26 CFR § 1.1377-3 - Applicability dates.
(a) In general. Except as otherwise provided in this section, §§ 1.1377–1 and 1.1377–2 apply to taxable years of an S corporation beginning after December 31, 1996.
(b) Certain conversions. Section 1.1377–1(a)(2)(iii) and (c)(3) (Example 3) are applicable for taxable years beginning on and after May 14, 2002.
(c) Special treatment of distributions of money during post-termination transition period—(1) In general. Except as provided in paragraph (c)(2) of this section, § 1.1377–2(b) applies to taxable years beginning after October 20, 2020. For taxable years beginning on or before October 20, 2020, see § 1.1377–2(b) as contained in 26 CFR part 1, revised April 1, 2020.
(2) Taxable years beginning on or before October 20, 2020. A corporation may choose to apply § 1.1377–2(b) to taxable years beginning on or before October 20, 2020 and with respect to which the period described in section 6501(a) has not expired. If a corporation makes the choice described in the previous sentence, all shareholders of the corporation must report consistently, and the corporation must adopt §§ 1.481–5, 1.1371–1, 1.1371–2, if an ETSC, and 1.1377–2(b) in their entity and continue to apply those rules in their entirety for the corporation's subsequent taxable years.