decline if and when the Fund invests the proceeds from matured, traded, or called debt obligations at market interest rates that are below the portfolio’s current earnings rate. A decline in income could affect the Fund’s overall return.
Repurchase Agreement Risk  These transactions must be fully collateralized, but involve credit risk to a Fund if the other party should default on its obligation and the Fund is delayed or prevented from recovering the collateral.
Restricted Securities Risk The Fund may hold securities that are restricted as to resale under the U.S. federal securities laws, such as securities in certain privately held companies. Such securities may be highly illiquid and their values may experience significant volatility. Restricted securities may be difficult to value.
Risk of Investment in Other Funds or Pools The Fund is indirectly exposed to all of the risks of the underlying funds, including ETFs, in which it invests, including the risk that the underlying funds will not perform as expected. ETFs are subject to additional risks, including secondary market trading risks and the risk that an ETF’s shares may trade above or below net asset value. The Fund indirectly pays a portion of the expenses incurred by the underlying funds.
Sector Risk The Fund may allocate more of its assets to particular industries or to particular economic, market, or industry sectors than to others. This could increase the volatility of the Fund’s portfolio, and the Fund’s performance may be more susceptible to developments affecting issuers in those industries or sectors than if the Fund invested more broadly.
Sovereign Debt Obligations Risk Investments in debt securities issued by governments or by government agencies and instrumentalities involve the risk that the governmental entities responsible
for repayment may be unable or unwilling to pay interest and repay principal when due. Many sovereign debt obligations may be rated below investment grade (“junk” or “high yield” bonds). Any restructuring of a sovereign debt obligation held by the Fund will likely have a significant adverse effect on the value of the obligation. In the event of default of sovereign debt, the Fund may be unable to pursue legal action against the sovereign issuer or to realize on collateral securing the debt.
U.S. Government Securities Risk Obligations of certain U.S. Government agencies and instrumentalities are not backed by the full faith and credit of the U.S. Government, and there can be no assurance that the U.S. Government would provide financial support to such agencies and instrumentalities.
Valuation Risk The Fund is subject to the risk of mispricing or improper valuation of its investments, in particular to the extent that its securities are fair valued.
When-Issued, Delayed Delivery, TBA, and Forward Commitment Transaction Risk These transactions may create leverage and involve a risk of loss if the value of the securities declines prior to settlement.
Performance Information
The following bar chart and table provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year for Class R5 shares. The table shows how the Fund’s average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance. Performance for Class R4 and Class R3 shares of the Fund for periods prior to their inception date (04/01/14) and performance for Class Y shares of the Fund for periods prior to its inception date (02/01/23) is based on the performance of Class R5 shares, adjusted for Class R4 and Class R3 shares to reflect Class R4 and Class R3 expenses, respectively. Performance for Class A shares of the Fund reflects any applicable sales charge. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. More up-to-date performance information is available at https://​www.massmutual.com/funds or by calling 1-888-309-3539.
​
− 29 −
TABLE OF CONTENTS
Annual Performance
Class R5 Shares
[MISSING IMAGE: hnh1u2j0u9goi9ic6v6ncj3gi2se.jpg]
​ Highest
Quarter:​ 		​ ​
2Q ’20,​
​ ​ ​ ​ 7.22% ​ ​ ​ Lowest
Quarter:​ 		​ ​
2Q ’22,​
​ ​
–7.98%
 ​
After-tax returns are calculated using the historical highest individual U.S. federal marginal income tax rates and do not reflect the impact of 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 not relevant to investors who hold Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class R5 only. After-tax returns for other classes will vary.
Average Annual Total Returns
(for the periods ended December 31, 2022)
​ ​ ​ ​ ​ ​ ​ ​
One
Year​
​ ​ ​
Five
Years​
​ ​ ​
Ten
Years​
​
Class R5​
​ ​ ​
Return Before
Taxes​
​ ​ ​ ​ ​ -16.70 % ​ ​ ​ ​ ​ ​ 0.18 % ​ ​ ​ ​ ​ ​ 1.40 % ​ ​
​ Return After Taxes on Distributions​ ​ ​ ​ ​ ​ -18.11 % ​ ​ ​ ​ ​ ​ -1.56 % ​ ​ ​ ​ ​ ​ -0.09 % ​ ​
​ Return After Taxes on Distributions and sales of Fund Shares​ ​ ​ ​ ​ ​ -9.86 % ​ ​ ​ ​ ​ ​ -0.44 % ​ ​ ​ ​ ​ ​ 0.50 % ​ ​
Class I​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -16.60 % ​ ​ ​ ​ ​ ​ 0.27 % ​ ​ ​ ​ ​ ​ 1.59 % ​ ​
Service Class​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -16.71 % ​ ​ ​ ​ ​ ​ 0.08 % ​ ​ ​ ​ ​ ​ 1.32 % ​ ​
Administrative
Class​ 		​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -16.81 % ​ ​ ​ ​ ​ ​ -0.02 % ​ ​ ​ ​ ​ ​ 1.21 % ​ ​
Class R4​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -16.95 % ​ ​ ​ ​ ​ ​ -0.15 % ​ ​ ​ ​ ​ ​ 1.06 % ​ ​
Class A​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -20.57 % ​ ​ ​ ​ ​ ​ -1.13 % ​ ​ ​ ​ ​ ​ 0.52 % ​ ​
Class R3​ ​ ​ ​ Return Before
Taxes​ 		​ ​ ​ ​ ​ -17.14 % ​ ​ ​ ​ ​ ​ -0.38 % ​ ​ ​ ​ ​ ​ 0.82 % ​ ​
Class Y ​ ​ ​ Return Before
Taxes 		​ ​ ​ ​ ​ -16.70 % ​ ​ ​ ​ ​ ​ 0.18 % ​ ​ ​ ​ ​ ​ 1.40 % ​ ​
Bloomberg U.S. Aggregate Bond
Index (reflects no deduction for
fees, expenses, or taxes)​ 		​ ​ ​ ​ ​ -13.01 % ​ ​ ​ ​ ​ ​ 0.02 % ​ ​ ​ ​ ​ ​ 1.06 % ​ ​
MANAGEMENT
Investment Adviser: MML Investment Advisers, LLC (“MML Advisers”)
Subadviser(s): Barings LLC (“Barings”)
Sub-subadviser(s):  Baring International Investment Limited (“BIIL”)
Portfolio Manager(s):
Yulia Alekseeva, CFA is a Managing Director, the Head of Securitized Credit Research, and a portfolio manager for Barings’ Investment Grade Fixed Income Group. She has managed the Fund since December 2020.
Stephen Ehrenberg, CFA is a Managing Director and portfolio manager for Barings’ Investment Grade Fixed Income Group. He has managed the Fund since November 2017.
Charles Sanford is a Managing Director and the Head of, and a portfolio manager for, Barings’ Investment Grade Credit Group. He has managed the Fund since December 2020. He previously managed the Fund from June 2006 to November 2017.
Douglas Trevallion, II, CFA is a Managing Director, the Head of Global Securitized Credit, and a portfolio manager for Barings’ Investment Grade Fixed Income Group. He has managed the Fund since June 2018.
PURCHASE AND SALE OF FUND SHARES
Shares of the Fund are generally available through distribution channels, such as broker-dealers or financial institutions, and to retirement plans, other institutional investors, and individual retirement accounts. Fund shares are redeemable on any business day by written request, telephone, or internet (available to certain customers).
Purchase Minimums*
 ​
​ ​ ​
Class Y
 ​
Initial Investment ​ ​
$100,000
​
Subsequent Investment ​ ​
$250
​
​
*
The Fund reserves the right to change or waive the investment minimums. For retirement plans, the investment minimum is $250 for each of the initial investment and subsequent investments.
​
TAX INFORMATION
The Fund intends to make distributions that may be taxed as ordinary income, qualified dividend income, or capital gains, unless you are an investor eligible for preferential tax treatment.
​
− 30 −
TABLE OF CONTENTS
PAYMENTS TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIES
If you purchase the Fund through a broker-dealer or other financial intermediary, the intermediary may receive a one-time or continuing payments from the Fund, MML Advisers or its affiliates, or others for the sale of Fund shares or continuing shareholder services provided by the intermediary.
These payments may create a conflict of interest by influencing the broker-dealer or other intermediary to recommend the Fund over another investment. You should contact your intermediary to obtain more information about the compensation it may receive in connection with your investment.
​
− 31 −
TABLE OF CONTENTS​
MassMutual Balanced Fund
INVESTMENT OBJECTIVE
The Fund seeks a high total return.
FEES AND EXPENSES OF THE FUND
This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay brokerage commissions and other fees to financial intermediaries which are not reflected in the tables and examples below. For Class A shares, you may qualify for sales charge discounts if you invest, or agree to invest in the future, at least $25,000 in MassMutual funds. More information about these and other discounts is available in the section titled Sales Charges by Class beginning on page 114 of the Fund’s Prospectus or from your financial professional.
Shareholder Fees (fees paid directly from your investment)
​ ​ ​
Class I​
​ ​
Class R5​
​ ​
Service
Class​
​ ​
Administrative
Class​
​ ​
Class R4​
​ ​
Class A​
​ ​
Class R3​
​ ​
Class Y
 ​
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)​
​ ​
None​
​ ​
None​
​ ​
None​
​ ​
None​
​ ​
None​
​ ​
5.50%​
​ ​
None​
​ ​
None
​
Maximum Deferred Sales Charge (Load) (as a % of the lower of the original offering price or redemption proceeds)​
​ ​
None​
​ ​
None​
​ ​
None​
​ ​
None​
​ ​
None​
​ ​
None​
​ ​
None
​ ​
None
​
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your
investment)
​ ​ ​
Class I​
​ ​
Class R5​
​ ​
Service
Class​
​ ​
Admini-
strative Class​
​ ​
Class R4​
​ ​
Class A​
​ ​
Class R3​
​ ​
Class Y
 ​
Management Fees​ ​ ​
0.48%
​ ​
0.48%
​ ​
0.48%
​ ​
0.48%
​ ​
0.48%
​ ​
0.48%
​ ​
0.48%
​ ​
0.48%
​
Distribution and Service (Rule 12b-1) Fees​
​ ​
None
​ ​
None
​ ​
None
​ ​
None
​ ​
0.25%
​ ​
0.25%
​ ​
0.50%
​ ​
None
​
Other Expenses​ ​ ​
0.22%
 ​ ​
0.32%
 ​ ​
0.42%
 ​ ​
0.52%
 ​ ​
0.42%
 ​ ​
0.52%
 ​ ​
0.42%
 ​ ​
0.32%(1)
 ​
Total Annual Fund Operating Expenses
 ​ ​
0.70%
 ​ ​
0.80%
 ​ ​
0.90%
 ​ ​
1.00%
 ​ ​
1.15%
 ​ ​
1.25%
 ​ ​
1.40%
 ​ ​
0.80%
 ​
​
(1)
Other Expenses are based on estimated amounts for the current fiscal year of the Fund.
​
Example
This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. It assumes that you invest $10,000 in each share class of the Fund for the time periods indicated and then redeem
all of your shares at the end of those periods. For Class A shares, the example includes the initial sales charge. The example also assumes that your investment earns a 5% return each year and that the Fund’s operating expenses are exactly as described in the preceding table. Although your
​
− 32 −
TABLE OF CONTENTS
actual costs may be higher or lower, based on these assumptions your costs would be:
​ ​ ​
1 Year​
​ ​
3 Years​
​ ​
5 Years​
​ ​
10 Years​
​
Class I ​ ​ ​ $ 72 ​ ​ ​ ​ $ 224 ​ ​ ​ ​ $ 390 ​ ​ ​ ​ $ 871 ​ ​
Class R5 ​ ​ ​ $ 82 ​ ​ ​ ​ $ 255 ​ ​ ​ ​ $ 444 ​ ​ ​ ​ $ 990 ​ ​
Service Class ​ ​ ​ $ 92 ​ ​ ​ ​ $ 287 ​ ​ ​ ​ $ 498 ​ ​ ​ ​ $ 1,108 ​ ​
Administrative Class
​ ​ ​ $ 102 ​ ​ ​ ​ $ 318 ​ ​ ​ ​ $ 552 ​ ​ ​ ​ $ 1,225 ​ ​
Class R4 ​ ​ ​ $ 117 ​ ​ ​ ​ $ 365 ​ ​ ​ ​ $ 633 ​ ​ ​ ​ $ 1,398 ​ ​
Class A ​ ​ ​ $ 670 ​ ​ ​ ​ $ 925 ​ ​ ​ ​ $ 1,199 ​ ​ ​ ​ $ 1,978 ​ ​
Class R3 ​ ​ ​ $ 143 ​ ​ ​ ​ $ 443 ​ ​ ​ ​ $ 766 ​ ​ ​ ​ $ 1,680 ​ ​
Class Y ​ ​ ​ $ 82 ​ ​ ​ ​ $ 255 ​ ​ ​ ​ $ 444 ​ ​ ​ ​ $ 990 ​ ​
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 higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 215% of the average value of its portfolio.
INVESTMENTS, RISKS, AND PERFORMANCE​
Principal Investment Strategies
The Fund seeks its investment objective by investing across different asset classes (U.S. equity securities and fixed income securities) each represented by a different segment of the Fund’s portfolio. Under normal market conditions, the Fund’s subadviser, Invesco Advisers, Inc., and sub-subadviser, Invesco Capital Management LLC (together with Invesco Advisers, Inc., “Invesco”), expect that 55%-75% of the Fund’s net assets will be invested in U.S. equity securities (the “U.S. Equity Segment”) and 25%-45% of the Fund’s net assets will be invested in fixed income securities (the “Bond Segment”) that meet certain environmental, social, and governance (“ESG”) criteria as described below. The Fund will target a long term strategic allocation of 65% to the U.S. Equity Segment and 35% to the Bond Segment. Invesco will periodically rebalance the portfolio back to these strategic weights. The Fund may at times have significant exposure to one or more industries or sectors. The Fund may purchase and sell securities on a when-issued, delayed delivery, to-be-announced, or forward commitment basis. The Fund may hold a portion of its assets in cash or cash equivalents.
Using an indexing strategy, Invesco generally will invest at least 80% of the Fund’s assets allocated to the U.S. Equity Segment in the equity securities of companies included within the Invesco US Large Cap Total Balanced Multi-Factor ESG Index* (the “Invesco Index”). Invesco Indexing LLC, an affiliate of Invesco, serves as the index provider for the Invesco Index.
The Invesco Index employs a factor-based model and is designed to select equity securities of U.S. large-capitalization companies that meet high ESG standards. The Invesco Index includes constituents of the Invesco Indexing Investable Universe (the “Investable Universe”) that are designated as U.S. large-capitalization securities in accordance with the Investable Universe methodology. Each eligible security is categorized by sector and assigned a score using a system established by Sustainalytics US Inc. (“Sustainalytics”), a third-party research
​
*
The “Invesco US Large Cap Total Balanced Multi-Factor ESG Index” and “Invesco Indexing” are the property of Invesco Indexing LLC and have been licensed for use by Invesco Capital Management LLC (“ICM”).
​
The shares (“Shares”) of the Fund (the “Product”) are not sponsored, endorsed, sold or promoted by Invesco Indexing LLC (“Licensor”). Licensor makes no representation or warranty, express or implied, to the owners of the Shares or any member of the public regarding the advisability of investing in securities generally or in the Shares particularly or the ability of the Invesco US Large Cap Total Balanced Multi-Factor ESG Index to track general stock market performance. Licensor is an affiliate of ICM and Invesco Advisers, Inc. (“Invesco Advisers”) and its relationship to ICM and Invesco Advisers includes the licensing of certain trademarks and trade names of Licensor and of the Invesco US Large Cap Total Balanced Multi-Factor ESG Index which is determined, composed and calculated by Licensor without regard to ICM, Invesco Advisers, the Product or the Shares. Licensor has no obligation to take the needs of the Licensee or the owners of the Shares into consideration in determining, composing or calculating the Invesco US Large Cap Total Balanced Multi-Factor ESG Index. Licensor is not responsible for and has not participated in any determination or calculation made with respect to issuance or redemption of the Shares. Licensor has no obligation or liability in connection with the administration, marketing or trading of the Shares.
Licensor does not guarantee the accuracy and/or the completeness of the Invesco US Large Cap Total Balanced Multi-Factor ESG Index and/or any data included therein. Licensor makes no warranty, express or implied, as to results to be obtained by ICM, Invesco Advisers, the Product or any owner of the Shares, or any other person or entity from the use of the Invesco US Large Cap Total Balanced Multi-Factor ESG Index or any data included therein in connection with the rights licensed hereunder or for any other use.
Licensor makes no express or implied warranties, and hereby expressly disclaims all warranties of merchantability or fitness for a particular purpose with respect to the Invesco US Large Cap Total Balanced Multi-Factor ESG Index or any data included therein. Without limiting any of the foregoing, in no event shall Licensor have any liability for any special, punitive, indirect, or consequential damages (including lost profits), even if notified of the possibility of such damages.
​
− 33 −
TABLE OF CONTENTS
provider that measures the strength of each pillar of ESG practices (the “ESG Score”). The top 75% of companies based on their ESG Scores within each sector are selected, while those in the tobacco, aerospace, coal, and pipeline industries, those in the bottom 10% by overall ESG Score, or those with a detrimental score for controversies, are excluded from the Invesco Index. The remaining securities are assigned a factor-based model score (the “Model Score”), which is computed by equal weighting the following individual factor scores:
Quality. A company’s quality factor score is based on an equally-weighted composite of three metrics: management quality (measured by the average quarterly percentage change in shares outstanding over the previous three years), earnings quality (measured by dividing the most recent year’s operating cash flow by the most recent year’s earnings), and operating quality (measured by dividing the most recent year’s aggregate gross income by the most recent year’s average total assets).
Value. A company’s value factor score is generally based on an equally-weighted composite of free cash flow yield, earnings yield, and book value of equity yield generally. For banks the value score is based on earnings yield and book value of equity yield and for real estate companies it is based on earnings yield, book value of equity yield, and funds from operations yield. Free cash flow, funds from operations, and earnings are measured over the previous year while book value is based on the most recent financial statement.
Price Momentum. A company’s price momentum factor score is based on the average monthly total return over the past nine months, excluding the most recent month, divided by the standard error of those total returns.
Low Volatility. A company’s low volatility factor score is based on the standard deviation of monthly total returns to a company’s stock price for the most recent 36-month period.
The Invesco Index constituents generally are weighted based on their market capitalizations and Model Scores. These weights are adjusted to ensure that each constituent and the Invesco Index as a whole satisfy certain constraints with respect to sector exposure, maximum security weights, and minimum security weights, as compared to a float-adjusted, market-capitalization weighted benchmark comprised of all of the U.S. large-capitalization securities of the Investable Universe.
The Invesco Index is rebalanced effective the third Friday in June and December. In addition, Invesco Index maintenance is performed effective the third Friday in March and September, during which constituents may be removed if they are no longer constituents of the Investable Universe, are within the tobacco, aerospace, coal, and pipeline industries, are in the bottom 10% by ESG Score, or have a detrimental score for controversies. The U.S. Equity Segment is rebalanced and maintained in accordance with the Invesco Index, meaning that it will buy and sell securities in response to changes in the Invesco Index.
Although the U.S. Equity Segment generally will invest in substantially all of the securities comprising the Invesco Index in proportion to their weightings in the Invesco Index, under various circumstances it may not be possible or practicable to purchase all of those securities in those same weightings. In those circumstances, the U.S. Equity Segment may hold cash or purchase a sample of the securities in the Invesco Index. When it relies on a “sampling” methodology, Invesco uses quantitative analysis to select securities from the Invesco Index universe to obtain a representative sample of securities that has, overall, investment characteristics similar to the Invesco Index in terms of key risk factors, performance attributes, and other characteristics such as industry weightings, market capitalization, return variability, earnings valuation, yield, and other financial characteristics of securities. When employing a sampling methodology, Invesco bases the number of the holdings in the U.S. Equity Segment on a number of factors, including asset size of the U.S. Equity Segment, and generally expects the U.S. Equity Segment to hold fewer than the total number of securities in the Invesco Index. However, Invesco reserves the right to invest in as many securities as it believes necessary to achieve the Fund’s investment objective. The U.S. Equity Segment may invest in common stocks, preferred stocks, exchange-traded funds (“ETFs”), or other equity securities. The U.S. Equity Segment may use futures contracts, a type of derivative, to seek performance that corresponds to the Invesco Index and/or to manage cash flows. Use of futures contracts by the U.S. Equity Segment may create investment leverage.
Fixed income securities in which the Bond Segment invests primarily include U.S. dollar-denominated debt securities that are rated investment grade at the time of purchase, meaning that they will be rated Baa3 or higher by Moody’s,
​
− 34 −
TABLE OF CONTENTS
BBB- or higher by Standard & Poor’s or the equivalent by any nationally recognized statistical rating organization (“NRSRO”). Debt securities in which the Bond Segment invests may include domestic and foreign corporate debt obligations, domestic and foreign government debt obligations, including U.S. Government securities, mortgage-related securities, asset-backed securities, and other debt obligations. The Bond Segment may also invest in unrated securities in which case Invesco may internally assign ratings to certain of those securities, after assessing their credit quality, in investment grade categories similar to those of NRSROs. There can be no assurance, nor is it intended, that Invesco’s credit analysis is consistent or comparable with the credit analysis process used by an NRSRO. In the event that a security receives different ratings from different NRSROs, the Bond Segment will treat the security as being rated in the highest rating category received from an NRSRO. The Bond Segment may invest in illiquid or thinly traded securities. The Bond Segment may also invest in securities that are subject to resale restrictions such as those contained in Rule 144A. The Bond Segment may invest up to 5% its assets in securities below investment grade (“junk” or “high yield” bonds), including securities in default. In the event that a security is downgraded after its purchase by the Bond Segment, the Bond Segment may continue to hold the security if Invesco considers that doing so would be consistent with the Fund’s investment objective. The Bond Segment may also enter into dollar roll transactions.
The Bond Segment may invest a portion of its assets in foreign debt securities, including securities issued by foreign governments or companies in both developed and emerging markets. The Bond Segment may not invest more than 20% of its net assets in foreign debt securities.
The Bond Segment has no limitations on the range of maturities of the debt securities in which it can invest and may hold securities with short-, medium-, or long-term maturities. The maturity of a security differs from its effective duration, which attempts to measure the expected volatility of a security’s price to interest rate changes. The Bond Segment may engage in treasury futures contracts in order to seek to enhance the Fund’s investment return or to try to manage investment risks. Use of treasury futures contracts by the Bond Segment may create investment leverage.
Invesco selects investments for the Bond Segment based on its analysis of opportunities and risks of various fixed income securities and market
sectors by focusing on business cycle analysis and relative values between corporate and government sectors. The Bond Segment mainly seeks income earnings on its investments plus capital appreciation that may arise from decreases in interest rates, from improving credit fundamentals for a particular sector or security, or from other investment techniques. Invesco may sell securities that it believes no longer meet the above criteria.
Additionally, as part of the credit selection and portfolio construction process, Invesco employs a proprietary framework for evaluating each issuer based on ESG criteria that, with respect to the Bond Segment, it has determined to be important in the investment selection process. Invesco has developed an ESG risk evaluation that is integrated into its core fundamental credit research process. As part of this process, corporate and government issuers are evaluated and assigned an overall ESG score based on separate “E,” “S,” and “G” factor scores, which are derived using a proprietary scoring system that involves a quantitative and qualitative assessment of  “E,” S,” and “G” factors. As part of this research process, Invesco may use third-party ESG ratings, company reporting, and engagement with management. If an issuer is determined by Invesco to have an overall ESG score that meets the applicable threshold that Invesco has established for that type of issuer, securities issued by it will be considered as a potential investment for the Bond Segment.
The ESG evaluation process for the Bond Segment also includes some exclusionary screening criteria which are intended to avoid investing in companies that are non-compliant with the UN Global Compact as well as companies that derive a significant portion of their revenue from: tobacco product manufacturing or distribution; extraction of fossil fuels from oil sands; mining or distribution of thermal coal; alcohol manufacturing or distribution; military contracting; manufacture of small arms including civilian firearms; provision of gambling products or services; or the provision of adult entertainment products or services. Additionally, companies involved in the following at any threshold are excluded: manufacture of nonconventional weapons including landmines and cluster munitions; or manufacture of nuclear, biological, or chemical weapons.
Invesco will monitor the “E,” “S,” and “G” factors of the Bond Segment’s holdings. If Invesco determines that a security’s overall ESG score has ceased to meet its threshold for inclusion in the Bond Segment, Invesco may sell that security,
​
− 35 −
TABLE OF CONTENTS
provided it can do so in an orderly manner given then-prevailing market conditions.
The Fund expects that it will engage in active and frequent trading and so will typically have a relatively high portfolio turnover rate.
Principal Risks
The following are the Principal Risks of the Fund. The value of your investment in the Fund could go down as well as up. You can lose money by investing in the Fund. References in this section to the Fund’s subadviser may include any sub-subadvisers as applicable. Certain risks relating to instruments and strategies used in the management of the Fund are placed first. The significance of any specific risk to an investment in the Fund will vary over time, depending on the composition of the Fund’s portfolio, market conditions, and other factors. You should read all of the risk information presented below carefully, because any one or more of these risks may result in losses to the Fund.
Equity Securities Risk Although stocks may have the potential to outperform other asset classes over the long term, their prices tend to fluctuate more dramatically over the shorter term. These movements may result from factors affecting individual companies, or from broader influences like changes in interest rates, market conditions, or investor confidence, or announcements of economic, political, or financial information.
Fixed Income Securities Risk The values of fixed income securities typically will decline during periods of rising interest rates, and can also decline in response to changes in the financial condition of the issuer, borrower, counterparty, or underlying collateral assets, or changes in market, economic, industry, political, regulatory, public health, and other conditions affecting a particular type of security or issuer or fixed income securities generally. Certain events, such as market or economic developments, regulatory or government actions, natural disasters, pandemics, terrorist attacks, war, and other geopolitical events can have a dramatic adverse effect on the debt market and the overall liquidity of the market for fixed income securities. During those periods, the Fund may experience high levels of shareholder redemptions, and may have to sell securities at times when the Fund would otherwise not do so, and potentially at unfavorable prices. Certain securities may be difficult to value during such periods. Fixed income securities are subject to interest rate risk (the risk
that the value of a fixed income security will fall when interest rates rise), extension risk (the risk that the average life of a security will be extended through a slowing of principal payments), prepayment risk (the risk that a security will be prepaid and the Fund will be required to reinvest at a less favorable rate), duration risk (the risk that longer-term securities may be more sensitive to interest rate changes), inflation risk (the risk that as inflation increases, the present value of the Fund’s fixed income investment typically will decline), and credit risk.
Derivatives Risk Derivatives can be highly volatile and involve risks different from, and potentially greater than, direct investments, including risks of imperfect correlation between the value of derivatives and underlying assets, counterparty default, potential losses that partially or completely offset gains, and illiquidity. Derivatives can create investment leverage. Losses from derivatives can be substantially greater than the derivatives’ original cost and can sometimes be unlimited. If the value of a derivative does not correlate well with the particular market or asset class the derivative is designed to provide exposure to, the derivative may not have the effect or benefit anticipated. Derivatives can also reduce the opportunity for gains or result in losses by offsetting positive returns in other investments. Many derivatives are traded in the over-the-counter market and not on exchanges.
Foreign Investment Risk; Emerging Markets Risk; Currency Risk Investments in securities of foreign issuers, securities of companies with significant foreign exposure, and foreign currencies can involve additional risks relating to market, industry, political, regulatory, public health, and other conditions. Political, social, diplomatic, and economic developments, U.S. and foreign government action, or threat thereof, such as the imposition of currency or capital blockages, controls, or tariffs, economic and trade sanctions or embargoes, security trading suspensions, entering or exiting trade or other intergovernmental agreements, or the expropriation or nationalization of assets in a particular country, can cause dramatic declines in certain or all securities with exposure to that country and other countries. In the event of nationalization, expropriation, confiscation, or other government action, intervention, or restriction, the Fund could lose its entire investment in a particular foreign issuer or country. There may be quotas or other limits on the ability of the Fund (or clients of the Fund’s
​
− 36 −
TABLE OF CONTENTS
investment adviser or subadviser) to invest or maintain investments in securities of issuers in certain countries. Enforcing legal rights can be more difficult, costly, and limited in certain foreign countries and with respect to certain types of investments, and can be particularly difficult against foreign governments. Because non-U.S. securities are normally denominated and traded in currencies other than the U.S. dollar, the value of the Fund’s assets may be affected favorably or unfavorably by changes in currency exchange rates, exchange control regulations, and restrictions or prohibitions on the repatriation of non-U.S. currencies. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. company than about a U.S. company, and many non-U.S. companies are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the U.S. The securities of some non-U.S. companies, especially those in emerging markets, are less liquid and at times more volatile than securities of comparable U.S. companies. Emerging markets securities are subject to greater risks than securities issued in developed foreign markets, including less liquidity, less stringent investor protection and disclosure standards, less reliable settlement practices, greater price volatility, higher relative rates of inflation, greater political, economic, and social instability, greater custody and operational risks, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments, and greater volatility in currency exchange rates, and are more susceptible to environmental problems. Many emerging market countries are highly reliant on international trade and exports, including the export of commodities. Their economies may be significantly impacted by fluctuations in commodity prices and the global demand for certain commodities. In addition, pandemics and outbreaks of contagious diseases may exacerbate pre-existing problems in emerging market countries with less established health care systems. Frontier markets, a subset of emerging markets, generally have smaller economies and less mature capital markets than emerging markets. As a result, the risks of investing in emerging market countries are magnified in frontier market countries. Frontier markets are more susceptible to having abrupt changes in currency values, less mature markets and settlement practices, and lower trading volumes that could lead to greater price volatility and
illiquidity. Non-U.S. transaction costs, such as brokerage commissions and custody costs, may be higher than in the United States. In addition, foreign markets can react differently to market, economic, industry, political, regulatory, geopolitical, public health, and other conditions than the U.S. market.
Below Investment Grade Debt Securities Risk Below investment grade debt securities, commonly known as “junk” or “high yield” bonds, have speculative characteristics and involve greater volatility of price and yield, greater risk of loss of principal and interest, and generally reflect a greater possibility of an adverse change in financial condition that could affect an issuer’s ability to honor its obligations.
Cash Position Risk If the Fund holds a significant portion of its assets in cash or cash equivalents, its investment returns may be adversely affected and the Fund may not achieve its investment objective.
Credit Risk Credit risk is the risk that an issuer, guarantor, or liquidity provider of a fixed income security held by the Fund may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. The Fund may also be exposed to the credit risk of its counterparty to repurchase agreements, reverse repurchase agreements, swap transactions, and other derivatives transactions, and to the counterparty’s ability or willingness to perform in accordance with the terms of the transaction. The value of such transactions to the Fund will depend on the willingness and ability of the counterparty to perform its obligations, including among other things the obligation to return collateral or margin to the Fund. If a counterparty becomes bankrupt or otherwise fails to perform its obligations under a derivative contract due to financial difficulties, the Fund may experience significant delays in obtaining any recovery under the derivative contract in a bankruptcy or other reorganization proceeding. The Fund may obtain only a limited recovery or may obtain no recovery in such circumstances.
Defaulted and Distressed Securities Risk Because the issuer of such securities is in default and is likely to be in distressed financial condition, repayment of defaulted securities and obligations of distressed issuers (including insolvent issuers
​
− 37 −
TABLE OF CONTENTS
or issuers in payment or covenant default, in workout or restructuring, or in bankruptcy or insolvency proceedings) is uncertain. To the extent the Fund is invested in distressed securities, its ability to achieve current income for its shareholders may be diminished.
Dollar Roll Transaction Risk Dollar roll transactions generally create leverage and subject the Fund to the credit risk of the counterparty.
ESG Risk Because the Invesco Index and the Bond Segment use ESG factors to assess and exclude certain investments for non-financial reasons, the Fund may forgo some market opportunities available to funds that do not use these factors. The securities of companies with favorable ESG scores may underperform similar companies that do not score as well or may underperform the stock market as a whole. As a result, the Fund may underperform funds that do not screen or score companies based on ESG factors or funds that use a different ESG methodology. Information used to evaluate such ESG factors may not be readily available, complete, or accurate, which could negatively impact the Fund’s performance. In addition, a company’s ESG score may differ from that assigned by other funds or an investor. As a result, the companies deemed eligible for inclusion in the Fund’s portfolio may not reflect the beliefs or values of any particular investor and may not be deemed to exhibit positive or favorable ESG characteristics if different metrics were used to evaluate them.
Frequent Trading/Portfolio Turnover Risk Portfolio turnover generally involves some expense to the Fund and may result in the realization of taxable capital gains (including short-term gains). The trading costs and tax effects associated with portfolio turnover may adversely affect the Fund’s performance.
Indexing Risk The U.S. Equity Segment’s performance may not track the performance of the Invesco Index due to a number of factors, including fees and expenses of the Fund, the Fund’s cash positions, and differences between securities held by the U.S. Equity Seqment and the securities comprising the Invesco Index which may result from legal restrictions, costs, or liquidity constraints, especially during times when a sampling methodology is used.
Large Company Risk Large-capitalization stocks as a group could fall out of favor with the market, causing the Fund’s investments in large-capitalization stocks to underperform investments
that focus on small- or medium-capitalization stocks. Larger, more established companies may be slow to respond to challenges and may grow more slowly than smaller companies.
Leveraging Risk Instruments and transactions, including derivatives and dollar roll transactions, that create leverage may cause the value of an investment in the Fund to be more volatile, could result in larger losses than if they were not used, and tend to compound the effects of other risks.
Liquidity Risk Certain securities may be difficult (or impossible) to sell or certain positions may be difficult to close out at a desirable time and price, and the Fund may be required to hold an illiquid investment that is declining in value, or it may be required to sell certain illiquid investments at a price or time that is not advantageous in order to meet redemptions or other cash needs. Some securities may be subject to restrictions on resale. There can be no assurance that there will be a liquid market for instruments held by the Fund at any time. The Fund may not receive the proceeds from the sale of certain investments for an extended period.
Management Risk The Fund relies on the manager’s investment analysis and its selection of investments to achieve its investment objective. There can be no assurance that the Fund will achieve the intended results and the Fund may incur significant losses.
Market Risk The value of the Fund’s portfolio securities may decline, at times sharply and unpredictably, as a result of unfavorable market-induced changes affecting particular industries, sectors, or issuers. Stock and bond markets can decline significantly in response to issuer, market, economic, industry, political, regulatory, geopolitical, public health, and other conditions, as well as investor perceptions of these conditions. The Fund is subject to risks affecting issuers, such as management performance, financial leverage, industry problems, and reduced demand for goods or services.
Mortgage- and Asset-Backed Securities Risk Investments in mortgage- and asset-backed securities subject the Fund to credit risk, interest rate risk, extension risk, and prepayment risk, among other risks. Mortgage-backed and asset-backed securities not issued by a government agency generally involve greater credit risk than securities issued by government agencies. Payment of principal and interest generally depends on
​
− 38 −
TABLE OF CONTENTS
the cash flows generated by the underlying assets and the terms of the security. The types of mortgages (for example, residential or commercial mortgages) underlying securities held by the Fund may differ and be affected differently by market factors. Investments that receive only the interest portion or the principal portion of payments on the underlying assets may be highly volatile. Litigation with respect to the representations and warranties given in connection with the issuance of mortgage-backed securities can be an important consideration in investing in such securities, and the outcome of any such litigation could significantly impact the value of the Fund’s mortgage-backed investments.
Passive Management Risk With an indexing strategy, there is no attempt to seek returns in excess of a benchmark index, to use defensive strategies, or to reduce the effects of any long-term poor investment performance. Therefore, with respect to the U.S. Equity Segment, the Fund would not necessarily buy or sell a security unless that security is added to, or removed from, the Invesco Index, even if that security generally is underperforming.
Preferred Stock Risk Like other equity securities, preferred stock is subject to the risk that its value may decrease based on actual or perceived changes in the business or financial condition of the issuer. In addition, changes in interest rates may adversely affect the value of a preferred stock that pays a fixed dividend. Preferred stocks are also subject to additional risks, such as potentially greater volatility and risks related to deferral, non-cumulative dividends, subordination, liquidity, limited voting rights, and special redemption rights.
Restricted Securities Risk The Fund may hold securities that are restricted as to resale under the U.S. federal securities laws, such as securities in certain privately held companies. Such securities may be highly illiquid and their values may experience significant volatility. Restricted securities may be difficult to value.
Risk of Investment in Other Funds or Pools The Fund is indirectly exposed to all of the risks of the underlying funds, including ETFs, in which it invests, including the risk that the underlying funds will not perform as expected. ETFs are subject to additional risks, including secondary market trading risks and the risk that an ETF’s shares may trade above or below net asset value. The Fund indirectly pays a portion of the expenses incurred by the underlying funds.
Sector Risk The Fund may allocate more of its assets to particular industries or to particular economic, market, or industry sectors than to others. This could increase the volatility of the Fund’s portfolio, and the Fund’s performance may be more susceptible to developments affecting issuers in those industries or sectors than if the Fund invested more broadly.
U.S. Government Securities Risk Obligations of certain U.S. Government agencies and instrumentalities are not backed by the full faith and credit of the U.S. Government, and there can be no assurance that the U.S. Government would provide financial support to such agencies and instrumentalities.
Valuation Risk The Fund is subject to the risk of mispricing or improper valuation of its investments, in particular to the extent that its securities are fair valued.
When-Issued, Delayed Delivery, TBA, and Forward Commitment Transaction Risk These transactions may create leverage and involve a risk of loss if the value of the securities declines prior to settlement.
Performance Information
The following bar chart and table provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year for Class R5 shares. The table shows how the Fund’s average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance and three additional indexes, including an index that provides a comparison relevant to the Fund’s allocation to fixed income investments (Bloomberg U.S. Aggregate Bond Index), an index of funds with similar investment objectives (Lipper Balanced Fund Index), and a hypothetical custom index which comprises the S&P 500® (65%) and Bloomberg U.S. Aggregate Bond (35%) Indexes (Custom Balanced Index). The Fund’s investment objective and investment strategy changed on November 18, 2020. The performance results shown below would not necessarily have been achieved had the Fund’s current investment strategy been in effect for the entire period for which performance results are presented. Performance for Class I, Class R4, and Class R3 shares of the Fund for periods prior to their inception date (04/01/14) and performance for Class Y shares of the Fund for periods prior to its inception date (02/01/23) is based on the
​
− 39 −
TABLE OF CONTENTS
performance of Class R5 shares, adjusted for Class R4 and Class R3 shares to reflect Class R4 and Class R3 expenses, respectively. Performance for Class A shares of the Fund reflects any applicable sales charge. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. More up-to-date performance information is available at https://​www.massmutual.com/funds or by calling 1-888-309-3539.
Annual Performance
Class R5 Shares
[MISSING IMAGE: mkqrm9oh9btplaorujjhnhqgt97f.jpg]
​ Highest
Quarter:​ 		​ ​
2Q ’20,​
​ ​ ​