M & K Employee Solutions, Inc. v. Trustees of IAM Nat. Pension

608 U. S. 264 (2026) · 5/21/26

The provisions of ERISA governing the calculation of withdrawal liability from an underfunded Multiemployer Pension Plan— i.e., the withdrawing employer’s share of the plan’s unfunded vested benefits—do not require that actuarial assumptions underlying the calculation be selected on or before the statutory measurement date. 29 U. S. C. §§1391, 1393.

Pursuant to the Employee Retirement Income Security Act of 1974 (ERISA), as amended, an employer that stops participating in an underfunded Multiemployer Pension Plan (MPP), must pay the plan “withdrawal liability,” i.e., the employer's share of the plan's unfunded vested benefits (UVBs). See 29 U. S. C. § 1391. Withdrawal liability is calculated based on the plan's UVBs “as of” the statutory measurement date—the last day of the plan year preceding the employer's withdrawal. §§ 1391(b)(2)(E)(i), (c)(2)(C)(i), (3)(A), (4)(A). Determining the value of a plan's UVBs depends upon both hard data…

Held: The provisions of ERISA governing the calculation of withdrawal liability—§§ 1391 and 1393—do not require the actuarial assumptions underlying that calculation to be selected on or before the measurement date. Pp. 271–277. (a) Section 1391 requires withdrawal liability to be calculated based on the value of a plan's UVBs “as of” the measurement date. Petitioners contend that §1391's “as of” language establishes a deadline for the selection of actuarial assumptions. But § 1391 sets no such deadline. The term “as of” is understood “to assign an event to one time and the recognition of it…