26 C.F.R. § 301.7430-6
Sections 301.7430-2 through 301.7430-6 , other than §§ 301.7430-2(b)(2), (c)(3)(i)(B), (c)(3)(i)(E), (c)(3)(ii)(C), (c)(3)(iii)(C), (c)(5), (c)(7), and (e) ; §§ 301.7430-3(c)(1), (c)(3), (c)(4), and (d) ; §§ 301.7430-4(b)(3)(i), (b)(3)(ii), (b)(3)(iii)(B), (b)(3)(iii)(C), (b)(3)(iii)(D), (b)(3)(iii)(E), (b)(3)(iii)(F), (c)(2)(ii), (c)(4), and (d) ; and §§ 301.7430-5(a), (b), (c)(3), (d)(2), (d)(3), (d)(4), (d)(5), (d)(7), (f)(2), (g)(1), (g)(2), (g)(3), (g)(5), and (g)(6) apply to claims for reasonable administrative costs filed with the Internal Revenue Service after December 23, 1992, with respect to costs incurred in administrative proceedings commenced after November 10, 1988. Section 301.7430-2(c)(5) is applicable to costs incurred and services performed in cases in which the petition was filed on or after March 1, 2016, except for the last two sentences, which are applicable March 23, 1993. Sections 301.7430-2(b)(2), and (c)(3)(i)(B) (except the last sentence); 301.7430-4(b)(3)(ii), (b)(3)(iii)(C) (except the first two sentences), and (c)(2)(ii) (except for references to the statutory cap as $125); and 301.7430-5(a) (except the parenthetical of 5(a) and all of 5(a)(1)), and the first and last sentence of (d)(7) are applicable for administrative proceedings commenced after July 30, 1996. Sections 301.7430-1(e) , 301.7430-2(c)(2) , 7430-3(a)(4) and (b) are applicable with respect to actions taken by the Internal Revenue Service after July 22, 1998. The last sentence of § 301.7430-2(c)(3)(i)(B) , the first two sentences of § 301.7430-2(b)(3)(iii)(C) , §§ 301.7430-2(c)(3)(i)(E), (c)(3)(ii)(C), (c)(3)(iii)(C), (c)(7), (e) ; 301.7430-3(c)(1), (c)(3), (c)(4), (d) ; 301.7430-4(b)(3)(i), (b)(3)(iii)(B), (b)(3)(iii)(E), (b)(3)(iii)(F), (c)(2)(ii) (to the extent it references the statutory cap as $125), (c)(4), (d); the parenthetical of § 301.7430-5(a) and §§ 301.7430-5(a)(1), (b), (d)(2), (d)(3), (d)(4), (d)(5), (d)(7) , except the first and last sentences, (f)(2), (g)(1), (g)(2), (g)(3), (g)(5), and (g)(6) apply to costs incurred and services performed in cases in which the petition was filed on or after March 1, 2016.
26 C.F.R. §301.7430-6