Updating Summary Prospectus (Form 497VPU)

MASSMUTUAL ASCEND LIFE INSURANCE COMPANY

INDEX SUMMIT 6 ANNUITY

With Death Benefit Return of Premium Guarantee

UPDATING SUMMARY PROSPECTUS

May 1, 2026

This updating summary prospectus provides updated information about the Index Summit 6 Annuity with Death Benefit Return of Premium, an individual index-linked modified single premium deferred annuity.

The prospectus contains more information about the Index Summit 6 Annuity with Death Benefit Return of Premium Guarantee, including its features, benefits, and risks. You can find the current prospectus and other information about the Contract online at www.massmutualascend.com/RILAcompliancedocuments/Index-Summit-6. You can also obtain this information at no cost by calling 1-800-789-6771 or by sending an email request to [email protected].

Additional information about certain investment products, including registered index-linked annuities, has been prepared by the Securities and Exchange Commission's staff and is available at Investor.gov.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED THESE SECURITIES OR PASSED UPON THE ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

TABLE OF CONTENTS

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SPECIAL TERMS

In this prospectus, the following capitalized terms have the meanings set out below.

ACCOUNT VALUE. For each day, the Account Value is the sum of the current values of each Indexed Strategy, plus the current value of the Purchase Payment Account, if any.

ADJUSTED CAP. For a Combination Strategy with a Cap for the Term, the Adjusted Cap is the largest increase in the Index for the Term that is taken into account when determining the gain for the Term. It is equal to the Cap for the Term divided by the Upside Participation Rate for the Term.

ANNUITY PAYOUT BENEFIT. A series of periodic payments made under a Payout Option. The terms and conditions are described in the Annuity Payout Benefit section of the prospectus.

BUFFER. For an Indexed Strategy with a Buffer (a "Buffer Strategy"), the Buffer is the decrease in the value of an Index for a Term that is disregarded when determining the loss for the Term. The Buffer is also used to determine the strike price of the out-of-the-money put option that is part of the Daily Value Percentage calculation before the end of the Term. For each Term of the Buffer Strategy that we currently offer with this Contract, the Buffer is either 10% or 20%. In the future, we may offer a new Buffer Strategy with more or less protection against loss than a 10% or 20% Buffer, but we will not offer a new Buffer Strategy with less protection against loss than a 5% Buffer.

CAP. For an Indexed Strategy with a Cap (either a "Cap Strategy" or, if it also has an Upside Participation Rate, a Combination Strategy), the Cap is the maximum increase in the Strategy value over the course of a Term. The Cap (or for a Combination Strategy, the Adjusted Cap) is also used to determine the strike price of the out-of-the-money call option that is part of the Daily Value Percentage calculation for that Strategy before the end of the Term. We post on our website (www.massmutualascend.com/index-summit-6) the Cap for each Term of a Cap Strategy or Combination Strategy at least 10 days before the next Term starts. The Cap for a Term will never be less than 1%.

COMBINATION STRATEGY. An Indexed Strategy that has an Upside Participation Rate and may also have a Cap.

CONTRACT. The annuity contract (including applicable endorsements and riders) that is a legally binding agreement between you and MassMutual Ascend Life. In the prospectus, "Contracts" refers to all Index Summit 6 Annuity contracts.

CONTRACT ANNIVERSARY. The date in each year that is the anniversary of the Contract Effective Date. That date is set out in the Contract Specifications of your Contract.

CONTRACT EFFECTIVE DATE. The date as of which the initial Purchase Payment is applied to the Contract. That date is set out in the Contract Specifications of your Contract.

CONTRACT SPECIFICATIONS. The section of your Contract that contains details unique to your Contract.

CONTRACT YEAR. A 12-month period that starts on the Contract Effective Date or on a Contract Anniversary.

DAILY VALUE PERCENTAGE. The Daily Value Percentage is used to determine the value of an Indexed Strategy before the end of a Term. The calculation of Strategy value using the Daily Value Percentage is relevant only if amounts allocated to an Indexed Strategy are not held to the end of the Term because you take a withdrawal, Surrender or annuitize the Contract, elect a Performance Lock, or a Death Benefit becomes payable. A negative Daily Value Percentage adjustment could result in significant loss, even if the Index is performing positively.

DEATH BENEFIT. An amount that becomes payable if you die before the Annuity Payout Initiation Date and before the date that the Contract is Surrendered. The terms and conditions are described in the Death Benefit section of the prospectus.

DOWNSIDE PARTICIPATION RATE. For an Indexed Strategy with a Downside Participation Rate (a "Downside Participation Rate Strategy"), the Downside Participation Rate is your share of any fall in the Index for a Term taken into account to determine the Strategy value at the end of the Term. The Downside Participation Rate is also used to determine the Net Option Price that is part of the Daily Value Percentage calculation before the end of the Term. For every Term of each Downside Participation Rate Strategy that we currently offer with this Contract, the Downside Participation Rate is 50%. In the future, we may offer a new Downside Participation Rate Strategy with more or less protection against loss than a 50% Downside Participation Rate, but we will not offer a new Downside Participation Rate Strategy with less protection against loss than a 75% Downside Participation Rate.

EARLY WITHDRAWAL CHARGE. A charge deducted from the Account Value of your Contract if, during the first six Contract Years, you Surrender your Contract or you take a withdrawal (including systematic withdrawals and required minimum distributions) in excess of the Free Withdrawal Allowance. The Early Withdrawal Charge does not apply to a withdrawal that qualifies for the Free Withdrawal Allowance or the amount, if any, that qualifies for another waiver. The Early Withdrawal Charge does not apply to an Annuity Payout Benefit or Death Benefit.

FLOOR. For an Indexed Strategy with a Floor (a "Floor Strategy"), the Floor is the maximum decrease in the value of an Index for a Term that is taken into account when determining the loss for the Term. The Floor is also used to determine the strike price of the out-of-the-money put option that is part of the Daily Value Percentage calculation before the end of the Term. For each Term of a Floor Strategy that we currently offer with this Contract, the Floor is either -10% or 0%. In the future, we may offer a new Floor Strategy that offers more or less protection against loss than a -10% Floor but we will not offer a new Floor Strategy that offers less protection against loss than a -20% Floor.

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FREE WITHDRAWAL ALLOWANCE. The total amount that may be taken as a withdrawal or Surrendered during a Contract Year without an Early Withdrawal Charge that might otherwise apply. This amount is described in the Free Withdrawal Allowance section of the prospectus.

INDEX. A stock market index or an exchange-traded fund (ETF) used to calculate the value of an Indexed Strategy. The Index at the start of a Term is its level or price at the Market Close on the first day of that Term. If the first day of that Term is not a Market Day, then the Index at the start of a Term is its level or price at the last Market Close before the first day of the Term. The Index at the end of a Term is its level or price at the final Market Close of that Term.

INDEXED STRATEGY (or STRATEGY). A strategy that provides a return based, in part, on the net change in the level or price of an Index for a Term. The Indexed Strategies that are currently available are set out in "Appendix A: Investment Options Available Under the Contract".

INVESTMENT BASE. The base amount used to calculate the value of an Indexed Strategy. The Investment Base is the amount applied to an Indexed Strategy at the start of a current Term, adjusted proportionally for any withdrawal during the Term and any related Early Withdrawal Charge.

MARKET CLOSE. The close of the regular or core trading session on the market used to measure a given Index.

MASSMUTUAL ASCEND LIFE ("WE," "US," "OUR"). MassMutual Ascend Life Insurance Company.

OWNER ("YOU," "YOURS"). The person(s) who possesses the ownership rights under the Contract. If there is more than one Owner, each Owner will be a joint owner of the Contract and each reference to Owner means joint owners.

PAYOUT OPTION. The form in which an Annuity Payout Benefit or a Death Benefit may be paid. Standard options are described in the Payout Options section of the prospectus.

PERFORMANCE LOCK. An election available for certain specified Indexed Strategies to lock in the Daily Value Percentage for the remainder of a Term of the Indexed Strategy. A Performance Lock election for a Term is effective on the Market Close immediately following our receipt of your Request in Good Order unless you specifically request that it become effective on the second Market Close. After the Market Close upon which the Performance Lock becomes effective, the Indexed Strategy value before the end of the Term and the Indexed Strategy value at the end of the Term is equal to the remaining Investment Base increased or decreased by the locked Daily Value Percentage. The locked Daily Value Percentage is the Daily Value Percentage as determined for that Market Close. The Indexed Strategy value will still change if there is a change in the Investment Base. You can make a Performance Lock election once per Term and only for specific Indexed Strategies. A Performance Lock election is not available for Contracts issued in Missouri with a Contract Effective Date before May 21, 2025.

PURCHASE PAYMENT. An amount received by us for the Contract. This amount is determined after deducting any taxes withheld from the payment and after deducting any fee charged by the person remitting payment.

REQUEST IN GOOD ORDER. An election or a request that is:

An election or a request is complete and satisfactory when we have received: (1) all the information and legal documentation that we require to process the election or the request; and (2) instructions that are sufficiently clear that we do not need to exercise any discretion to process the election or the request. If you have any questions, you should contact us or your registered representative before submitting your election or your request.

STRATEGY APPLICATION DATE. The 6th and 20th days of each month.

SURRENDER. The termination of your Contract in exchange for its Surrender Value.

TERM. The period for which Contract values are allocated to a given Indexed Strategy, and over which values are calculated. Terms are one year long, two years long, three years long, or six years long. Each Term will start and end on a Strategy Application Date. A new Term will start on the date that the preceding Term ends.

TRIGGER RATE. For an Indexed Strategy with a Trigger Rate (a "Trigger Strategy"), the Trigger Rate is the specified rate that is credited to the Strategy value when the Index change (measured at the start and end of the Term) qualifies for the Trigger Rate. In the case of a Performance Trigger Strategy, the Trigger Rate will be credited when the Index change is zero or positive at the end of the Term. In the case of a Dual Performance Trigger Strategy, the Trigger Rate will be credited if the Index change is zero, positive, or negative up to the Buffer at the end of the Term. The Trigger Rate is also used to determine the binary call option that is part of the Daily Value Percentage calculation for that Strategy before the end of the Term. We post on our website (www.massmutualascend.com/index-summit-6) the Trigger Rates for each Term of a Trigger Strategy at least 10 days before the next Term starts. The Trigger Rate for a Term will never be less than 1%.

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UPSIDE PARTICIPATION RATE. For an Indexed Strategy with an Upside Participation Rate (an "Upside Participation Rate Strategy" or, if it may also have a Cap, a Combination Strategy), the Upside Participation Rate is your share of any rise in the Index for a Term taken into account to determine the Strategy value at the end of the Term. The Upside Participation Rate is also used to determine the Net Option Price that is part of the Daily Value Percentage calculation before the end of the Term. We post on our website (www.massmutualascend.com/index-summit-6) the Upside Participation Rate for each Term of an Upside Participation Rate Strategy or Combination Strategy at least 10 days before the next Term starts. The Upside Participation Rate for a Term will never be less than 5%. The Upside Participation Rate for a Term of a Combination Strategy will never be less than 100% when that Term has a Cap. For example, if the Index return is 10% and the Upside Participation Rate is 5%, then your Indexed Strategy value will only increase by 0.5% (10% times 5%).

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UPDATED INFORMATION ABOUT YOUR CONTRACT

The information in this Updating Summary Prospectus is a summary of certain Contract features that have changed since the Prospectus dated December 10, 2025. This may not reflect all of the changes that have occurred since you entered into your Contract. Please see the prospectus available on www.massmutualascend.com/RILAcompliancedocuments/Index-Summit-6 for more information.

PERFORMANCE LOCK

Beginning on May 1, 2026, a Performance Lock election for a Term is effective on the Market Close immediately following our receipt of your Request in Good Order unless you specifically request that it become effective on the second Market Close following our receipt of your Request in Good Order.

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IMPORTANT INFORMATION YOU SHOULD CONSIDER ABOUT THE CONTRACT

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APPENDIX A: INVESTMENT OPTIONS AVAILABLE UNDER THE CONTRACT

The following is a list of Indexed Strategies currently available under the Contract. We may change the features of the Indexed Strategies listed below (including the Index and the current limits on Index gains and losses), offer new Indexed Strategies, and terminate existing Indexed Strategies. We will provide you with written notice before making any changes other than changes to current limits on Index gains. Information about current limits on Index gains is available at www.massmutualascend.com/index-summit-6. For additional information about the features of the Indexed Strategies, please see the "Indexed Strategies" section in the prospectus. The practical availability of investment options at the time of sale may vary depending on the broker-dealer through which the Contract is sold. See Appendix D - Financial Intermediary Variations in the prospectus.

Note: If amounts are removed from an Indexed Strategy before the end of its Term, we will apply a Daily Value Percentage adjustment. This may result in a significant reduction in your Strategy value that could exceed any protection from Index loss that would be in place if you held the Indexed Strategy until the end of the Term. You may not be able to invest in certain Indexed Strategies, as noted below.

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The following eight additional Indexed Strategies are available for Contracts with a Contract Effective Date before February 21, 2026. These Indexed Strategies will continue to be available for Contracts issued in California before a date to be specified by a supplement to this prospectus after regulatory approval of the Combination Strategies is received.

The S&P 500 is a "price return index," not a "total return index," and therefore does not reflect dividends paid on the securities composing the Index. This will reduce the Index return and cause the Index to underperform a direct investment in the securities composing the Index.

The iShares MSCI EAFE ETF deducts fees and costs when calculating Index performance. This will reduce the ETF's return and cause the ETF to underperform a direct investment in the securities composing the ETF.

The iShares US Real Estate ETF deducts fees and costs when calculating Index performance. This will reduce the ETF's return and cause the ETF to underperform a direct investment in the securities composing the ETF.

The SPDR Gold Shares ETF deducts fees and costs when calculating Index performance. This will reduce the ETF's return and cause the ETF to underperform a direct investment in gold bullion.

The First Trust Barclays Edge is an "excess return index" that subtracts a risk-free interest rate from the price and dividend return of the securities. It also deducts fees and costs when calculating Index performance. This will reduce the Index's return and cause the Index to underperform a direct investment in the securities composing the Index.

The Russell 2000 is a "price return index," not a "total return index," and therefore does not reflect dividends paid on the securities composing the Index. This will reduce the Index return and cause the Index to underperform a direct investment in the securities composing the Index.

Possible Changes in Indexed Strategies.

The S&P 500 1-Year 50% Downside Participation Rate with Upside Participation Rate Indexed Strategy will always be available. At the end of a Term, we may stop offering any other Indexed Strategy. Consequently, any other Indexed Strategy listed above may not be available after the end of the initial Term. We have the right to replace the Index associated with an Indexed Strategy under certain circumstances.

In the future, we may offer new Indexed Strategies. Any new Buffer Strategy will offer protection against loss at least equal to a 5% Buffer. Any new Floor Strategy will offer protection against loss at least equal to a -20% Floor. Any new Downside Participation Rate Strategy will offer protection against loss at least equal to a 75% Downside Participation Rate.

Positive return factors can change from one Term to the next, subject to the following minimum rates: A Cap will never be lower than 1%, an Upside Participation Rate will never be lower than 5%, and a Trigger Rate will never be lower than 1%. Indexed Strategies that may be available in the future may earn a return that is lower than the return your investments would have earned if they had been invested in the other Indexed Strategies that are currently available. In addition, any reduction in the available number of Indexed Strategies may reduce your opportunity to increase your Contract value.

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This summary prospectus incorporates by reference the statutory prospectus and statement of additional information ("SAI") for the contract, both dated May 1, 2026, as may be amended or supplemented from time to time. The SAI may be obtained, free of charge, in the same manner as the statutory prospectus.

EDGAR contract identifier: C000261641

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