(1) in the case of the tax imposed by section 1401(a)— (A) in the case of a taxpayer with wages (as determined under section 3121(a) without regard to paragraph (1) of such section) less than $300,000 and more than the contribution and benefit base (as determined under section 230 of the Social Security Act) which is effective for the calendar year in which such taxable year begins, the lesser of— (i) the excess of $300,000 over the wages (as so determined) paid to such individual during such taxable year, or (ii) the net earnings from self-employment for the taxable year, and (B) in the case of a taxpayer with wages (as so determined) less than or equal to such contribution and benefit base and for whom the sum, for the taxable year, of net earnings from self-employment and wages (as so determined) paid to such individual is greater than such contribution and benefit base, the lesser of— (i) the excess of such sum over such contribution and benefit base, or (ii) the excess of $300,000 over such contribution and benefit base. . (B) Phaseout Subsection (b) of section 1402 of the Internal Revenue Code of 1986 is amended by adding at the end the following: Paragraph (1) shall apply only to taxable years beginning in calendar years for which the contribution and benefit base (as determined under section 230 of the Social Security Act) is less than $300,000. . (2) Amendments to the Social Security Act (A) In general Section 211(b)(1) of the Social Security Act ( 42 U.S.C. 411(b) ) is amended— (i) in subparagraph (I)— (I) by inserting and before 2018 after 1974