The Railroad Retirement Act of 1937, referred to in text, is act Aug. 29, 1935, ch. 812, 49 Stat. 867, as amended generally by act June 24, 1937, ch. 382, part I, 50 Stat. 307, and which was classified principally to subchapter III (§ 228a et seq.) of chapter 9 of Title 45, Railroads. The Railroad Retirement Act of 1937 was amended generally and redesignated the Railroad Retirement Act of 1974 by Pub. L. 93–445, title I, Oct. 16, 1974, 88 Stat. 1305. The Railroad Retirement Act of 1974 is classified generally to subchapter IV (§ 231 et seq.) of chapter 9 of title 45. For complete classification of these Acts to the Code, see Tables.

Section was enacted as part of the Social Security Amendments of 1965 and also as part of the Health Insurance for the Aged Act, and not as part of the Social Security Act which comprises this chapter.

Section 111(e) of Pub. L. 89–97 provided that:

“(1) The amendments made by the preceding provisions of this section [enacting this section and section 228s–2 of Title 45, Railroads, and amending section 1395kk of this title and sections 1401, 3101, 3111, 3201, 3211, and 3221 of Title 26, Internal Revenue Code, and section 228e of Title 45] shall apply to the calendar year 1966 or to any subsequent calendar year, but only if the requirement in paragraph (2) has been met with respect to such calendar year.

“(2) The requirement referred to in paragraph (1) shall be deemed to have been met with respect to any calendar year if, as of the October 1 immediately preceding such calendar year, the Railroad Retirement Tax Act [section 3101 et seq. of Title 26] provides that the maximum amount of monthly compensation taxable under such Act during all months of such calendar year will be an amount equal to one-twelfth of the maximum wages which the Federal Insurance Contributions Act [section 3201 et seq. of Title 26] provides may be counted for such calendar year.”