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Part 11 · Chapter 1

Multiple Employer Plan Structure, Qualification, and Single-Plan Status

Law stated as of October 3, 2026 · Multiple-Employer and Small-Employer Arrangements

Scope and status

This chapter covers the architecture of a multiple employer plan (MEP): what a MEP is under Code §413(c) and how it differs from a multiemployer plan and from a controlled-group plan; whether the arrangement is one ERISA plan or many; which Code requirements are tested plan-wide and which employer-by-employer; documents, determination letters, and the limits on a participating employer's reliance; Form 5500 and audit consequences; PEO-sponsored arrangements; and 403(b) MEPs. Scope discipline: the §413(e) pooled employer plan (PEP) overlay and pooled plan provider duties are in the PEP chapter; the one-bad-apple rule and participating-employer failures are in the unified plan rule chapter; SEP/SIMPLE and other small-employer vehicles are in the small-employer arrangements chapter. Related questions are treated elsewhere: controlled-group and ASG determinations in Part 1 (Controlled Groups and Affiliated Service Groups); coverage and nondiscrimination mechanics (including ADP/ACP and the §415 limits) in Part 5 (Qualified Plan Testing, Eligibility, and Vesting); and welfare-side multiple-employer arrangements (MEWAs, association health plans) in Part 13 (COBRA, HIPAA, and Welfare Benefits).

Sections

Part A is shown in full. The other sections are listed by title; their text is available to subscribers.

Part A — What a MEP Is, and What It Is Not

A1.The definition and the two arrangements it is constantly confused with

Part 11, ch. 1, § A1

A multiple employer plan is a single plan maintained by two or more employers that are not treated as a single employer under Code §414(b), (c), (m), or (o). Statute: Code §413(c); Final reg: Treas. Reg. §1.413-2; Agency guidance — informal: IRM 7.11.7. It is not a multiemployer plan, which is maintained under one or more collective bargaining agreements to which more than one employer contributes and which satisfies ERISA §3(37)/Code §414(f). Statute: Code §414(f); ERISA §3(37). It is also not a plan covering several related entities: if the employers are aggregated under §414(b)/(c)/(m), they are a single employer and the plan is an ordinary single-employer plan with multiple adopting affiliates — not a MEP at all. Statute: Code §414(b), (c), (m); Agency guidance — informal: IRM 7.11.7.

A2.The threshold ERISA question — one plan or many?

Part 11, ch. 1, § A2

Whether a MEP is a single ERISA-covered plan turns on ERISA §3(5)'s definition of "employer," which reaches a person acting "indirectly in the interest of an employer" and any "group or association of employers acting for an employer." Statute: ERISA §3(5), 29 U.S.C. §1002(5). DOL's long-standing position — reaffirmed for retirement plans in Advisory Opinion 2012-04A — is that the entity maintaining the plan must be tied to the participating employers by genuine economic or representational interests unrelated to the provision of benefits, so a program marketed by a service provider to unrelated employers with no organizational nexus (an "open MEP") is not a single ERISA plan; instead, each adopting employer maintains its own separate ERISA plan. Agency guidance — formal: DOL Adv. Op. 2012-04A (May 25, 2012); Practitioner consensus.

A3.The 2019 Association Retirement Plan rule — the safe-harbor route to single-plan status

Part 11, ch. 1, § A3

DOL's 2019 final rule at 29 C.F.R. §2510.3-55 establishes when a bona fide group or association of employers or a bona fide professional employer organization is an "employer" under ERISA §3(5) and may therefore sponsor a single defined contribution MEP. Final reg: 29 C.F.R. §2510.3-55; 84 Fed. Reg. 37508 (July 31, 2019). A bona fide group or association must: (1) have a substantial business purpose unrelated to benefits (offering the plan may be its primary purpose, but it must be viable without it); (2) consist of employers each of which directly employs at least one plan participant; (3) have a formal organizational structure with a governing body and bylaws; (4) be controlled by its employer members; (5) satisfy commonality of interest — same trade, industry, line of business, or profession, or principal place of business in the same State or metropolitan area (which may span State lines); (6) limit participation to employees and former employees of members and their beneficiaries; and (7) not be a bank, insurer, broker-dealer, recordkeeper, or other financial-services firm (or owned or controlled by one), except in its capacity as an employer member. Final reg: 29 C.F.R. §2510.3-55(b)(1)–(2). The rule also recognizes working owners without common-law employees as both employers and employees for this purpose, using an hours test (≥20/week or ≥80/month) or, alternatively, income from the trade or business at least equal to the working owner's cost of coverage under a group health plan sponsored by the group or association. Final reg: 29 C.F.R. §2510.3-55(d).

A4.The welfare-side analogue, and why it is not covered in this Part

Part 11, ch. 1, § A4

The same §3(5) analysis on the welfare side produces a MEWA (ERISA §3(40)), with its own Form M-1 filing, State insurance regulation, and fully-insured/self-insured distinctions. Statute: ERISA §3(40), §514(b)(6). DOL's 2018 association health plan rule (29 C.F.R. §2510.3-5) was held unlawful in substantial part and was subsequently rescinded by final rule. Case law: District — New York v. U.S. Dep't of Labor, 363 F. Supp. 3d 109 (D.D.C. 2019); Final reg: 89 Fed. Reg. 34106 (Apr. 30, 2024) (rescission).

A5.Closed MEPs

Part 11, ch. 1, § A5

A closed MEP — one maintained by employers with a genuine pre-existing relationship (common ownership short of a controlled group, a joint venture and its partners, entities related in form but not aggregated, a genuine trade association) — generally satisfies the commonality analysis of A2/A3 and is the least contested structure. Practitioner consensus; Agency guidance — formal: DOL Adv. Op. 2012-04A (by negative implication).

Part B — Code §413(c): What Is Tested Plan-Wide and What Is Tested Employer-by-Employer

  1. B1The plan-wide requirementsSubscribers
  2. B2The employer-by-employer requirementsSubscribers
  3. B3Mandatory disaggregationSubscribers
  4. B4Defined benefit MEPsSubscribers

Part C — Documents, Determination Letters, and the Limits of Reliance

  1. C1Who applies, and on what formSubscribers
  2. C2The reliance carve-outs — the heart of the matterSubscribers
  3. C3The participation agreement is the operative documentSubscribers

Part D — Reporting, Audit, and the Cost of Getting Single-Plan Status Wrong

  1. D1One filing, plus participating-employer detailSubscribers
  2. D2The audit threshold and the 2023 counting changeSubscribers
  3. D3What goes wrong when an arrangement is not one planSubscribers

Part E — PEO Arrangements

  1. E1The common-law employer problemSubscribers
  2. E2The IRS relief and the MEP conversion pathSubscribers
  3. E3The bona fide PEO route to single-plan statusSubscribers
  4. E4The CPEO trapSubscribers

Part F — Plan Types Beyond the Qualified DC MEP

  1. F1403(b) MEPs and PEPsSubscribers
  2. F2Governmental and church plansSubscribers

The first Part of each chapter is open to everyone. The remaining sections, with their authority and practice points, are available to subscribers and to clients of ERISA Benefits Law Group, PLLC whose engagement includes access.

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