§ 6662.
(b)
Portion of underpayment to which section applies
This section shall apply to the portion of any underpayment which is attributable to 1 or more of the following:
(1)
Negligence or disregard of rules or regulations.
(2)
Any substantial understatement of income tax.
(3)
Any substantial valuation misstatement under chapter 1.
(4)
Any substantial overstatement of pension liabilities.
(5)
Any substantial estate or gift tax valuation understatement.
(6)
Any disallowance of claimed tax benefits by reason of a transaction lacking economic substance (within the meaning of section 7701(o)) or failing to meet the requirements of any similar rule of law.
(7)
Any undisclosed foreign financial asset understatement.
(8)
Any inconsistent estate basis.
(9)
Any overstatement of the deduction provided in section 170(p).
(10)
Any disallowance of a deduction by reason of section 170(h)(7).
This section shall not apply to any portion of an underpayment on which a penalty is imposed under section 6663. Except as provided in paragraph (1) or (2)(B) of section 6662A(e), this section shall not apply to the portion of any underpayment which is attributable to a reportable transaction understatement on which a penalty is imposed under section 6662A.
(Added [Pub. L. 101–239, title VII, § 7721(a)], Dec. 19, 1989, [103 Stat. 2395]; amended [Pub. L. 101–508, title XI, § 11312(a)], (b), Nov. 5, 1990, [104 Stat. 1388–454], 1388–455; [Pub. L. 103–66, title XIII], §§ 13236(a)–(d), 13251(a), Aug. 10, 1993, [107 Stat. 505], 506, 531; [Pub. L. 103–465, title VII, § 744(a)], (b), Dec. 8, 1994, [108 Stat. 5011]; [Pub. L. 105–34, title X, § 1028(c)], Aug. 5, 1997, [111 Stat. 928]; [Pub. L. 108–357, title VIII], §§ 812(b), (d), (e)(1), 819(a), (b), Oct. 22, 2004, [118 Stat. 1578], 1580, 1584; [Pub. L. 109–135, title IV], §§ 403(x)(1), 412(aaa), Dec. 21, 2005, [119 Stat. 2629], 2641; [Pub. L. 109–280, title XII, § 1219(a)(1)], (2), Aug. 17, 2006, [120 Stat. 1083]; [Pub. L. 111–147, title V, § 512(a)], Mar. 18, 2010, [124 Stat. 110]; [Pub. L. 111–152, title I, § 1409(b)(1)], (2), Mar. 30, 2010, [124 Stat. 1068], 1069; [Pub. L. 113–295, div. A, title II, § 208(a)], Dec. 19, 2014, [128 Stat. 4028]; [Pub. L. 114–41, title II, § 2004(c)], July 31, 2015, [129 Stat. 456]; [Pub. L. 115–97, title I, § 11011(c)], Dec. 22, 2017, [131 Stat. 2070]; [Pub. L. 115–141, div. T, § 101(a)(2)(A)], div. U, title I, § 104(a), title IV, § 401(a)(303), (304), Mar. 23, 2018, [132 Stat. 1155], 1170, 1199;