§ 4211.21 Changes subject to PBGC approval.
(a) General rule. Subject to the approval of the PBGC pursuant to this subpart, a plan, other than a plan that primarily covers employees in the building and construction industry, may adopt, by amendment, any allocation method or modification to an allocation method that is not permitted under subpart B of this part.
(b) Building and construction industry plans. Subject to the approval of the PBGC pursuant to this subpart, a plan that primarily covers employees in the building and construction industry may adopt, by amendment, any allocation method or modification to an allocation method that is not permitted under section 4211 of ERISA if the method or modification is applicable only to its employers that are not construction industry employers within the meaning of section 4203(b)(1)(A) of ERISA.