; . (b) Conforming amendments (1) Successor employers Paragraph (1) of section 3121(a) of the Internal Revenue Code of 1986 is amended by adding at the end the following new subsection: (aa) Special rules for successor employers For purposes of subsection (a)(1), if an employer (hereinafter referred to as successor employer) during any calendar year acquires substantially all the property used in a trade or business of another employer (hereinafter referred to as a predecessor), or used in a separate unit of a trade or business of a predecessor, and immediately after the acquisition employs in his trade or business an individual who immediately prior to the acquisition was employed in the trade or business of such predecessor, then, for the purpose of determining the amount of remuneration paid by the successor employer under such subsection, any remuneration (other than remuneration referred to in the paragraphs succeeding paragraph (1) of subsection (a)) with respect to employment paid (or considered under this subsection as having been paid) to such individual by such predecessor during such calendar year and prior to such acquisition shall be considered as having been paid by such successor employer. . (2) Application to railroad retirement taxes Clause (i) of section 3231(e)(2)(A) of such Code is amended to read as follows: (i) In general For any calendar year in which the applicable base is less than $250,000, the term compensation does not include so much of the remuneration paid during any calendar year to an individual by an employer for services rendered as an employee to such employer as exceeds the applicable base but does not exceed $250,000. . (c) Effective date The amendments made by this section shall apply to remuneration paid on or after January 1 of the first calendar year that begins after the date of enactment of this Act. 7. Tax on net earnings from self-employment up to contribution and benefit base and more than $250,000 (a) In general Paragraph (1) of section 1402(b) of the Internal