Section, added June 29, 1956, ch. 463, § 1, 70 Stat. 402; amended Mar. 31, 1976, Pub. L. 94–253, § 1(a), (d), 90 Stat. 295, 296; Oct. 4, 1976, Pub. L. 94–455, title XIX, § 1901(a)(53), (b)(10)(A), (14)(B), (C), 90 Stat. 1773, 1795, 1796; Nov. 6, 1978, Pub. L. 95–600, title III, § 369(a), 92 Stat. 2857; Apr. 1, 1980, Pub. L. 96–222, title I, § 103(a)(14), 94 Stat. 214; Oct. 22, 1986, Pub. L. 99–514, title XVIII, § 1899A(9), 100 Stat. 2958, related to nonrecognition of gain or loss in certain railroad reorganizations.

For provisions that nothing in repeal by Pub. L. 101–508 be construed to affect treatment of certain transactions occurring, property acquired, or items of income, loss, deduction, or credit taken into account prior to Nov. 5, 1990, for purposes of determining liability for tax for periods ending after Nov. 5, 1990, see section 11821(b) of Pub. L. 101–508, set out as a note under section 45K of this title.