26 U.S.C. § 6665
(a) Additions treated as tax Except as otherwise provided in this title—
(b) Procedure for assessing certain additions to tax For purposes of subchapter B of chapter 63 (relating to deficiency procedures for income, estate, gift, and certain excise taxes), subsection (a) shall not apply to any addition to tax under section 6651, 6654, or 6655; except that it shall apply—
(Added Pub. L. 101–239, title VII, § 7721(a), , 103 Stat. 2399.)
Effective Date Section applicable to returns the due date for which (determined without regard to extensions) is after , see section 7721(d) of Pub. L. 101–239, set out as an Effective Date of 1989 Amendment note under section 461 of this title.