; and (B) the denominator of which is the total revenue from taxation of social security benefits. (3) Transfers The amounts appropriated by paragraph (2) to any payor fund shall be transferred from time to time (but not less frequently than quarterly) from the general fund of the Treasury on the basis of estimates made by the Secretary of the Treasury of the amounts referred to in such paragraph. Any such quarterly payment shall be made on the first day of such quarter and shall take into account social security benefits estimated to be received during such quarter. Proper adjustments shall be made in the amounts subsequently transferred to the extent prior estimates were in excess of or less than the amounts required to be transferred. (4) Definitions For purposes of this subsection— (A) Total revenue from taxation of social security benefits The term total revenue from taxation of social security benefits means the amount equivalent to the net revenues received in the Treasury attributable to the application of sections 86 and 871(a)(3) of the Internal Revenue Code of 1986 to payments from any payor fund made in taxable years beginning after December 31, 2024, and before January 1, 2035. (B) Payor fund The term payor fund means any trust fund or account from which payments of social security benefits are made. (C) Social security benefits The term social security benefits has the meaning given such term by section 86(d)(1) of the Internal Revenue Code of 1986. (5) Conforming amendment Section 121(e) of the Social Security Amendments of 1983 ( 42 U.S.C. 401 note) is repealed. (d) Effective date The amendments made by this section shall apply to taxable years beginning after December 31, 2024, and before January 1, 2035. 105. Improving benefits for widows and widowers in two-income households (a) In general (1) Widows Section 202(e) of the Social Security Act ( 42 U.S.C. 402(e) ) is amended— (A) in paragraph (1)— (i) in subparagraph (B), by inserting and at the end