§ 1401.
(a)
Old-age, survivors, and disability insurance
In addition to other taxes, there shall be imposed for each taxable year, on the self-employment income of every individual, a tax equal to 12.4 percent of the amount of the self-employment income for such taxable year.
([Aug. 16, 1954, ch. 736], [68A Stat. 353]; [Sept. 1, 1954, ch. 1206], title II, § 208(a), [68 Stat. 1093]; [Aug. 1, 1956, ch. 836], title II, § 202(a), [70 Stat. 845]; [Pub. L. 85–840, title IV, § 401(a)], Aug. 28, 1958, [72 Stat. 1041]; [Pub. L. 87–64, title II, § 201(a)], June 30, 1961, [75 Stat. 140]; [Pub. L. 89–97, title I, § 111(c)(4)], title III, § 321(a), July 30, 1965, [79 Stat. 342], 394; [Pub. L. 90–248, title I, § 109(a)(1)], (b)(1), Jan. 2, 1968, [81 Stat. 835], 836; [Pub. L. 92–336, title II, § 204] (a)(1), (b)(1), July 1, 1972, [86 Stat. 420], 421; [Pub. L. 92–603, title I, § 135(a)(1)], (b)(1), Oct. 30, 1972,