(a) In general. A plan sponsor may amend a plan without PBGC approval to adopt any of the simplified methods in this section to fulfill the requirements of section 305(g)(4) of ERISA and 432(g)(4) of the Code and § 4211.4(b)(2)(iii) for a withdrawal that occurs on or after the plan's reversion date.

(b) Reversion date. The reversion date is either—

(1) The expiration date of the first collective bargaining agreement requiring plan contributions that expires after the plan is no longer in endangered or critical status, or

(2) The date that is the later of—

(i) The end of the first plan year following the plan year in which the plan is no longer in endangered or critical status; or

(ii) The end of the plan year that includes the expiration date of the first collective bargaining agreement requiring plan contributions that expires after the plan is no longer in endangered or critical status.

(3) For purposes of paragraph (b)(2) of this section, the expiration date of a collective bargaining agreement that by its terms remains in force until terminated by the parties thereto is considered to be the earlier of—

(i) The termination date agreed to by the parties thereto; or

(ii) The first day of the third plan year following the plan year in which the plan is no longer in endangered or critical status.

(c) Example. The simplified method in paragraph (b)(1) of this section is illustrated by the following example.

(1) Facts. A plan certifies that it is not in endangered or critical status for the plan year beginning January 1, 2021. The plan operates under several collective bargaining agreements. The plan sponsor adopts a rule providing that all contribution increases will be included in the numerator and denominator of the allocation fractions for withdrawals occurring after October 31, 2022, the expiration date of the first collective bargaining agreement requiring plan contributions that expires after January 1, 2021.

(2) Allocation fraction. A contributing employer withdraws from the plan in November 2022, after the date designated by the plan sponsor for the inclusion of all contribution rate increases in the allocation fraction. The allocation fraction used by the plan sponsor to determine the employer's share of the plan's unfunded vested benefits includes all of the employer's required contributions in the numerator and total contributions made by all employers in the denominator, including any amounts related to contribution increases previously disregarded.

(d) Effective and applicability dates—(1) Effective date. This section is effective on February 8, 2021.

(2) Applicability date. This section applies to employer withdrawals from multiemployer plans that occur in plan years beginning on or after February 8, 2021.