Title 29, LaborRelease 119-110

§1393 Actuarial Assumptions

Title 29 › CHAPTER 18 — EMPLOYEE RETIREMENT INCOME SECURITY PROGRAM › SUBCHAPTER III — PLAN TERMINATION INSURANCE › Subtitle E — Special Provisions for Multiemployer Plans › part 1 — employer withdrawals › § 1393

Last updated Sep 22, 2026|Official source

Summary

Sets rules for how a plan actuary figures the unfunded vested benefits used to compute an employer’s withdrawal liability. The corporation can make rules about the actuarial assumptions. The actuary may either use reasonable, best-estimate assumptions based on the plan’s experience, or use the assumptions and methods in the corporation’s rules. The actuary may use the most recent full actuarial valuation done for section 412 of title 26 and make reasonable estimates for years after that. If full data are missing, the actuary can use whatever data are available or a sampling that represents the whole plan. Unfunded vested benefits means the value of nonforfeitable benefits minus the value of the plan’s assets.

Full Legal Text

Title 29, §1393

Labor, Source: USLM XML via OLRC

(a)Use by plan actuary in determining unfunded vested benefits of a plan for computing withdrawal liability of employer
The corporation may prescribe by regulation actuarial assumptions which may be used by a plan actuary in determining the unfunded vested benefits of a plan for purposes of determining an employer’s withdrawal liability under this part. Withdrawal liability under this part shall be determined by each plan on the basis of— (1)
(2)actuarial assumptions and methods set forth in the corporation’s regulations for purposes of determining an employer’s withdrawal liability.
(b)Factors determinative of unfunded vested benefits of plan for computing withdrawal liability of employer
In determining the unfunded vested benefits of a plan for purposes of determining an employer’s withdrawal liability under this part, the plan actuary may—
(1)rely on the most recent complete actuarial valuation used for purposes of section 412 of title 26 and reasonable estimates for the interim years of the unfunded vested benefits, and
(2)in the absence of complete data, rely on the data available or on data secured by a sampling which can reasonably be expected to be representative of the status of the entire plan.
(c)Determination of amount of unfunded vested benefits
For purposes of this part, the term “unfunded vested benefits” means with respect to a plan, an amount equal to—
(A)the value of nonforfeitable benefits under the plan, less
(B)the value of the assets of the plan.

Legislative History

Notes & Related Subsidiaries

Editorial Notes

Amendments

1989—Subsec. (b)(1). Pub. L. 101–239 substituted “Internal Revenue Code of 1986” for “Internal Revenue Code of 1954”, which for purposes of codification was translated as “title 26” thus requiring no change in text.

Statutory Notes and Related Subsidiaries

Effective Date

of 1989 AmendmentAmendment by Pub. L. 101–239 effective, except as otherwise provided, as if included in the provision of the Tax Reform Act of 1986, Pub. L. 99–514, to which such amendment relates, see section 7891(f) of Pub. L. 101–239, set out as a note under section 1002 of this title.

Reference

Citations & Metadata

Citation

29 U.S.C. § 1393

Title 29, Labor

Last Updated

Sep 22, 2026

Release point: 119-110