Amendments
1986—[Pub. L. 99–514] substituted “the underpayment rate established under section 6621” for “an annual rate established under section 6621”.
1975—[Pub. L. 93–625] substituted “an annual rate established under section 6621” for “the rate of 6 percent per annum”.
Statutory Notes and Related Subsidiaries
Effective Date of 1986 Amendment
Amendment by [Pub. L. 99–514] applicable for purposes of determining interest for periods after Dec. 31, 1986, see [section 1511(d) of Pub. L. 99–514], set out as a note under section 47 of this title.
Effective Date of 1975 Amendment
Amendment by [Pub. L. 93–625] effective July 1, 1975, and applicable to amounts outstanding on such date or arising thereafter, see [section 7(e) of Pub. L. 93–625], set out as an Effective Date note under section 6621 of this title.