2001—Subsec. (a). Pub. L. 107–16, §§ 532(c)(1), 901, temporarily struck out “the credit for State death taxes provided by section 2011 and” before “the unified credit”. See Effective and Termination Dates of 2001 Amendment note below.

1981—Subsec. (b)(2). Pub. L. 97–34 substituted “the amount of such value, reduced as provided in paragraph (1)” for “an amount which bears the same ratio to such value (reduced as provided in paragraph (1) of this subsection) as the aggregate amount of the marital deductions allowed under section 2056 (a) bears to the aggregate amount of such marital deductions computed without regard to subsection (c) thereof”.

1976—Subsec. (a). Pub. L. 94–455, § 2001(c)(1)(B), substituted “provided by section 2011 and the unified credit provided by section 2010” for “provided by section 2011”.

Subsec. (b). Pub. L. 94–455, § 1902(a)(1)(A), added heading and substituted a comma for a dash after “deduction)” in pars. (2) and (3).

Subsec. (c). Pub. L. 94–455, § 1902(a)(1)(B), added heading.

Subsec. (d). Pub. L. 94–455, § 1902(a)(1)(C), (D), added headings for subsec. (d) and for pars. (1) and (2).

Subsec. (e). Pub. L. 94–455, § 2001(a)(3), added subsec. (e).

1970—Subsec. (b)(1). Pub. L. 91–614, § 102(d)(2)(A), substituted “the calendar quarter (or calendar year if the gift was made before January 1, 1971)” for “the year”.

Subsec. (d). Pub. L. 91–614, § 102(d)(2)(B), substituted “such quarter or year” for “such year” in two places.

Subsec. (d)(1). Pub. L. 91–614, § 102(d)(2)(A), substituted “the calendar quarter (or calendar year if the gift was made before January 1, 1971)” for “the year”.

Amendment by Pub. L. 107–16 applicable to estates of decedents dying, and generation-skipping transfers, after Dec. 31, 2004, see section 532(d) of Pub. L. 107–16, set out as a note under section 2011 of this title.

Amendment by Pub. L. 107–16 inapplicable to estates of decedents dying, gifts made, or generation skipping transfers, after Dec. 31, 2010, and the Internal Revenue Code of 1986 to be applied and administered to such estates, gifts, and transfers as if such amendment had never been enacted, see section 901 of Pub. L. 107–16, set out as a note under section 1 of this title.

Amendment by Pub. L. 97–34 applicable to estates of decedents dying after Dec. 31, 1981, but inapplicable under certain conditions under will executed before date which is 30 days after Aug. 13, 1981, or under trust created by such date, see section 403(e) of Pub. L. 97–34, set out as a note under section 2056 of this title.

Amendment by section 1902(a)(1) of Pub. L. 94–455 applicable to estates of decedents dying after Oct. 4, 1976, see section 1902(c)(1) of Pub. L. 94–455, set out as a note under section 2011 of this title.

Amendment by section 2001(a)(3), (c)(1)(B) of Pub. L. 94–455 applicable to estates of decedents dying after Dec. 31, 1976, see section 2001(d)(1) of Pub. L. 94–455, set out as a note under section 2001 of this title.

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.