1986—Subsec. (c)(3). Pub. L. 99–514 added par. (3).

1976—Subsec. (d)(1). Pub. L. 94–455, § 1906(b)(13)(A), struck out “or his delegate” after “Secretary”.

Subsec. (d)(1)(A). Pub. L. 94–455, § 1901(a)(30), substituted “August 16, 1954” for “the date on which this title is enacted” after “and ends after”.

Subsecs. (d)(2), (e). Pub. L. 94–455, § 1906(b)(13)(A), struck out “or his delegate” after “Secretary”.

1968—Subsec. (c)(1). Pub. L. 90–630, § 5(a), in text following subpar. (B), designated as cl. (i) existing provisions covering amounts which, if paid or incurred by the taxpayer, would without regard to the exception constitute deductible expenditures, and added cl. (ii).

Subsec. (f). Pub. L. 90–630, § 5(b), added subsec. (f).

Section 401(b) of Pub. L. 99–514 provided that: “The amendment made by this section [amending this section] shall apply to amounts paid or incurred after December 31, 1986, in taxable years ending after such date.”

Amendment by section 1901(a)(30) of Pub. L. 94–455 applicable with respect to taxable years beginning after Dec. 31, 1976, see section 1901(d) of Pub. L. 94–455, set out as a note under section 2 of this title.

Section 5(c) of Pub. L. 90–630 provided that: “The amendments made by subsections (a) and (b) [amending this section] shall apply to assessments levied after the date of the enactment of this Act [Oct. 22, 1968] in taxable years ending after such date.”