This Fund seeks current income exempt from U.S. federal income tax.

​

(1)

Applies only to certain redemptions of shares bought with no front-end sales charge. Class A shares purchased without a front-end sales charge in accounts aggregating $250,000 or more may be subject to a 1.00% contingent deferred sales charge if the shares are tendered and accepted for repurchase within 18 months of purchase. The 18-month period begins on the day on which the purchase is made.

​

​

(1)

The expenses in the above table reflect a written agreement by MML Advisers to cap the fees and expenses of the Fund (other than extraordinary legal and other expenses, Acquired Fund Fees and Expenses, interest expense, expenses related to borrowings, securities lending, leverage, taxes, and

​

brokerage, short sale dividend and loan expense, or other non-recurring or unusual expenses such as organizational expenses and shareholder meeting expenses, as applicable) through January 31, 2026, to the extent that Total Annual Fund Operating Expenses after Expense Reimbursement would otherwise exceed 0.29%, 0.39%, and 0.64% for Classes I, Y, and A, respectively. The Total Annual Fund Operating Expenses after Expense Reimbursement shown in the above table may exceed these amounts, because, as noted in the previous sentence, certain fees and expenses are excluded from the cap. The agreement can only be terminated by mutual consent of the Board of Trustees on behalf of the Fund and MML Advisers.

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 front-end 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 actual costs may be higher or lower, based on these assumptions your costs would be:

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. For the period February 1, 2024 (commencement of operations) through September 30, 2024, the Fund’s portfolio turnover rate was 70% of the average value of its portfolio.

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 municipal debt securities, the income from which is exempt from U.S. federal income tax. Interest from the Fund’s investment may be subject to the U.S. federal alternative minimum tax.

Municipal debt securities include bonds issued by, or on behalf of, the District of Columbia, the states, the territories (including Puerto Rico, Guam, and the U.S. Virgin Islands), commonwealths, and possessions of the United States and their political subdivisions, and agencies, authorities, and instrumentalities. Municipal debt securities also include general obligation bonds, revenue bonds, industrial revenue bonds, industrial development bonds, private activity bonds, as well as short-term, tax-exempt obligations such as municipal notes and variable rate demand obligations. The Fund may invest without limit in obligations the income from which is subject to the U.S. federal alternative minimum tax, and all distributions by the Fund, including any distributions derived from tax-exempt municipal obligations, may be included in taxable income for purposes of the U.S. federal alternative minimum tax.

The Fund invests, under normal circumstances, its net assets primarily in municipal debt securities that are, at the time of purchase, rated investment grade by at least one credit rating agency (rated Baa3 or higher by Moody’s Investors Service, Inc. (“Moody’s”), BBB- or higher by S&P Global Ratings, a subsidiary of S&P Global (“Standard & Poor’s”), or the equivalent by any other nationally recognized statistical rating organization, or, if unrated, determined to be of comparable quality by the Fund’s subadviser, Clinton Investment Management, LLC (“Clinton”)). The Fund will not invest more than 30% of its net assets in obligations rated below investment grade (at the time of purchase, rated below Baa3/BBB- or the equivalent by each nationally recognized statistical rating organization rating the security, including securities in default, or, if unrated, determined to be of comparable quality by the Fund’s subadviser). In the event that a security is downgraded after its purchase by the Fund, the Fund may continue to hold the security if the Fund’s subadviser considers that doing so would be consistent with the Fund’s investment objective. For purposes of rating restrictions, if securities are rated differently by two or more rating agencies, the highest rating is used. Debt securities rated below investment grade (e.g., below Baa3 by Moody’s or below BBB- by Standard & Poor’s) are commonly referred to as “junk” or “high yield” bonds.

The Fund may invest up to 20% of its net assets in other debt obligations, including (but not limited to) taxable municipal obligations, U.S. Treasury securities, and obligations of the U.S. Government, its agencies and instrumentalities.

The Fund may invest a significant percentage of its net assets in issuers in a single state, territory, or possession, or a small number of states, territories, or possessions. The Fund may at times have significant exposure to one or more industries or sectors.

The Fund may use derivatives, including U.S. Treasury futures, to seek to enhance the Fund’s investment return or for hedging purposes. The Fund is not required to use derivatives in seeking its investment objective or for hedging and might not do so. 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, including reverse repurchase agreement transactions. The Fund may hold a portion of its assets in cash or cash equivalents.

Clinton intends for the Fund’s portfolio dollar-weighted average duration generally to match (within 30%) the average duration of the Bloomberg 5-Year Municipal Bond Index (as of December 31, 2024, the average duration of the Index was 3.70 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. The average maturity of the Fund’s investments is typically expected to be less than 5 years, however, the Fund may invest in securities of any maturity.

risk through diversification across the credit spectrum and bond structures, while allowing Clinton to better recognize investment opportunities.

Principal Risks

Municipal Obligations Risk The amount of public information available about municipal obligations is generally less than for corporate equities or bonds, meaning that the investment performance of municipal obligations may be more dependent on the analytical abilities of the investment adviser than stock or corporate bond investments. The secondary market for municipal obligations also tends to be less well-developed and less liquid than many other securities markets, which may limit the Fund’s ability to sell its municipal obligations at attractive prices. Because many municipal instruments are issued to finance similar projects, conditions in certain industries can significantly affect the Fund and the overall municipal market. The differences between the price at which an obligation can be purchased and the price at which it can be sold may widen during periods of market distress or volatility. Less liquid obligations can become more difficult to value and be subject to erratic price movements. The increased presence of non-traditional participants (such as proprietary trading desks of investment banks and hedge funds) or the absence of traditional participants (such as individuals, insurance companies, banks, and life insurance companies) in the municipal markets may lead to greater volatility in the markets because non-traditional participants may trade more frequently or in greater volume.

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.

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.

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.

the Fund is invested in distressed securities, its ability to achieve current income for its shareholders may be diminished.

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.

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.

will achieve the intended results and the Fund may incur significant losses. The Fund also runs the risk that deficiencies in the investment adviser’s, subadviser’s, or another service provider’s internal systems or controls will cause losses for the Fund or impair Fund operations.

Reverse Repurchase Agreement Transaction Risk These transactions typically create leverage and subject the Fund to the credit risk of the counterparty.

changes in tax laws, adverse interpretations by the relevant taxing authority, court decisions, or the non-compliant conduct of the issuer of an obligation. If there is a determination that an issuer of a tax-exempt municipal obligation has not complied with applicable requirements, interest from the obligation could become subject to regular U.S. federal income tax, possibly retroactively to the date the obligation was issued, the value of the obligation could decline significantly, and all or a portion of the Fund’s distributions to shareholders could be recharacterized as taxable. Some of the Fund’s income distributions may be subject to regular U.S. federal income tax, and distributions of any capital gains generally will be subject to regular U.S. federal income tax. All or a portion of the Fund’s tax-exempt distributions may nevertheless be taken into account for purposes of the U.S. federal alternative minimum tax. In addition, distributions of the Fund’s income and capital gains maybe subject to non-U.S., state, and local taxes.

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.

Performance Information

Fund, along with the performance of the Bloomberg Municipal Bond Index as a primary index and the Bloomberg 5-Year Municipal Bond Index as a secondary index, will be available after the Fund has been in operation for one calendar year.

Investment Adviser: MML Investment Advisers, LLC (“MML Advisers”)

Subadviser(s): Clinton Investment Management, LLC (“Clinton”)

Portfolio Manager(s):

Andrew Clinton is the Chief Executive Officer, Chief Investment Officer, and Lead Portfolio Manager at Clinton. He has managed the Fund since February 2024.

Mark Steffen is a Director and Portfolio Manager at Clinton. He has managed the Fund since February 2024.

Shares of the Fund are generally available through various financial intermediaries, such as retirement plan recordkeepers, broker-dealers, financial institutions, and insurance companies, and to 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).

​

*

The Fund reserves the right to change or waive the investment minimums. Class I shares do not have investment minimums and there are no initial or subsequent investment minimums for retirement plans.

​

The Fund intends to distribute income that is exempt from U.S. federal income tax, but may be subject to U.S. federal alternative minimum tax. A portion of the Fund’s distributions may be subject to U.S. federal income tax.

This Fund seeks current income exempt from U.S. federal income tax.

​

(1)

Applies only to certain redemptions of shares bought with no front-end sales charge. Class A shares purchased without a front-end sales charge in accounts aggregating $250,000 or more may be subject to a 1.00% contingent deferred sales charge if the shares are tendered and accepted for repurchase within 18 months of purchase. The 18-month period begins on the day on which the purchase is made.

​

​

(1)

The expenses in the above table reflect a written agreement by MML Advisers to cap the fees and expenses of the Fund (other than extraordinary legal and other expenses, Acquired Fund Fees and Expenses, interest expense, expenses related to borrowings, securities lending, leverage, taxes, and

​

brokerage, short sale dividend and loan expense, or other non-recurring or unusual expenses such as organizational expenses and shareholder meeting expenses, as applicable) through January 31, 2026, to the extent that Total Annual Fund Operating Expenses after Expense Reimbursement would otherwise exceed 0.41%, 0.51%, and 0.76% for Classes I, Y, and A, respectively. The Total Annual Fund Operating Expenses after Expense Reimbursement shown in the above table may exceed these amounts, because, as noted in the previous sentence, certain fees and expenses are excluded from the cap. The agreement can only be terminated by mutual consent of the Board of Trustees on behalf of the Fund and MML Advisers.

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 front-end 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 actual costs may be higher or lower, based on these assumptions your costs would be:

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. For the period February 1, 2024 (commencement of operations) through September 30, 2024, the Fund’s portfolio turnover rate was 76% of the average value of its portfolio.

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 municipal debt securities, the income from which is exempt from U.S. federal income tax. Interest from the Fund’s investment may be subject to the U.S. federal alternative minimum tax.

Municipal debt securities include bonds issued by, or on behalf of, the District of Columbia, the states, the territories (including Puerto Rico, Guam, and the U.S. Virgin Islands), commonwealths, and possessions of the United States and their political subdivisions, and agencies, authorities, and instrumentalities. Municipal debt securities also include general obligation bonds, revenue bonds, industrial revenue bonds, industrial development bonds, private activity bonds, as well as short-term, tax-exempt obligations such as municipal notes and variable rate demand obligations. The Fund may invest without limit in obligations the income from which is subject to the U.S. federal alternative minimum tax, and all distributions by the Fund, including any distributions derived from tax-exempt municipal obligations, may be included in taxable income for purposes of the U.S. federal alternative minimum tax.

The Fund invests, under normal circumstances, its net assets primarily in municipal debt securities that are, at the time of purchase, rated investment grade by at least one credit rating agency (rated Baa3 or higher by Moody’s Investors Service, Inc. (“Moody’s”), BBB- or higher by S&P Global Ratings, a subsidiary of S&P Global (“Standard & Poor’s”), or the equivalent by any other nationally recognized statistical rating organization, or, if unrated, determined to be of comparable quality by the Fund’s subadviser, Clinton Investment Management, LLC (“Clinton”)). The Fund will not invest more than 30% of its net assets in obligations rated below investment grade (at the time of purchase, rated below Baa3/BBB- or the equivalent by each nationally recognized statistical rating organization rating the security, including securities in default, or, if unrated, determined to be of comparable quality by the Fund’s subadviser). In the event that a security is downgraded after its purchase by the Fund, the Fund may continue to hold the security if the Fund’s subadviser considers that doing so would be consistent with the Fund’s investment objective. For purposes of rating restrictions, if securities are rated differently by two or more rating agencies, the highest rating is used. Debt securities rated below investment grade (e.g., below Baa3 by Moody’s or below BBB- by Standard & Poor’s) are commonly referred to as “junk” or “high yield” bonds.

The Fund may invest up to 20% of its net assets in other debt obligations, including (but not limited to) taxable municipal obligations, U.S. Treasury securities, and obligations of the U.S. Government, its agencies and instrumentalities.

The Fund may invest a significant percentage of its net assets in issuers in a single state, territory, or possession, or a small number of states, territories, or possessions. The Fund may at times have significant exposure to one or more industries or sectors.

The Fund may use derivatives, including U.S. Treasury futures, to seek to enhance the Fund’s investment return or for hedging purposes. The Fund is not required to use derivatives in seeking its investment objective or for hedging and might not do so. 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, including reverse repurchase agreement transactions. The Fund may hold a portion of its assets in cash or cash equivalents.

Clinton intends for the Fund’s portfolio dollar-weighted average duration generally to match (within 30%) the average duration of the Bloomberg Municipal Bond Index (as of December 31, 2024, the average duration of the Index was 6.21 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. The average maturity of the Fund’s investments is typically expected to be less than 12 years, however, the Fund may invest in securities of any maturity.

risk through diversification across the credit spectrum and bond structures, while allowing Clinton to better recognize investment opportunities.

Principal Risks

Municipal Obligations Risk The amount of public information available about municipal obligations is generally less than for corporate equities or bonds, meaning that the investment performance of municipal obligations may be more dependent on the analytical abilities of the investment adviser than stock or corporate bond investments. The secondary market for municipal obligations also tends to be less well-developed and less liquid than many other securities markets, which may limit the Fund’s ability to sell its municipal obligations at attractive prices. Because many municipal instruments are issued to finance similar projects, conditions in certain industries can significantly affect the Fund and the overall municipal market. The differences between the price at which an obligation can be purchased and the price at which it can be sold may widen during periods of market distress or volatility. Less liquid obligations can become more difficult to value and be subject to erratic price movements. The increased presence of non-traditional participants (such as proprietary trading desks of investment banks and hedge funds) or the absence of traditional participants (such as individuals, insurance companies, banks, and life insurance companies) in the municipal markets may lead to greater volatility in the markets because non-traditional participants may trade more frequently or in greater volume.

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.

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.

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.

the Fund is invested in distressed securities, its ability to achieve current income for its shareholders may be diminished.

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.

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.

will achieve the intended results and the Fund may incur significant losses. The Fund also runs the risk that deficiencies in the investment adviser’s, subadviser’s, or another service provider’s internal systems or controls will cause losses for the Fund or impair Fund operations.

Reverse Repurchase Agreement Transaction Risk These transactions typically create leverage and subject the Fund to the credit risk of the counterparty.

changes in tax laws, adverse interpretations by the relevant taxing authority, court decisions, or the non-compliant conduct of the issuer of an obligation. If there is a determination that an issuer of a tax-exempt municipal obligation has not complied with applicable requirements, interest from the obligation could become subject to regular U.S. federal income tax, possibly retroactively to the date the obligation was issued, the value of the obligation could decline significantly, and all or a portion of the Fund’s distributions to shareholders could be recharacterized as taxable. Some of the Fund’s income distributions may be subject to regular U.S. federal income tax, and distributions of any capital gains generally will be subject to regular U.S. federal income tax. All or a portion of the Fund’s tax-exempt distributions may nevertheless be taken into account for purposes of the U.S. federal alternative minimum tax. In addition, distributions of the Fund’s income and capital gains maybe subject to non-U.S., state, and local taxes.

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.

Performance Information

Fund, along with the performance of the Bloomberg Municipal Bond Index, will be available after the Fund has been in operation for one calendar year.

Investment Adviser: MML Investment Advisers, LLC (“MML Advisers”)

Subadviser(s): Clinton Investment Management, LLC (“Clinton”)

Portfolio Manager(s):

Andrew Clinton is the Chief Executive Officer, Chief Investment Officer, and Lead Portfolio Manager at Clinton. He has managed the Fund since February 2024.

Mark Steffen is a Director and Portfolio Manager at Clinton. He has managed the Fund since February 2024.

Shares of the Fund are generally available through various financial intermediaries, such as retirement plan recordkeepers, broker-dealers, financial institutions, and insurance companies, and to 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).

​

*

The Fund reserves the right to change or waive the investment minimums. Class I shares do not have investment minimums and there are no initial or subsequent investment minimums for retirement plans.

​

The Fund intends to distribute income that is exempt from U.S. federal income tax, but may be subject to U.S. federal alternative minimum tax. A portion of the Fund’s distributions may be subject to U.S. federal income tax.

This Fund seeks high current income exempt from U.S. federal income tax. The Fund’s secondary investment objective is total return.

​

(1)

Applies only to certain redemptions of shares bought with no front-end sales charge. Class A shares purchased without a front-end sales charge in accounts aggregating $250,000 or more may be subject to a 1.00% contingent deferred sales charge if the shares are tendered and accepted for repurchase within 18 months of purchase. The 18-month period begins on the day on which the purchase is made.

​

​

(1)

The expenses in the above table reflect a written agreement by MML Advisers to cap the fees and expenses of the Fund (other than extraordinary legal and other expenses, Acquired Fund Fees and Expenses, interest expense, expenses related

​

to borrowings, securities lending, leverage, taxes, and brokerage, short sale dividend and loan expense, or other non-recurring or unusual expenses such as organizational expenses and shareholder meeting expenses, as applicable) through January 31, 2026, to the extent that Total Annual Fund Operating Expenses after Expense Reimbursement would otherwise exceed 0.54%, 0.64%, and 0.89% for Classes I, Y and, A, respectively. The Total Annual Fund Operating Expenses after Expense Reimbursement shown in the above table may exceed these amounts, because, as noted in the previous sentence, certain fees and expenses are excluded from the cap. The agreement can only be terminated by mutual consent of the Board of Trustees on behalf of the Fund and MML Advisers.

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 front-end 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 actual costs may be higher or lower, based on these assumptions your costs would be:

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. For the period February 1, 2024 (commencement of operations) through September 30, 2024, the Fund’s portfolio turnover rate was 121% of the average value of its portfolio.

Principal Investment Strategies

from the Fund’s investment may be subject to the U.S. federal alternative minimum tax.

Municipal debt securities include bonds issued by, or on behalf of, the District of Columbia, the states, the territories (including Puerto Rico, Guam, and the U.S. Virgin Islands), commonwealths, and possessions of the United States and their political subdivisions, and agencies, authorities, and instrumentalities. Municipal debt securities also include general obligation bonds, revenue bonds, industrial revenue bonds, industrial development bonds, private activity bonds, as well as short-term, tax-exempt obligations such as municipal notes and variable rate demand obligations. The Fund may invest without limit in obligations the income from which is subject to the U.S. federal alternative minimum tax, and all distributions by the Fund, including any distributions derived from tax-exempt municipal obligations, may be included in taxable income for purposes of the U.S. federal alternative minimum tax.

The Fund invests, under normal circumstances, at least 35% of its net assets in municipal debt securities that are, at the time of purchase, rated by at least one credit rating agency as follows: Baa or lower by Moody’s Investors Service, Inc. (“Moody’s”), BBB or lower by S&P Global Ratings, a subsidiary of S&P Global (“Standard & Poor’s”), or the equivalent by any other nationally recognized statistical rating organization, including securities in default, or, if unrated, determined to be of comparable quality by the Fund’s subadviser, Clinton Investment Management, LLC (“Clinton”). For purposes of rating restrictions, if securities are rated differently by two or more rating agencies, the lowest rating is used. The Fund may invest less than 35% of its net assets in municipal debt securities rated at or below these ratings if the Fund’s subadviser determines that there is an insufficient supply of such investment opportunities available that are appropriate for investment or for temporary defensive measures. The Fund may invest up to 45% of its net assets in municipal debt securities rated below investment grade (e.g., below Baa3 by Moody’s or below BBB- by Standard & Poor’s), which are commonly referred to as “junk” or “high yield” bonds.

The Fund may invest up to 20% of its net assets in other debt obligations, including (but not limited to) taxable municipal obligations, U.S. Treasury securities, and obligations of the U.S. Government, its agencies and instrumentalities.

The Fund may invest a significant percentage of its net assets in issuers in a single state, territory, or possession, or a small number of states, territories, or possessions. The Fund may at times have significant exposure to one or more industries or sectors.

The Fund may use derivatives, including U.S. Treasury futures, to seek to enhance the Fund’s investment return or for hedging purposes. The Fund is not required to use derivatives in seeking its investment objective or for hedging and might not do so. 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, including reverse repurchase agreement transactions. The Fund may hold a portion of its assets in cash or cash equivalents.

Clinton intends for the Fund’s portfolio dollar-weighted average duration generally to match (within 30%) the average duration of the Bloomberg Municipal 65% High Grade/35% High Yield Index (as of December 31, 2024, the average duration of the Index was 6.32 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. The Fund may invest in securities of any maturity.

Clinton selects the Fund’s investments based on its analysis of opportunities and risks in the business and credit cycle. Clinton manages the Fund’s assets using a dynamic, multi-factor approach that is based on economic, quantitative, market, and credit research and analysis. This research supports Clinton’s overall understanding of portfolio risk. As part of the selection process, Clinton employs a proprietary framework for evaluating issuers based on a variety of criteria. Clinton’s portfolio duration decisions are generally dependent upon (i) a tactical adjustment of portfolio duration, based on interest rate outlook and the level of real yields: current versus historical, inflation expectations, and supply and demand relationships, and (ii) an assessment of value along the current slope of the yield curve, based on quantitative analysis. Clinton then determines the appropriate sector allocation and security selection for the Fund’s portfolio by evaluating credit distribution, relative value, and bond structure. This process focuses on minimizing risk through diversification across the credit spectrum and bond structures, while allowing Clinton to better recognize investment opportunities. 

Principal Risks

Municipal Obligations Risk The amount of public information available about municipal obligations is generally less than for corporate equities or bonds, meaning that the investment performance of municipal obligations may be more dependent on the analytical abilities of the investment adviser than stock or corporate bond investments. The secondary market for municipal obligations also tends to be less well-developed and less liquid than many other securities markets, which may limit the Fund’s ability to sell its municipal obligations at attractive prices. Because many municipal instruments are issued to finance similar projects, conditions in certain industries can significantly affect the Fund and the overall municipal market. The differences between the price at which an obligation can be purchased and the price at which it can be sold may widen during periods of market distress or volatility. Less liquid obligations can become more difficult to value and be subject to erratic price movements. The increased presence of non-traditional participants (such as proprietary trading desks of investment banks and hedge funds) or the absence of traditional participants (such as individuals, insurance companies, banks, and life insurance companies) in the municipal markets may lead to greater volatility in the markets because non-traditional participants may trade more frequently or in greater volume.

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.

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.

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.

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.

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 and Operational Risk The Fund relies on the manager’s investment analysis and its selection of investments to achieve its investment objective, and the Fund is subject to the risk that the manager’s assessment of an investment is wrong. There can be no assurance that the Fund will achieve the intended results and the Fund may incur significant losses. The Fund also runs the risk that deficiencies in the investment adviser’s, subadviser’s, or another service provider’s internal systems or controls will cause losses for the Fund or impair Fund operations.

Reverse Repurchase Agreement Transaction Risk These transactions typically create leverage and subject the Fund to the credit risk of the counterparty.

from the obligation could become subject to regular U.S. federal income tax, possibly retroactively to the date the obligation was issued, the value of the obligation could decline significantly, and all or a portion of the Fund’s distributions to shareholders could be recharacterized as taxable. Some of the Fund’s income distributions may be subject to regular U.S. federal income tax, and distributions of any capital gains generally will be subject to regular U.S. federal income tax. All or a portion of the Fund’s tax-exempt distributions may nevertheless be taken into account for purposes of the U.S. federal alternative minimum tax. In addition, distributions of the Fund’s income and capital gains maybe subject to non-U.S., state, and local taxes.

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.

Performance Information

The Fund began operations on February 1, 2024. Because the Fund is new, there is no table which shows how the Fund’s returns have deviated from the broad market. Performance history for the Fund, along with the performance of the Bloomberg Municipal Bond Index as a primary index and the Bloomberg Municipal 65% High Grade/35% High Yield Index as a secondary index, will be available after the Fund has been in operation for one calendar year.

Investment Adviser: MML Investment Advisers, LLC (“MML Advisers”)

Subadviser(s): Clinton Investment Management, LLC (“Clinton”)

Portfolio Manager(s):

Andrew Clinton is the Chief Executive Officer, Chief Investment Officer, and Lead Portfolio Manager at Clinton. He has managed the Fund since February 2024.

Mark Steffen is a Director and Portfolio Manager at Clinton. He has managed the Fund since February 2024.

Shares of the Fund are generally available through various financial intermediaries, such as retirement plan recordkeepers, broker-dealers, financial institutions, and insurance companies, and to 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).

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*

The Fund reserves the right to change or waive the investment minimums. Class I shares do not have investment minimums and there are no initial or subsequent investment minimums for retirement plans.

​

The Fund intends to distribute income that is exempt from U.S. federal income tax, but may be subject to U.S. federal alternative minimum tax. A portion of the Fund’s distributions may be subject to U.S. federal income tax.

This Fund seeks a high level of current income. Preservation of capital is a secondary goal.

​

(1)

Applies only to certain redemptions of shares bought with no front-end sales charge. Class A shares purchased without a front-end sales charge in accounts aggregating $1 million or more (or accounts aggregating $500,000 or more for holders of Class A shares prior to February 1, 2024) may be subject to a 1.00% contingent deferred sales charge if the shares are tendered and accepted for repurchase within 18 months of purchase. The 18-month period begins on the day on which the purchase is made.

​

(2)

The contingent deferred sales charge on Class C Shares is 1.00% for shares tendered and accepted for repurchase within the first 12 months of purchase. There is no contingent deferred sales charge on Class C Shares thereafter.

​

​

(1)

The expenses in the above table reflect a written agreement by MML Advisers to cap the fees and expenses of the Fund (other than extraordinary legal and other expenses, Acquired Fund Fees and Expenses, interest expense, expenses related to borrowings (with the exception of interest and borrowing expenses related to the Fund’s dedicated line of credit), securities lending, leverage, taxes, and brokerage, short sale dividend and loan expense, or other non-recurring or unusual expenses such as organizational expenses and shareholder meeting expenses, as applicable) through January 31, 2026, to the extent that Total Annual Fund Operating Expenses after Expense Reimbursement would otherwise exceed 0.75%, 0.75%, 1.00%, and 1.75% for Classes I, Y, A, and C, respectively. The Total Annual Fund Operating Expenses after Expense Reimbursement shown in the above table may exceed these amounts, because, as noted in the previous sentence, certain fees and expenses are excluded from the cap. The agreement can only be terminated by mutual consent of the Board of Trustees on behalf of the Fund and MML Advisers.

​

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 front-end 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 actual costs may be higher or lower, based on these assumptions your costs would be:

You would pay the following expenses if you did not redeem your shares:

Portfolio Turnover

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 income-producing floating rate debt securities, consisting of floating rate loans, bonds, and notes, issued primarily by North American and Western European companies. For this purpose, debt instruments issued by issuers based in the Channel Islands, Cayman Islands, and Bermuda are considered North American and Western European companies. Such instruments are primarily, at the time of purchase, rated below investment grade (“junk” or “high yield”) by at least one credit rating agency (below Baa3 by Moody’s Investors Service, Inc. or below BBB- by either S&P Global Ratings, a subsidiary of S&P Global, or Fitch Ratings, Inc.) 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 may invest in a wide range of income-producing floating rate loans, bonds, and notes of issuers based in U.S. and non-U.S. markets, but primarily invests in senior secured loans of North American and Western European corporate issuers that are of below investment grade quality. Under normal market conditions, the Fund allocates its assets among various regions and countries (but in no less than three different countries) and invests at least 40% of its net assets in securities of non-U.S. issuers (or, if less, at least the percentage of net assets that is 5 percentage points less than the percentage of the market-capitalization weighted average of the S&P UBS Leveraged Loan Index and the S&P UBS Western European Leveraged Loan Index, represented by non-U.S. issuers). A significant portion of the Fund’s investments in floating rate debt securities is denominated in a currency other than the U.S. dollar. Although the Fund’s investments in non-U.S. dollar denominated assets may be on a currency hedged or unhedged basis, under normal market conditions, the Fund seeks to hedge substantially all of its exposure to non-U.S. currencies. The Fund may at times have significant exposure to one or more industries or sectors.

The Fund seeks to take advantage of inefficiencies between geographies, primarily the North American and Western European loan and other debt markets. For example, the Fund seeks to take advantage of differences in pricing between senior secured loans of an issuer denominated in U.S. dollars and substantially similar senior secured loans of the same issuer denominated in Euros, potentially allowing the Fund to achieve a higher relative return for the same credit risk exposure.

of Trustees, in an amount at least equal to any payment or delivery obligation of the Fund in connection with such derivative transaction. The Fund’s use of derivatives may consist primarily of total return swaps, options, index swaps or swaps on components of an index, interest rate swaps, credit default swaps, and foreign currency forward contracts and futures. The Fund may hold a portion of its assets in cash or cash equivalents.

The Fund may invest in investments of any duration or maturity.

The Fund may borrow up to one-third of its assets (including the amount borrowed) to fund redemptions, post collateral for hedges, or to purchase loans, bonds, or structured products prior to settlement of pending sale transactions.

Securities may be sold when Barings or BIIL believes they no longer represent relatively attractive investment opportunities.

Principal Risks

leverage. Floating rate notes are generally subject to legal or contractual restrictions on resale, may trade infrequently, and their value may be impaired when the Fund needs to liquidate such securities.

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.

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.

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.

Structured Notes Risk Structured notes and other related instruments purchased by the Fund are generally privately negotiated debt obligations where the principal and/or interest is determined by reference to the performance of a specific asset, benchmark asset, market, or interest rate (“reference measure”). The purchase of structured notes exposes the Fund to the credit risk of the issuer of the structured product. Structured notes may be leveraged, increasing the volatility of a structured note’s value relative to the change in the reference measure. Structured notes may also be less liquid and more difficult to price accurately than less complex securities and instruments or more traditional debt securities.

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.

Covenant Lite Loans Risk Loans in which the Fund invests include covenant lite loans, which may carry more risk to the lender than traditional loans as they may contain fewer restrictive covenants on the borrower than traditionally included in loan documentation or may contain other borrower-friendly characteristics. The Fund may experience relatively greater difficulty or delays in enforcing its rights on its holdings of certain covenant lite loans and debt securities than its holdings of loans or securities with the usual covenants.

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.

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.

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.

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 and Operational Risk The Fund relies on the manager’s investment analysis and its selection of investments to achieve its investment objective, and the Fund is subject to the risk that the manager’s assessment of an investment is wrong. There can be no assurance that the Fund will achieve the intended results and the Fund may incur significant losses. The Fund also runs the risk that deficiencies in the investment adviser’s, subadviser’s, or another service provider’s internal systems or controls will cause losses for the Fund or impair Fund operations.

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.

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 Fund is the successor to the Barings Global Floating Rate Fund (the “Predecessor Fund”), a mutual fund with substantially similar investment objectives, policies, and restrictions, as a result of the reorganization of the Predecessor Fund into the Fund on December 13, 2021. The performance provided in the bar chart and table is that of the Predecessor Fund prior to December 13, 2021, and is that of the Fund after December 13, 2021. The bar chart shows changes in the Fund’s (or Predecessor Fund’s, as applicable) performance from year to year for Class I shares. The table shows how the Fund’s (or Predecessor Fund’s, as applicable) average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance and an additional index that MML Advisers believes more closely reflects the market segments in which the Fund invests (S&P UBS Leveraged Loan Index). Performance for Class A and Class C shares 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/product-performance/​mutual-funds or by calling 1-888-309-3539.

Annual Performance

Class I Shares

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 taxadvantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class I only. After-tax returns for other classes will vary.

Average Annual Total Returns

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(1)

Effective July 24, 2024, the Bloomberg Global Aggregate Index replaced the S&P UBS Leveraged Loan Index as a broad measure of market performance in accordance with new regulatory disclosure requirements. The Fund continues to use the S&P UBS Leveraged Loan Index as a supplemental benchmark that MML Advisers believes more closely reflects the market segments in which the Fund invests.

​

Investment Adviser: MML Investment Advisers, LLC (“MML Advisers”)

Sub-subadviser(s):  Baring International Investment Limited (“BIIL”)

Portfolio Manager(s):

Sean Feeley, CFA is a Managing Director and portfolio manager for Barings’ U.S. High Yield Investments Group. He has managed the Fund since September 2013.

Oliver Harker-Smith is a Managing Director and portfolio manager for Barings’ European High Yield Investments Group. He has managed the Fund since September 2023.

Yield Investments Group. He has managed the Fund since January 2022.

Brian Pacheco, CFA is a Managing Director and portfolio manager for Barings’ U.S. High Yield Investments Group. He has managed the Fund since September 2023.

Chris Sawyer is a Managing Director and the Head of, and a portfolio manager for, Barings’ European High Yield Investments Group. He has managed the Fund since March 2020.

Shares of the Fund are generally available through various financial intermediaries, such as retirement plan recordkeepers, broker-dealers, financial institutions, and insurance companies, and to 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).

​

*

The Fund reserves the right to change or waive the investment minimums. Class I shares do not have investment minimums and there are no initial or subsequent investment minimums for retirement plans.

​

This Fund seeks an absolute return, primarily through current income and secondarily through capital appreciation.

​

(1)

Applies only to certain redemptions of shares bought with no front-end sales charge. Class A shares purchased without a front-end sales charge in accounts aggregating $1 million or more (or accounts aggregating $500,000 or more for holders of Class A shares prior to February 1, 2024) may be subject to a 1.00% contingent deferred sales charge if the shares are tendered and accepted for repurchase within 18 months of purchase. The 18-month period begins on the day on which the purchase is made.

​

(2)

The contingent deferred sales charge on Class C Shares is 1.00% for shares tendered and accepted for repurchase within the first 12 months of purchase. There is no contingent deferred sales charge on Class C Shares thereafter.

​

​

(1)

The expenses in the above table reflect a written agreement by MML Advisers to cap the fees and expenses of the Fund (other than extraordinary legal and other expenses, Acquired Fund Fees and Expenses, interest expense, expenses related to borrowings (with the exception of interest and borrowing expenses related to the Fund’s dedicated line of credit), securities lending, leverage, taxes, and brokerage, short sale dividend and loan expense, or other non-recurring or unusual expenses such as organizational expenses and shareholder meeting expenses, as applicable) through January 31, 2026, to the extent that Total Annual Fund Operating Expenses after Expense Reimbursement would otherwise exceed 0.85%, 0.90%, 1.16%, and 1.95% for Classes I, Y, A, and C, respectively. The Total Annual Fund Operating Expenses after Expense Reimbursement shown in the above table may exceed these amounts, because, as noted in the previous sentence, certain fees and expenses are excluded from the cap. The agreement can only be terminated by mutual consent of the Board of Trustees on behalf of the Fund and MML Advisers.

​

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 front-end 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 actual costs may be higher or lower, based on these assumptions your costs would be:

You would pay the following expenses if you did not redeem your shares:

Portfolio Turnover

Principal Investment Strategies

The Fund may invest in investments of any duration or maturity.

The Fund may borrow up to one-third of its assets (including the amount borrowed) to fund redemptions, post collateral for hedges, or to purchase loans, bonds, or structured products prior to settlement of pending sale transactions.

Securities may be sold when Barings or BIIL believes they no longer represent relatively attractive investment opportunities.

Principal Risks

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.

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.

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.

the outcome of any such litigation could significantly impact the value of the Fund’s mortgage-backed investments.

Structured Notes Risk Structured notes and other related instruments purchased by the Fund are generally privately negotiated debt obligations where the principal and/or interest is determined by reference to the performance of a specific asset, benchmark asset, market, or interest rate (“reference measure”). The purchase of structured notes exposes the Fund to the credit risk of the issuer of the structured product. Structured notes may be leveraged, increasing the volatility of a structured note’s value relative to the change in the reference measure. Structured notes may also be less liquid and more difficult to price accurately than less complex securities and instruments or more traditional debt securities.

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.

Covenant Lite Loans Risk Loans in which the Fund invests include covenant lite loans, which may carry more risk to the lender than traditional loans as they may contain fewer restrictive covenants on the borrower than traditionally included in loan documentation or may contain other borrower-friendly characteristics. The Fund may experience relatively greater difficulty or delays in enforcing its rights on its holdings of certain covenant lite loans and debt securities than its holdings of loans or securities with the usual covenants.

the Fund is invested in distressed securities, its ability to achieve current income for its shareholders may be diminished.

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.

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.

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 and Operational Risk The Fund relies on the manager’s investment analysis and its selection of investments to achieve its investment objective, and the Fund is subject to the risk that the manager’s assessment of an investment is wrong. There can be no assurance that the Fund will achieve the intended results and the Fund may incur significant losses. The Fund also runs the risk that deficiencies in the investment adviser’s, subadviser’s, or another service provider’s internal systems or controls will cause losses for the Fund or impair Fund operations.

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.

may be highly illiquid and their values may experience significant volatility. Restricted securities may be difficult to value.

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 Fund is the successor to the Barings Global Credit Income Opportunities Fund (the “Predecessor Fund”), a mutual fund with substantially similar investment objectives, policies, and restrictions, as a result of the reorganization of the Predecessor Fund into the Fund on December 13, 2021. The performance provided in the bar chart and table is that of the Predecessor Fund prior to December 13, 2021, and is that of the Fund after December 13, 2021. The bar chart shows changes in the Fund’s (or Predecessor Fund’s, as applicable) performance from year to year for Class I shares. The table shows how the Fund’s (or Predecessor Fund’s, as applicable) average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance and an additional index that MML Advisers believes more closely reflects the market segments in which the Fund invests (FTSE 3 Month US T Bill Index +500 bps). Performance for Class A and Class C shares 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/product-performance/​mutual-funds or by calling 1-888-309-3539.

Annual Performance

Class I Shares

those shown. After-tax returns are not relevant to investors who hold Fund shares through taxadvantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class I only. After-tax returns for other classes will vary.

Average Annual Total Returns

​

(1)

Effective July 24, 2024, the Bloomberg Global Aggregate Index replaced the Bloomberg Multiverse Index as a broad measure of market performance in accordance with new regulatory disclosure requirements.

​

Investment Adviser: MML Investment Advisers, LLC (“MML Advisers”)

Sub-subadviser(s):  Baring International Investment Limited (“BIIL”)

Portfolio Manager(s):

Chris Ellis is a Managing Director and a portfolio manager for Barings’ European High Yield Investments Group. He has managed the Fund since September 2023.

Sean Feeley, CFA is a Managing Director and portfolio manager for Barings’ U.S. High Yield Investments Group. He has managed the Fund since September 2013.

Omotunde Lawal, CFA is a Managing Director and the Head of, and a portfolio manager for, Barings’ Emerging Markets Corporate Debt and EMEA Corporate Credit Groups. She has managed the Fund since May 2021.

Brian Pacheco, CFA is a Managing Director and portfolio manager for Barings’ U.S. High Yield Investments Group. He has managed the Fund since February 2023.

Scott Roth, CFA is a Managing Director and the Head of, and a portfolio manager for, Barings’ Global High Yield Group. He has managed the Fund since September 2013.

Chris Sawyer is a Managing Director and the Head of, and a portfolio manager for, Barings’ European High Yield Investments Group. He has managed the Fund since May 2021.

Shares of the Fund are generally available through various financial intermediaries, such as retirement plan recordkeepers, broker-dealers, financial institutions, and insurance companies, and to 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).

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*

The Fund reserves the right to change or waive the investment minimums. Class I shares do not have investment minimums and there are no initial or subsequent investment minimums for retirement plans.

​

This Fund seeks to achieve maximum total return, consistent with preservation of capital and prudent investment management, through high current income generation and, where appropriate, capital appreciation.

​

(1)

Applies only to certain redemptions of shares bought with no front-end sales charge. Class A shares purchased without a front-end sales charge in accounts aggregating $1 million or more (or accounts aggregating $500,000 or more for holders of Class A shares prior to February 1, 2024) may be subject to a 1.00% contingent deferred sales charge if the shares are tendered and accepted for repurchase within 18 months of purchase. The 18-month period begins on the day on which the purchase is made.

​

(2)

The contingent deferred sales charge on Class C Shares is 1.00% for shares tendered and accepted for repurchase within the first 12 months of purchase. There is no contingent deferred sales charge on Class C Shares thereafter.

​

​

(1)

The expenses in the above table reflect a written agreement by MML Advisers to cap the fees and expenses of the Fund (other than extraordinary legal and other expenses, Acquired Fund Fees and Expenses, interest expense, expenses related to borrowings, securities lending, leverage, taxes, and brokerage, short sale dividend and loan expense, or other non-recurring or unusual expenses such as organizational expenses and shareholder meeting expenses, as applicable) through January 31, 2026, to the extent that Total Annual Fund Operating Expenses after Expense Reimbursement would otherwise exceed 0.89%, 0.95%, 1.16%, and 1.89% for Classes I, Y, A, and C, respectively. The Total Annual Fund Operating Expenses after Expense Reimbursement shown in the above table may exceed these amounts, because, as noted in the previous sentence, certain fees and expenses are excluded from the cap. The agreement can only be terminated by mutual consent of the Board of Trustees on behalf of the Fund and MML Advisers.

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Example

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 front-end 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 actual costs may be higher or lower, based on these assumptions your costs would be:

You would pay the following expenses if you did not redeem your shares:

Portfolio Turnover

Principal Investment Strategies

Fund focuses its investments in Asia, Africa, the Middle East, Latin America, and the developing countries of Europe. 

The Fund will invest in debt instruments of all types, including bonds, notes, U.S. and Group of Ten (commonly referred to as “G10”) country treasury obligations, sovereign issues, covered bonds, commercial paper, and other fixed and floating rate income securities and are either secured or unsecured, and either senior or subordinated. To a limited extent, the Fund may invest in (i) securities that are convertible into equity securities, (ii) equity securities (including warrants and common stock), (iii) certificates of deposit, (iv) bankers’ acceptances, and (v) loan participations and loan assignments which are un-securitized. Although the Fund’s investment in non-U.S. dollar denominated assets may be on a currency hedged or unhedged basis, under normal market conditions, the Fund seeks to hedge substantially all of its exposure to non-U.S. currencies. 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. 

The Fund expects to achieve certain exposures primarily through derivative transactions, including without limitation, forward foreign currency exchange contracts; futures on securities, indexes, currencies, commodities, swaps, and other investments; options; and interest rate swaps, crosscurrency swaps, total return swaps, and credit default swaps, which may create economic leverage in the Fund. The Fund may engage in derivative transactions to enhance total return, to seek to hedge against fluctuations in securities prices, interest rates, or currency exchange rates, to change the effective duration of its portfolio, to manage certain investment risks, and/or as a substitute for the purchase or sale of securities, currencies, or commodities. Derivatives instruments that provide exposure to debt securities that are economically tied to emerging market countries or to a country the Fund’s subadviser, Barings LLC (“Barings”), or sub-subadviser, Baring International Investment Limited (“BIIL”) considers to be equivalent to such countries or have economic characteristics similar to such investments may be used to satisfy the Fund’s 80% policy.

Investors Service, Inc. (“Moody’s) or BBBor higher by either S&P Global Ratings, a subsidiary of S&P Global (“S&P”), or Fitch Ratings, Inc. (“Fitch”), or, if unrated, determined to be of comparable quality by Barings or BIIL. Below investment grade debt securities are rated below Baa3 by Moody’s and BBB- by S&P and Fitch or, if unrated, determined by Barings or BIIL to be of comparable quality.

Principal Risks

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.

geopolitical, public health, and other conditions than the U.S. market.

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.

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.

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.

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.

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.

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 and Operational Risk The Fund relies on the manager’s investment analysis and its selection of investments to achieve its investment objective, and the Fund is subject to the risk that the manager’s assessment of an investment is wrong. There can be no assurance that the Fund will achieve the intended results and the Fund may incur significant losses. The Fund also runs the risk that deficiencies in the investment adviser’s, subadviser’s, or another service provider’s internal systems or controls will cause losses for the Fund or impair Fund operations.

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.

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.

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 Fund is the successor to the Barings Emerging Markets Debt Blended Total Return Fund (the “Predecessor Fund”), a mutual fund with substantially similar investment objectives, policies, and restrictions, as a result of the reorganization of the Predecessor Fund into the Fund on December 13, 2021. The performance provided in the bar chart and table is that of the Predecessor Fund prior to December 13, 2021, and is that of the Fund after December 13, 2021. The bar chart shows changes in the Fund’s (or Predecessor Fund’s, as applicable) performance from year to year for Class I shares. The table shows how the Fund’s (or Predecessor Fund’s, as applicable) average annual returns for 1 and 5 years, and since inception, compare with those of a broad measure of market performance. Performance for Class A and Class C shares 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/product-performance/​mutual-funds or by calling 1-888-309-3539.

Annual Performance

Class I Shares

an investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold Fund shares through taxadvantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class I only. After-tax returns for other classes will vary.

Average Annual Total Returns

Investment Adviser: MML Investment Advisers, LLC (“MML Advisers”)

Sub-subadviser(s):  Baring International Investment Limited (“BIIL”)

Portfolio Manager(s):

Ricardo Adrogué is a Managing Director and the Head of, and a portfolio manager for, Barings’ Global Sovereign Debt and Currencies Group. He has managed the Fund since October 2015.

Barings’ Emerging Markets Sovereign Debt Group. He has managed the Fund since October 2015.

Natalia Krol is a Managing Director and portfolio manager for Barings’ Emerging Markets Blended Total Return strategies. She has managed the Fund since August 2018.

Shares of the Fund are generally available through various financial intermediaries, such as retirement plan recordkeepers, broker-dealers, financial institutions, and insurance companies, and to 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).

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*

The Fund reserves the right to change or waive the investment minimums. Class I shares do not have investment minimums and there are no initial or subsequent investment minimums for retirement plans.

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Changes to Investment Objectives and Strategies. 

Note Regarding Percentage Limitations. 

Credit Ratings. 

same rating as a security determined by the investment adviser or subadviser to be of comparable quality. Unless otherwise stated, if a security is rated by more than one nationally recognized statistical rating organization, the highest rating is used. The Fund may retain any security whose rating has been downgraded after purchase.

Duration. 

Duration is a measure of the expected life of a debt security that is used to determine the sensitivity of the security’s value to changes in interest rates. The longer a security’s duration, the more sensitive it will be to changes in interest rates. For example, if interest rates rise by 1%, the value of a debt security with a duration of two years would be expected to decline 2% and the value of a debt security with a duration of four years would be expected to decline 4%. Unlike the maturity of a debt security, which measures only the time until final payment is due, duration takes into account the time until all payments of interest and principal on a security are expected to be made, including how these payments are affected by prepayments and by changes in interest rates. Determining duration may involve estimates of future economic parameters, which may vary from actual future values.

Leverage. 

Temporary Defensive Positions. 

Portfolio Turnover. 

Non-Principal Investments; Use of Derivatives; Securities Loans; Repurchase Agreements. 

respect to a particular index, security, or currency, it will lose money if the index, security, or currency appreciates in value, or an expected credit or other event that might affect the value of the index, security, or currency fails to occur. Losses could be significant. Derivatives transactions may include, but are not limited to, foreign currency exchange transactions, options, futures contracts, interest rate swaps, interest rate futures contracts, forward contracts, total return swaps, credit default swaps, and hybrid instruments. A Fund may use derivatives to create investment leverage. See “Additional Information Regarding Principal Risks,” below, and the SAI for more information regarding those transactions.

Foreign Securities. 

“European securities,” “Latin American securities,” “Asian securities,” or “emerging markets” ​(or similar directions) or (b) at least some percentage of the Fund’s assets in foreign securities, etc., the Fund will take the view that a security meets this description so long as the issuer of a security is tied economically to the particular country or geographic region indicated by words of the relevant investment objective and/or strategy (the “Relevant Language”). For these purposes the issuer of a security is deemed to have that tie if:

In addition, the Funds intend to treat derivative securities (e.g., call options) for this purpose by reference to the underlying security. Conversely, if the investment objective and/or strategy of a Fund limits the percentage of assets that may be invested in “foreign securities,” etc. or prohibits such investments altogether, a Fund intends to categorize securities as “foreign,” etc. only if the security possesses all of the attributes described above in clauses (i), (ii), and (iii).

Disclosure of Portfolio Holdings​

Additional Information Regarding Principal Risks​

•

Bank Loans Risk 

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instruments and may lead to defaults. The value of any collateral securing a bank loan may decline after a Fund invests, and there is a risk that the value of the collateral may not be sufficient to cover the amount owed to the Fund. In addition, collateral securing a loan may be found invalid, may be used to pay other outstanding obligations of the borrower under applicable law, or may be difficult to sell. In the event that a borrower defaults, a Fund’s access to the collateral may be limited by bankruptcy and other insolvency laws. There is also the risk that the collateral may be difficult to liquidate, or that a majority of the collateral may be illiquid. In addition, some loans may be unsecured. Unsecured loans generally present a greater risk of loss to the Fund if the issuer defaults. In some cases, the Fund may rely on a third party to administer its interest in a loan, and so is subject to the risk that the third party will be unwilling or unable to perform its obligations. The Fund may invest in a loan by purchasing an indirect interest in the loan held by a third party. In that case, the Fund will be subject to both the credit risk of the borrower and of the third party, and the Fund may be unable to realize some or all of the value of its interest in the loan in the event of the insolvency of the third party. 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 bank loans may be illiquid, and bank loans generally tend to be less liquid than many other debt securities. The lack of a liquid secondary market may make it more difficult for the Fund to assign a value to such instruments for purposes of valuing the Fund’s portfolio and calculating its net asset value (“NAV”). 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 

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•

Cash Position Risk 

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•

Convertible Securities Risk 

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•

Covenant Lite Loans Risk 

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Loans in which a Fund invests include covenant lite loans, which may carry more risk to the lender than traditional loans as they may contain fewer restrictive covenants on the borrower than traditionally included in loan documentation or may contain other borrower-friendly characteristics. A Fund may experience relatively greater difficulty or delays in enforcing its rights on its holdings of certain covenant lite loans and debt securities than its holdings of loans or securities with the usual covenants.

•

Credit Risk 

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•

Currency Risk 

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•

Cyber Security and Technology Risk 

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•

Defaulted and Distressed Securities Risk 

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Defaulted securities risk refers to the uncertainty of repayment of defaulted securities and obligations of distressed issuers. 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 subject to significant uncertainties. The market will likely be less liquid for distressed or defaulted securities than for other types of securities. Reduced liquidity can affect the valuations of distressed or defaulted securities, make their valuation and sale more difficult, and result in greater volatility. Insolvency laws and practices in foreign countries are different than those in the U.S. and the effect of these laws and practices cannot be predicted with certainty. Investments in defaulted securities and obligations of distressed issuers are considered speculative. To the extent a Fund is invested in distressed securities, its ability to achieve current income for its shareholders may be diminished.

•

Derivatives Risk 

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•

Emerging Markets Risk 

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•

Equity Securities Risk 

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•

Fixed Income Securities Risk 

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•

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may lock in a below-market interest rate, increase the security’s duration, and reduce the value of the security.

•

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.

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Interest Rate Risk. The values of bonds and other debt instruments usually rise and fall in response to changes in interest rates. The values of debt instruments generally increase in response to declines in interest rates and decrease in response to rises in interest rates. Interest rates can also change in response to the supply and demand for credit, government and/or central bank monetary policy and action, inflation rates, and other factors. Interest rate risk is generally greater for fixed-rate instruments than floating-rate instruments and for investments with longer durations or maturities. Some investments give the issuer the option to call or redeem an investment before its maturity date. If an issuer calls or redeems an investment during a time of declining interest rates, a Fund might have to reinvest the proceeds in an investment offering a lower yield, and therefore might not benefit from any increase in value as a result of declining interest rates. Negative or very low interest rates could magnify the risks associated with changes in interest rates. In general, changing interest rates, including rates that fall below zero, could have unpredictable effects on markets and may expose fixed income and related markets to heightened levels of interest rate volatility and liquidity risk. Potential future changes in government and/or central bank monetary policy and action may also affect the level of interest rates. Monetary policy measures have in the past, and may in the future, exacerbate risks associated with rising interest rates.

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Foreign Investment Risk 

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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. Sanctions, or the threat of sanctions, may cause volatility in regional and global markets and may negatively impact the performance of various sectors and industries, as well as companies in other countries, which could have a negative effect on the performance of a Fund. Economic or other sanctions imposed on a foreign country or issuer by the U.S., or on the U.S. by a foreign country, could impair a Fund’s ability to buy, sell, hold, receive, deliver, or otherwise transact in certain securities. In the event of nationalization, expropriation, confiscation, or other government action, intervention, or restriction, a Fund could lose its entire investment in a particular foreign issuer or country. Civil unrest, geopolitical tensions, armed conflicts, wars, and acts of terrorism are other potential risks that could adversely affect an investment in a foreign security or in foreign markets or issuers generally. There may be quotas or other limits on the ability of a Fund (or clients of a 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 a 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.

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Hedging Risk 

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There can be no assurance that a Fund’s hedging transactions will be effective. If a Fund takes a short position in a particular currency, security, or bond market, it will lose money if the currency, security, or bond market appreciates in value, or an expected credit event fails to occur. Any efforts at buying or selling currencies could result in significant losses for the Fund. Further, foreign currency transactions that are intended to hedge the currency risk associated with investing in foreign securities and minimize the risk of loss that would result from a decline in the value of the hedged currency may also limit any potential gain that might result should the value of such currency increase.

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Inflation Risk 

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Leveraging Risk 

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Liquidity Risk 

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Market values for illiquid securities may not be readily available, and there can be no assurance that any fair value assigned to an illiquid security at any time will accurately reflect the price a Fund might receive upon the sale of that security. It is possible that, during periods of extreme market volatility or unusually high and unanticipated levels of redemptions or in the case of a liquidation of a Fund, a Fund may be forced to sell large amounts of securities or terminate outstanding transactions at a price or time that is not advantageous in order to meet redemptions or other cash needs or to pay liquidation proceeds. In such a case, the sale proceeds received by a Fund may be substantially less than if the Fund had been able to sell the securities or terminate the transactions in more orderly transactions, and the sale price may be substantially lower than the price previously used by the Fund to value the securities for purposes of determining the Fund’s NAV. To the extent a Fund holds illiquid securities, it may be more likely to pay redemption proceeds in kind.

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Management and Operational Risk 

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overall investment performance of the Fund. There can be no assurance that there will be a liquid market for instruments held by the Fund at any time. The Funds are also subject to operational risks resulting from other services provided by a Fund’s investment adviser, subadviser, and other service providers, including pricing, administrative, accounting, tax, legal, custody, transfer agency, and other operational services. Examples of such operational risks include the possibility of loss caused by inadequate procedures and controls, human error, and system failures by a service provider. For example, trading delays or errors could prevent a Fund from benefiting from investment gains or avoiding losses. In addition, a service provider may be unable to provide an NAV for a Fund or share class on a timely basis. Additionally, legislative, regulatory, or tax developments may adversely affect management of a Fund and, therefore, the ability of the Fund to achieve its investment objective.

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Market Risk 

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outbreaks, epidemics, or pandemics, may have a significant adverse effect on a Fund’s performance and have the potential to impair the ability of a Fund’s investment adviser, subadviser, or other service providers to serve the Fund and could lead to disruptions that negatively impact the Fund. Different parts of the market and different types of securities can react differently to these conditions. The possibility that security prices in general will decline over short or even extended periods subjects a Fund to unpredictable declines in the value of its shares, as well as potentially extended periods of poor performance. In addition, the increasing popularity of passive index-based investing may have the potential to increase security price correlations and volatility. As passive strategies generally buy or sell securities based simply on inclusion and representation in an index, securities’ prices will have an increasing tendency to rise or fall based on whether money is flowing into or out of passive strategies rather than based on an analysis of the prospects and valuation of individual securities. This may result in increased market volatility as more money is invested through passive strategies.

In addition, military action by Russia in Ukraine could adversely affect global energy and financial markets, including through global supply chain disruptions, increased inflationary pressures, and reduced economic activity, and therefore could affect the value of a Fund’s investments, including beyond the Fund’s direct exposure to Russian issuers or nearby geographic regions. The extent and duration of the military action, sanctions, or the threat of sanctions (including any Russian retaliatory responses to such sanctions), and resulting market disruptions are impossible to predict and could be substantial. Other issuers or markets could be similarly affected by past or future geopolitical or other events or conditions.

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Mortgage- and Asset-Backed Securities Risk 

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generally increase, including as a result of the effects of those conditions on commercial real estate markets, the ability of commercial tenants to make loan payments, and the ability of a property to attract and retain commercial tenants. Additionally, certain types of real estate may be adversely affected by changing usage trends, such as office buildings as a result of work-from-home practices and commercial facilities as a result of an increase in online shopping, which could in turn result in defaults and declines in value of mortgage-backed securities secured by such properties.

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Municipal Obligations Risk 

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Preferred Stock Risk 

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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.

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Redemptions by Affiliated Funds and by Other Significant Investors 

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Reinvestment Risk 

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Repurchase Agreement Risk 

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Restricted Securities Risk 

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Reverse Repurchase Agreement Transaction Risk 

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In a reverse repurchase agreement transaction, a Fund sells securities to a bank or securities dealer and agrees to repurchase them at an agreed time and price; a reverse repurchase agreement is similar to a secured borrowing by a Fund. These types of transactions generally create leverage (see “Leveraging Risk” above). It may be difficult or impossible for a Fund to exercise its rights under a reverse repurchase agreement in the event of the insolvency or bankruptcy of the counterparty, and the Fund may not be able to purchase the securities or other assets subject to the transaction and may be required to return any collateral it holds.

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Risk of Investment in other Funds or Pools 

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protections against certain conflicts of interest, and custodial risks). A Fund is exposed indirectly to all of the risks applicable to any other investment company or pool in which it invests, including that the investment company or pool will not perform as expected. Investments in other investment companies or private pools may be illiquid, may be leveraged, and may be highly volatile.

Investing in other investment companies or private investment vehicles sponsored or managed by the investment adviser or subadviser, as applicable, or affiliates of the investment adviser or subadviser, as applicable, involves potential conflicts of interest. For example, the investment adviser or subadviser, as applicable, or their affiliates may receive fees based on the amount of assets invested in such other investment vehicles, which fees may be higher than the fees the investment adviser or subadviser, as applicable, receives for managing the investing Fund. Investment by a Fund in those other vehicles may be beneficial in the management of those other vehicles, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the investment adviser or subadviser, as applicable, will have an incentive to invest a portion of a Fund’s assets in investment vehicles sponsored or managed by the investment adviser or subadviser, as applicable, or their affiliates in lieu of investments by the Fund directly in portfolio securities, and will have an incentive to invest in such investment vehicles over non-affiliated investment companies. The investment adviser or subadviser, as applicable, will have no obligation to select the least expensive or best performing funds available to serve as an underlying investment vehicle. Similarly, the investment adviser or subadviser, as applicable, will have an incentive to delay or decide against the sale of interests held by the Fund in investment vehicles sponsored or managed by the investment adviser or subadviser, as applicable, or their affiliates.

market price of an ETF’s shares may trade above or below its NAV, the risk that an active trading market for an ETF’s shares may not develop or be maintained, the risk that trading of an ETF’s shares may be halted, and the risk that the ETF’s shares may be delisted from the listing exchange. A Fund will generally purchase and sell shares of ETFs in the secondary market and will be subject to these secondary market trading risks. Some ETFs engage in derivatives strategies and use leverage, and as a result their values can be highly volatile. It is possible that an ETF’s performance will diverge from the performance of any index or indexes it seeks to replicate. Because shares of ETFs may be actively traded, their values may be affected in unanticipated ways by the effects of supply and demand in the market for shares of ETFs, activities of short sellers, or unusual speculative activity in their shares. Some ETFs may experience periods of reduced liquidity due to restrictions on trading activity or due to a general lack of investor interest in the asset class represented by the ETF. Unlike shares of a mutual fund, which can be bought and redeemed from the issuing fund by all shareholders at a price based on NAV, shares of an ETF may be purchased or redeemed directly from the ETF solely by Authorized Participants (“APs”) and only in aggregations of a specified number of shares (“Creation Units”). In addition, shares of ETFs may be purchased and sold in the secondary market at prevailing market prices. ETFs may have a limited number of financial institutions that act as APs. To the extent that those APs exit the business, or are unable to or choose not to process creation and/or redemption orders for Creation Units, and no other AP steps forward to create and redeem ETF shares, the ETF’s shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting. When a Fund buys or sells ETF shares on an exchange, it may incur certain costs, including brokerage commissions, the “bid-ask spread,” and other charges.

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Sector Risk 

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Sovereign Debt Obligations Risk 

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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. A governmental entity’s willingness or ability to pay interest and repay principal in a timely manner may be affected by a variety of factors, including its cash flow, the size of its reserves, its access to foreign exchange, the relative size of its debt service burden to its economy as a whole, and political constraints. A governmental entity may default on its obligations or may require renegotiation or rescheduling of debt payments. 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. The sovereign debt of many non-U.S. governments, including their sub-divisions and instrumentalities, is rated below investment grade (“junk” or “high yield” bonds). Sovereign debt risk may be greater for debt securities issued or guaranteed by emerging and/or frontier market countries. At times, certain emerging and frontier market countries have declared moratoria on the payment of principal and interest on external debt. Certain emerging and frontier market countries have experienced difficulty in servicing their sovereign debt on a timely basis, which has led to defaults and the restructuring of certain indebtedness to the detriment of debtholders.

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Structured Notes Risk 

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Tax-Sensitive Investing Risk 

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Certain Funds may hold or sell a security in order to achieve more favorable tax-treatment. A Fund’s utilization of various tax-management techniques may be curtailed or eliminated by tax legislation, regulation, or interpretations. Additionally, a Fund’s intention to qualify and be eligible for treatment as a regulated investment company can limit its ability to implement such techniques or can require it to engage in transactions in which it would otherwise not engage, resulting in additional transaction costs and reducing the Fund’s return to shareholders. A Fund may not be able to minimize taxable distributions to shareholders and a portion of the Fund’s distributions may be taxable.

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Tax Risk 

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obligation. If there is a determination that an issuer of a tax-exempt municipal obligation has not complied with applicable requirements, interest from the obligation could become subject to regular U.S. federal income tax, possibly retroactively to the date the obligation was issued, the value of the obligation could decline significantly, and all or a portion of a Fund’s distributions to shareholders could be recharacterized as taxable. Some of a Fund’s income distributions may be subject to regular U.S. federal income tax, and distributions of any capital gains generally will be subject to regular U.S. federal income tax. All or a portion of a Fund’s tax-exempt distributions may nevertheless be taken into account for purposes of the U.S. federal alternative minimum tax. In addition, distributions of a Fund’s income and capital gains maybe subject to non-U.S., state, and local taxes.

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U.S. Government Securities Risk 

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U.S. Municipal Project-Specific Risk 

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Valuation Risk 

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Variable and Floating Rate Securities Risk 

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Variable or floating rate securities are debt securities with variable or floating interest rates payments. Variable or floating rate securities bear rates of interest that are adjusted periodically according to formulae intended generally to reflect market rates of interest and allow a Fund to participate (determined in accordance with the terms of the securities) in increases in interest rates through upward adjustments of the coupon rates on the securities. However, during periods of increasing interest rates, changes in the coupon rates may lag behind the changes in market rates or may have limits on the maximum increases in coupon rates. Alternatively, during periods of declining interest rates, the coupon rates on such securities will typically readjust downward resulting in a lower yield.

rates vary inversely with market rates of interest, or range floaters or capped floaters, whose rates are subject to periodic or lifetime caps, or in securities that pay a rate of interest determined by applying a multiple to the variable rate involves special risks as compared to investment in a fixed-rate security and may involve leverage. The extent of increases and decreases in the values of derivative variable rate securities and the corresponding change to the NAV of a Fund in response to changes in market rates of interest generally may be larger than comparable changes in the value of an equal principal amount of a fixed-rate security having similar credit quality, redemption provisions, and maturity. The markets for such securities may be less developed and may have less liquidity than the markets for conventional securities.

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When-Issued, Delayed Delivery, TBA, and Forward Commitment Transaction Risk 

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A Fund may purchase securities on a when-issued, delayed delivery, to-be-announced, or forward commitment basis. These transactions involve a commitment by a Fund to purchase securities for a predetermined price or yield, with payments and delivery taking place more than seven days in the future, or after a period longer than the customary settlement period for that type of security. These transactions involve a risk of loss if the value of the securities declines prior to the settlement date. These transactions may create investment leverage. Recently effective rules of the Financial Industry Regulatory Authority impose mandatory margin requirements for certain types of when-issued, TBA, or forward commitment transactions, with limited exceptions. Mandatory collateralization could increase the cost of such transactions and impose added operational complexity and may increase the credit risk of such transactions to a Fund.

Choosing a Share Class.

The only differences among the various classes are that (a) each class is subject to different expenses specific to that class, including any expenses under a Rule 12b-1 Plan and administrative and shareholder service expenses; (b) each class has a different class designation; (c) each class has exclusive voting rights with respect to matters solely affecting such class; and (d) each class has different exchange privileges. Not all of the classes of a Fund are available in every state.

Determining which share class is best for you depends on the dollar amount you are investing and the number of years for which you are willing to invest. Based on your personal situation, your financial intermediary can help you decide which class of shares makes the most sense for you. A financial intermediary is entitled to receive compensation for purchases made through the financial intermediary. The Funds, the transfer agent, and MML Distributors, LLC (the “Distributor”) do not provide investment advice.

Investors may receive different levels of service in connection with investments in different classes of shares, and intermediaries may receive different levels of compensation in connection with selling different classes of shares. For additional information, call us toll free at 1-888-309-3539 or contact a sales representative or financial intermediary who offers the classes.

Fees and Expenses.

Different classes of shares are subject to different fees and expenses. A class’s fees and expenses will affect the performance of that class.

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Administrative and Shareholder Services Fee: Shares of all classes, except Class I shares, are subject to an administrative and shareholder services fee. This fee is described above under “Management of the Funds – Investment Adviser.”

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Plan, Shareholder Servicing, and Payments to Intermediaries.”

Purchasing Shares.

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Financial Intermediaries: Class I shares are offered primarily through various financial intermediaries, such as retirement plan recordkeepers, broker-dealers, financial institutions, and insurance companies.

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Class Y shares are available through advisory or fee-based programs sponsored by a broker-dealer, financial institution, or other financial intermediary. Class I shares may also be made available through such advisory programs whose sponsor has entered into a written agreement with the Distributor or MML Advisers.

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Investment Accounts and Plans: Class I and Class A shares are available for purchase by insurance company separate investment accounts, qualified plans under Sections 401(a) and 401(k) of the Code, Code Section 403(b) and 457 plans, Code Section 501(c)(9 ) associations, non-qualified deferred compensation plans, and other institutional investors, including, but not limited to, endowments and foundations.

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Funds: Class I shares are available for purchase by mutual funds and collective trust funds.

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A plan or institutional investor will be permitted to purchase Class I or Class A shares based upon the expected size (over time), servicing needs, or distribution or servicing costs for the plan or institutional investor as determined by the Distributor or a financial intermediary, as applicable.

A financial intermediary may, by agreement with the Distributor or MML Advisers, make available to its plan or institutional clients or its advisory or fee-based program participants shares of one class or a limited number of classes of the Funds. An investor should consult its financial intermediary for information (including expense information) regarding the share class(es) the intermediary will make available for purchase by the investor.

At the discretion of the Distributor or MML Advisers, a shareholder who held shares of a Fund prior to February 1, 2024 may continue to be eligible to buy the same share class of the Fund even if such shareholder no longer satisfies the requirements above.

Additional Information Regarding the Classes of Shares. 

Present and former officers, directors, trustees, and employees (and their eligible family members) of each Fund, MassMutual and its affiliates, and retirement accounts established for the benefit of such individuals, are permitted to purchase Class Y and Class A shares of each Fund.

Purchases of Class Y shares require an initial minimum investment of $100,000 and a subsequent minimum investment of $250; and purchases of Class A and Class C shares require an initial minimum investment of $1,000 and a subsequent minimum investment of $250. Class I shares do not have investment minimums and there are no initial or subsequent investment minimums for retirement plans. Purchases of $500,000 or more cannot be made in Class C shares.

Class Y shares are sold at the NAV per share without a sales charge through financial intermediaries that have agreements with MML Advisers or its affiliates or the Distributor for that purpose. A financial intermediary that buys Class Y shares for its customers’ accounts may impose charges on those accounts. The procedures for buying, selling, exchanging, and transferring a Fund’s other classes of shares (other than the time those orders must be received by the transfer agent) and some of the special account features available to investors buying other classes of shares do not apply to Class Y shares. Instructions for buying, selling, exchanging, or transferring Class Y shares must be submitted by a financial intermediary, not by its customers for whose benefit the shares are held.

Class I shares are sold at the NAV per share without a sales charge. An institutional investor that buys Class I shares for its customers’ accounts may impose charges on those accounts. The procedures for buying, selling, exchanging, and transferring each Fund’s other classes of shares (other than the time those orders must be received by the transfer agent), and most of the special account features available to investors buying other classes of shares, do not apply to Class I shares.

Class A Shares

Front-end Sales Charges

Class A shares are sold at their offering price, which is normally NAV plus a front-end sales charge. However, in some cases, as described below, purchases are not subject to a front-end sales charge, and the offering price will be the NAV. In other cases, reduced front-end sales charges may be available, as described below. Out of the amount you invest, the Fund receives the NAV to invest for your account.

The front-end sales charge varies depending on the amount of your purchase. Shares you purchase with reinvested dividends or other distributions are not subject to a front-end sales charge. A portion of the front-end sales charge may be retained by the Distributor or allocated to your dealer as a concession. The Distributor reserves the right to reallow the entire front-end sales charge as a concession to dealers. The current front-end sales charge rates and concessions paid to dealers and brokers are as follows:

Front-End Sales Charge (As a Percentage of Offering Price)/ Front-End Sales Charge (As a Percentage of Net Amount Invested)/ Concession (As a Percentage of Offering Price) for Different Purchase Amounts:

Contingent Deferred Sales Charges for Class A Shares

There is no front-end sales charge on purchases of Class A shares of any one or more of the Funds aggregating $250,000 or more or $1 million or more (or $500,000 or more for holders of Class A shares of the Global Floating Rate Fund, Global Credit Income Opportunities Fund, and Emerging Markets Debt Blended Total Return Fund prior to February 1, 2024) and the Distributor pays dealers of record concessions in an amount equal to 1.00% or 0.50% of these purchases, as shown in the above table. The concession will not be paid on purchases of shares by exchange or that were previously subject to a front-end sales charge and dealer concession.

If you redeem any of those shares within a holding period of 18 months from the date of their purchase, a contingent deferred sales charge of 1.00% will be deducted from the redemption proceeds (unless you are eligible for a waiver of that sales charge based on the categories listed below and you advise the transfer agent or another intermediary of your eligibility for the waiver when you place your redemption request). The 18-month period begins on the day the purchase is made.

Prior to the thirteenth month, the Distributor will retain distribution and service fees described in the “Distribution Plan, Shareholder Servicing, and Payments to Intermediaries” section.

Class C Shares

Front-end Sales Charges

Your purchases of Class C shares are made at the NAV per share for Class C shares.

Contingent Deferred Sales Charges for Class C Shares

Although Class C shares have no front-end sales charge, they carry a contingent deferred sales charge of 1.00% that is applied to shares sold within the first year after they are purchased. After holding Class C shares for one year, you may sell them at any time without paying a contingent deferred sales charge. The Distributor pays your financial intermediary an up-front commission of 1.00% on sales of Class C shares.

Conversion of Certain Class C Shares

Prospectus. It is solely the responsibility of the respective financial intermediary to administer and support such transactions. Please consult your financial intermediary for more information.

Contingent Deferred Sales Charges for Class A and Class C Shares

As described above, certain investments in Class A and Class C shares are subject to a contingent deferred sales charge. You will pay the contingent deferred sales charge only on shares you redeem within the prescribed amount of time after purchase.The contingent deferred sales charge will be based on the lesser of the NAV of the redeemed shares at the time of redemption or the original NAV. For purposes of calculating the contingent deferred sales charge, the start of the holding period is the date on which the purchase is made. A contingent deferred sales charge is not imposed on:

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the amount of your account value represented by an increase in NAV over the initial purchase price,

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shares purchased by the reinvestment of dividends or capital gains distributions, or

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shares redeemed in the special circumstances described below.

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To determine whether a contingent deferred sales charge applies to a redemption, the Fund redeems shares in the following order:

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shares acquired by reinvestment of dividends and capital gains distributions, and

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shares held the longest.

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Contingent deferred sales charges are not charged when you exchange shares of the Fund for shares of any other Fund. However, if you exchange them within the applicable contingent deferred sales charge holding period, the holding period will carry over to the Fund whose shares you acquire. Similarly, if you acquire shares of a Fund by exchanging shares of another Fund that are still subject to a contingent deferred sales charge holding period, that holding period will carry over to the acquired Fund.

Waivers of Class A Front-end Sales Charges

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Waivers of Class A Contingent Deferred Sales Charges

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The term “immediate family” refers to one’s spouse, children, grandchildren, grandparents, parents, parents-in-law, brothers and sisters, sons- and daughters-in-law, a sibling’s spouse, a spouse’s siblings, aunts, uncles, nieces, and nephews; relatives by virtue of a remarriage (step-children, step-parents, etc.) are included.

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Shares sold to present or former officers, directors, trustees, or employees (and their “immediate families(1)”) of the Fund, MassMutual, and its affiliates.

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Reduced Class A Sales Charges for Larger Investments

previous 90 days. See the SAI for additional information about this privilege. In addition, certain investors may purchase shares at no sales charge or at a reduced sales charge. For example, Class A shares are offered at no sales charge to investors who are clients of financial intermediaries who have entered into an agreement with the Distributor to offer Fund shares through self-directed investment brokerage accounts without charging transaction fees to their clients or through other platforms. See Appendix A of this Prospectus and the SAI for a description of this and other situations in which sales charges are reduced or waived. Information regarding reduced sales charges can be found on the MassMutual website at https://www.massmutual.com/product-performance/mutual-funds.

Availability of Sales Charge Waivers and Discounts

The availability of sales charge waivers and discounts may depend on the particular financial intermediary or type of account through which you purchase or hold Fund shares. The Funds’ sales charge waivers and discounts in this Prospectus are available for qualifying purchases made directly from the Distributor and are generally available through financial intermediaries unless otherwise specified in Appendix A and the SAI or by that financial intermediary. Certain sales charge waivers and discounts available through other financial intermediaries are set forth in Appendix A to this Prospectus and the SAI, which may differ from those available for purchases made directly from the Distributor or certain other financial intermediaries, Please contact your financial intermediary for more information regarding sales charge waivers and discounts available to you and the financial intermediary’s policies and procedures.

Rule 12b-1 fees. 

Shareholder servicing payments. 

Payments to intermediaries. 

financial planners or advisers, banks, and insurance companies. In some cases, a financial intermediary may hold its clients’ Fund shares in nominee or street name. Shareholder services provided by a financial intermediary may (though they will not necessarily) include, among other things: processing and mailing trade confirmations, periodic statements, prospectuses, annual shareholder reports, semi-annual shareholder reports, shareholder notices, and other SEC-required communications; capturing and processing tax data; issuing and mailing dividend checks to shareholders who have selected cash distributions; preparing record date shareholder lists for proxy solicitations; collecting and posting distributions to shareholder accounts; and establishing and maintaining systematic withdrawals and automated investment plans and shareholder account registrations.

Additional information. 

In addition to the various payments described above, MML Advisers in its discretion may directly, or through an affiliate, pay up to 0.35% of the amount invested to intermediaries who provide services on behalf of shareholders of the Funds. This compensation is paid by MML Advisers from its own assets. The payments will be based on criteria established by MML Advisers and will be paid quarterly, in arrears.

The Distributor, MML Advisers, or MassMutual may also directly, or through an affiliate, make payments, out of its own assets, to intermediaries, including broker-dealers, insurance agents, and other service providers, that relate to the sale of shares of the Funds or certain of MassMutual’s variable annuity contracts for which the Funds are underlying investment options. This compensation may take the form of:

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Payments to administrative service providers that provide enrollment, recordkeeping, and other services to pension plans;

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Cash and non-cash benefits, such as bonuses and allowances or prizes and awards, for certain broker-dealers, administrative service providers, and MassMutual insurance agents;

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Payments to intermediaries for, among other things, training of sales personnel, conference support, marketing, or other services provided to promote awareness of MassMutual’s products;

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Payments to broker-dealers and other intermediaries that enter into agreements providing the Distributor with access to representatives of those firms or with other marketing or administrative services; and

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Payments under agreements with MassMutual not directly related to the sale of specific variable annuity contracts or the Funds, such as educational seminars and training or pricing services.

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In some instances, compensation may be made available only to certain financial intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Funds’ shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as the Financial Industry Regulatory Authority.

These compensation arrangements are not offered to all intermediaries and the terms of the arrangements may differ among intermediaries.

These arrangements may provide an intermediary with an incentive to recommend one mutual fund over another, one share class over another, or one insurance or annuity contract over another. You may want to take these compensation arrangements into account when evaluating any recommendations regarding the Funds or any contract using the Funds as investment options. You may contact your intermediary to find out more information about the compensation they may receive in connection with your investment.

your shares within seven days after your redemption request is received in good order. If, however, you request redemption of shares recently purchased by check, you may not receive payment until the check has been collected, which may take up to 15 days from time of purchase. Under unusual circumstances, the Funds can also suspend or postpone payment, when permitted by applicable law and regulations. The Funds’ transfer agent may temporarily delay for more than seven days the disbursement of redemption proceeds from the Fund account of a “Specified Adult” ​(as defined in Financial Industry Regulatory Authority Rule 2165) based on a reasonable belief that financial exploitation of the Specified Adult has occurred, is occurring, has been attempted, or will be attempted, subject to certain conditions. Under normal circumstances, each Fund expects to meet redemption requests by using cash or cash equivalents in its portfolio and/or selling portfolio assets to generate cash. Under stressed market conditions, a Fund may pay redemption proceeds using cash obtained through borrowing arrangements that may be available from time to time. To the extent consistent with applicable laws and regulations, the Funds reserve the right to satisfy all or a portion of a redemption request by distributing securities or other property in lieu of cash (“in-kind” redemptions), under both normal and stressed market conditions. Some Funds may be limited in their ability to use assets other than cash to meet redemption requests due to restrictions on ownership of their portfolio assets. The securities distributed in an in-kind redemption will be valued in the same manner as they are valued for purposes of computing the Fund’s NAV. These securities are subject to market risk until they are sold and may increase or decrease in value prior to converting them into cash. You may incur brokerage and other transaction costs, and could incur a taxable gain or loss for income tax purposes when converting the securities to cash.

verify your customer information, the Fund reserves the right to close your account or to take such other steps as it deems reasonable.

Risk of Substantial Redemptions. 

Exchanges

This restriction also does not apply to exchanges made pursuant to certain asset allocation programs, systematic exchange programs, and dividend exchange programs. If you place an order to exchange shares of one MassMutual Fund for another through a broker-dealer or other intermediary then, in order for your exchange to be effected based on the MassMutual Fund’s next determined NAVs, the broker-dealer or other intermediary must receive your request before the close of regular trading on the NYSE, and the broker-dealer or other intermediary must subsequently communicate the request properly to the MassMutual Funds.

Your right to exchange shares is subject to applicable regulatory requirements or contractual obligations. The Funds may limit, restrict, or refuse exchange purchases, if, in the opinion of MML Advisers:

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you have engaged in excessive trading;

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a Fund receives or expects simultaneous orders affecting significant portions of the Fund’s assets;

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a pattern of exchanges occurs which coincides with a market timing strategy; or

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and policies or if the Fund would be adversely affected.

The Funds reserve the right to modify or terminate the exchange privilege as described above on 60 days written notice.

The Funds do not accept purchase, redemption, or exchange orders or compute their NAVs on days when the NYSE is closed. This includes: weekends, Good Friday, and all federal holidays other than Columbus Day and Veterans Day. Certain foreign markets may be open on days when the Funds do not accept orders or price their shares. As a result, the NAV of a Fund’s shares may change on days when you will not be able to buy or sell shares.

Transaction Orders by Telephone and in Writing

In general, you may purchase, exchange, or sell (redeem) shares on any business day through your financial intermediary or by contacting the transfer agent in writing or by telephone (“MassMutual Advantage Funds – (Fund Name),” Attn: Transfer Agent, P.O. Box 219606, Kansas City, MO 64121-9606 or by telephone: 1-855-439-5459).

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The NAV of each Fund’s shares is determined once daily as of the close of regular trading on the NYSE, on each Business Day. A “Business Day” is every day the NYSE is open. The NYSE normally closes at 4:00 p.m. Eastern Time, but may close earlier on some days. If the NYSE is scheduled to close early, the Business Day will be considered to end as of the time of the NYSE’s scheduled close. A Fund will not treat an intraday disruption in NYSE trading or other event that causes an unscheduled closing of the NYSE as a close of business of the NYSE for these purposes; instead, MML Advisers will determine the fair value of a Fund’s securities in accordance with MML Advisers’ fair valuation policy and procedures. The NYSE currently is not open for trading on New Year’s Day, Martin Luther King, Jr. Day, President’s Day, Good Friday, Memorial Day, Juneteenth National Independence Day, Independence Day, Labor Day, Thanksgiving Day, and Christmas Day. Each Fund calculates the NAV of each of its classes of shares by dividing the total value of the assets attributable to that class, less the liabilities attributable to that class, by the number of shares of that class that are outstanding. On holidays and other days when the NYSE is closed, each Fund’s NAV generally is not calculated and the Funds do not anticipate accepting buy or sell orders. However, the value of each Fund’s assets may still be affected on such days to the extent that a Fund holds foreign securities that trade on days that foreign securities markets are open.

valuations taking into account factors such as institutional-size trading in similar securities, yield, quality, coupon rate, maturity, type of issue, trading characteristics, and other market data. Shares of other open-end mutual funds are valued at their closing NAVs as reported on each Business Day.