1980—Subsec. (c). Pub. L. 96–222 inserted “(other than the tax imposed by section 55)” after “equal to the taxes”.

1978—Subsec. (b). Pub. L. 95–600 inserted “(other than the tax imposed by section 55)” after “equal to the taxes”.

1976—Subsec. (e). Pub. L. 94–455 added subsec. (e).

1969—Subsec. (a). Pub. L. 91–172 substituted in first sentence “In the case of a trust which is subject to subpart (C)” for “In the case of a trust (other than a foreign trust created by a United States person) which for a taxable year beginning after December 31, 1953, is subject to subpart (C)”, “for a taxable year” for “for such taxable year”, and “undistributed net income for all earlier preceding taxable years” for “undistributed net incomes for any taxable years intervening between the taxable year with respect to which the accumulation distribution is determined and such preceding taxable year” and in second sentence “for such” for “of such”, inserted in first sentence “, commencing with the earliest of such years,” after “preceding taxable years”, struck out “5” before “preceding taxable years” in first and third sentences and last sentence which read as follows: “In the case of a foreign trust created by a United States person, this subsection shall apply to the preceding taxable years of the trust without regard to any provision of the preceding sentences which would (but for this sentence) limit its application to the 5 preceding taxable years.”

Subsec. (b). Pub. L. 91–172 inserted “attributable to the undistributed net income” after “taxable year” in second sentence and “attributable to such undistributed net income” before “shall be computed” in third sentence.

Subsec. (c). Pub. L. 91–172 inserted “attributable to the undistributed net income” before “multiplied by the ratio” in second sentence and “attributable to such undistributed net income” before “shall be computed” in third sentence.

Subsec. (d). Pub. L. 91–172 added subsec. (d).

1962—Subsec. (a). Pub. L. 87–834 inserted “(other than a foreign trust created by a United States person)” after “In the case of a trust”, and inserted sentence making this subsection applicable, in the case of a foreign trust created by a United States person, to the preceding taxable years of the trust without regard to any provision of the preceding sentences of this subsection which would (but for this sentence) limit its application to the 5 preceding taxable years.

Amendment by Pub. L. 96–222 effective, except as otherwise provided, as if it had been included in the provisions of the Revenue Act of 1978, Pub. L. 95–600, to which such amendment relates, see section 201 of Pub. L. 96–222, set out as a note under section 32 of this title.

Amendment by Pub. L. 95–600 applicable to taxable years beginning after Dec. 31, 1978, see section 421(g) of Pub. L. 95–600, set out as a note under section 5 of this title.

Amendment by Pub. L. 94–455 applicable to distributions made in taxable years beginning after Dec. 31, 1975, see section 701(h) of Pub. L. 94–455, set out as a note under section 667 of this title.

Amendment by Pub. L. 91–172 applicable to taxable years beginning after Dec. 31, 1968, except that for taxable years of a trust beginning before Jan. 1, 1970, first sentence of subsec. (a) not applicable and amount of accumulation distribution stated, see section 331(d)(1), (2)(B) of Pub. L. 91–172, set out as a note under section 665 of this title.

Amendment by Pub. L. 87–834 applicable with respect to distributions made after Dec. 31, 1962, see section 7(j) of Pub. L. 87–834, set out as a note under section 643 of this title.