The Susan Muffley Act of 2025 aims to significantly increase the pension benefits guaranteed to participants and beneficiaries of certain terminated plans. Specifically, it directs the Pension Benefit Guaranty Corporation (PBGC) to pay the full vested plan benefit , overriding previous limitations on guaranteed amounts under ERISA Section 4022. This change applies to eligible individuals from designated plans, including the Delphi Hourly-Rate Employees Pension Plan and the Delphi Retirement Program for Salaried Employees, among others. For those who have already received payments, the bill requires the PBGC to recalculate benefits and make a lump-sum payment of any past-due amounts within 180 days of enactment. These lump-sum payments will include an additional amount to account for 6 percent annual interest on the underpaid benefits. To fund these increased benefits and associated administrative costs, the Act establishes the Delphi Full Vested Plan Benefit Trust Fund within the U.S. Treasury, to be supported by general appropriations. The bill also includes provisions for the tax treatment of these lump-sum payments, allowing for ratable inclusion in gross income over three years.