Supreme Court of the United States / October Term 2025

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

Decided May 21, 2026. Ketanji Brown Jackson delivered the opinion of the Court.

Docket 23-1209 · 608 U.S. ___ (2026)

Holding

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.

The Court’s statement of the holding, from the opinion’s syllabus. The syllabus is prepared by the Reporter of Decisions and is not part of the opinion of the Court. Read the official opinion for authority.

How the Justices voted

Decided 9–0.

“Concurring” means agreeing with the outcome; any split shown is the Court’s judgment, not each Justice’s reasoning. The lineup is the syllabus’s disposition of who wrote and joined each opinion. Source: the opinion’s syllabus (supremecourt.gov).

Official text

Read the official opinion (PDF, supremecourt.gov)

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Ketanji Brown Jackson’s profile · All Supreme Court opinions · The Supreme Court

Source: Supreme Court of the United States, slip opinions (2026). Data last verified 2026-08-15. Informational only; verify against the primary source before relying. Not a consumer report (FCRA).