A prior section 668, acts Aug. 16, 1954, ch. 736, 68A Stat. 225; Oct. 16, 1962, Pub. L. 87–834, § 7(d), 76 Stat. 986; Dec. 30, 1969, Pub. L. 91–172, title III, § 331(a), 83 Stat. 594, related to treatment of amounts deemed distributed in preceding years, prior to repeal by Pub. L. 94–455, title VII, § 701(a)(3), Oct. 4, 1976, 90 Stat. 1577. See section 667 of this title.

1996—Subsec. (a). Pub. L. 104–188 reenacted heading without change and amended text generally. Prior to amendment, text read as follows: “For purposes of the tax determined under section 667 (a), the interest charge is an amount equal to 6 percent of the partial tax computed under section 667 (b) multiplied by a fraction—

“(1) the numerator of which is the sum of the number of taxable years between each taxable year to which the distribution is allocated under section 666 (a) and the taxable year of the distribution (counting in each case the taxable year to which the distribution is allocated but not counting the taxable year of the distribution), and

“(2) the denominator of which is the number of taxable years to which the distribution is allocated under section 666 (a).”

1990—Subsec. (c). Pub. L. 101–508 substituted heading for one which read “Special rules” and amended text generally, restating provisions of former par. (1) as entire subsection and striking out former par. (2) which provided that for purposes of this section, undistributed net income existing in a trust as of January 1, 1977, would be treated as allocated under section 666 (a) to the first taxable year beginning after December 31, 1976.

Section 1906(d)(1) of Pub. L. 104–188 provided that: “The amendment made by subsection (a) [amending this section] shall apply to distributions after the date of the enactment of this Act [Nov. 20, 1996].”

Section 1014(d) of Pub. L. 94–455 provided that: “The amendments made by this section [enacting this section and amending section 667 of this title] shall apply to taxable years beginning after December 31, 1976.”

For provisions that nothing in amendment by Pub. L. 101–508 be construed to affect treatment of certain transactions occurring, property acquired, or items of income, loss, deduction, or credit taken into account prior to Nov. 5, 1990, for purposes of determining liability for tax for periods ending after Nov. 5, 1990, see section 11821(b) of Pub. L. 101–508, set out as a note under section 45K of this title.