26 CFR § 1.66-5
Effective date
June 25, 2020
Sections 1.66-1 through 1.66-4 are applicable on July 10, 2003. In addition, §1.66-4 applies to any request for relief filed prior to July 10, 2003, for which the Internal Revenue Service has not issued a preliminary determination as of July 10, 2003.
[T.D. 9074, 68 FR 41070, July 10, 2003]