Section 2521, referred to in subsec. (d)(2), was repealed by Pub. L. 94–455, title XX, § 2001(b)(3), Oct. 4, 1976, 90 Stat. 1849.

The Internal Revenue Code of 1939, referred to in subsec. (d)(5), is act Feb. 10, 1939, ch. 2, 53 Stat. 1, as amended. Prior to the enactment of the Internal Revenue Code of 1986 [formerly I.R.C. 1954], the 1939 Code was classified to former Title 26, Internal Revenue Code. For table of comparisons of the 1939 Code to the 1986 Code, see Table I preceding section 1 of this title.

1984—Subsec. (e). Pub. L. 98–369 added subsec. (e).

1981—Subsec. (d)(2). Pub. L. 97–34 substituted “calendar year (or preceding calendar period)” for “calendar quarter (or calendar year if the gift was made before January 1, 1971)” and “calendar year or period” for “calendar quarter or year” in two places.

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

Subsec. (d)(1)(A), (B). Pub. L. 94–455, § 1901(a)(122), substituted “September 2, 1958” for “the date of enactment of the Technical Amendments Act of 1958”.

Subsec. (d)(6). Pub. L. 94–455, § 2005(c), added par. (6).

1970—Subsec. (d)(2). Pub. L. 91–614 substituted “calendar quarter (or calendar year if the gift was made before January 1, 1971)” for “calendar year” the first place it appears and “calendar quarter or year” for “calendar year” every other place it appears.

1958—Subsec. (d). Pub. L. 85–866 added subsec. (d).

Amendment by Pub. L. 98–369 applicable to transfers after July 18, 1984, in taxable years ending after such date, subject to election to have amendment apply to transfers after 1983 or to transfers pursuant to existing decrees, see section 421(d) of Pub. L. 98–369, set out as an Effective Date note under section 1041 of this title.

Amendment by Pub. L. 97–34 applicable with respect to gifts made after Dec. 31, 1981, see section 442(e) of Pub. L. 97–34, set out as a note under section 2501 of this title.

Amendment by section 1901(a)(122) 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 2005(f) of Pub. L. 94–455, as amended by Pub. L. 95–600, title V, § 515(6), Nov. 6, 1978, 92 Stat. 2884, provided that:

“(1) Except as provided in paragraph (2), the amendments made by this section [enacting sections 1023, 1040, 6039A, and 6694 of this title, amending sections 691, 1016, and 1246 of this title, and renumbering former section 1023 as 1024] shall apply in respect of decedents dying after December 31, 1979.

“(2) The amendment made by subsection (c) [amending this section] shall apply to gifts made after December 31, 1976.”

Amendment by Pub. L. 91–614 applicable with respect to gifts made after Dec. 31, 1970, see section 102(e) of Pub. L. 91–614, set out as a note under section 2501 of this title.

Amendment by Pub. L. 85–866 applicable to taxable years beginning after Dec. 31, 1953, and ending after Aug. 16, 1954, see section 1(c)(1) of Pub. L. 85–866, set out as a note under section 165 of this title.