Medicare Set-Aside Arrangements in Workers' Compensation Settlements

Medicare Set-Aside Arrangements (MSAs) represent one of the most consequential compliance obligations in workers' compensation settlement practice, governing how future injury-related medical costs must be allocated before Medicare's secondary payer obligations attach. Federal statute requires that Medicare's interests be "considered and protected" in any settlement that resolves ongoing medical liability, and failure to properly structure an MSA can expose both the injured worker and the settling employer or insurer to significant federal repercussions. This page covers the definition, structural mechanics, classification rules, and common misconceptions surrounding workers' compensation MSAs, drawing on publicly available CMS guidance and relevant federal statutes.

• Definition and scope
• Core mechanics or structure
• Causal relationships or drivers
• Classification boundaries
• Tradeoffs and tensions
• Common misconceptions
• Checklist or steps (non-advisory)
• Reference table or matrix

Definition and scope

A Medicare Set-Aside Arrangement is a financial tool used within workers' compensation settlements to segregate a portion of the settlement proceeds specifically designated for future medical expenses that would otherwise be covered by Medicare for the injured worker's compensable condition. The legal foundation is the Medicare Secondary Payer (MSP) statute, codified at 42 U.S.C. § 1395y(b), which establishes Medicare as a secondary payer when another entity — such as a workers' compensation insurer — has primary payment responsibility.

The Centers for Medicare & Medicaid Services (CMS) administers the MSP program and has issued policy guidance through its Workers' Compensation Medicare Set-Aside Arrangements (WCMSA) reference guide, most recently updated as Version 3.9 (April 2023). CMS does not operate a statutory mandate requiring MSA submission or approval for every settlement, but the agency does maintain a voluntary review threshold program: as of the Version 3.9 guidance, CMS reviews cases where the claimant is a Medicare beneficiary or has a "reasonable expectation" of Medicare enrollment within 30 months, and the total settlement value equals or exceeds $25,000, or where the claimant is not yet a Medicare beneficiary but the total settlement exceeds $250,000 (CMS WCMSA Reference Guide, §4.1).

The scope of an MSA is limited to future medical expenses for the work-related injury or illness — not future lost wages, not unrelated medical conditions, and not past medical expenses already paid or liened. This boundary is frequently misunderstood by settling parties.

Core mechanics or structure

Structurally, an MSA functions as a ring-fenced allocation within the broader settlement. Once the settlement is finalized and the MSA is funded, the designated funds must be exhausted on Medicare-covered, injury-related medical expenses before Medicare will pay as the secondary payer for those same services.

Funding methods. CMS recognizes two primary funding structures:

1. Lump-sum — The full projected MSA amount is deposited at settlement into a dedicated, interest-bearing account. Medicare does not pay for injury-related care until the account balance is depleted.
2. Structured/annuity-funded — An upfront "seed" amount is deposited, with periodic annuity payments to replenish the account over the claimant's life expectancy. CMS calculates the rated age of the claimant (often using insurer-provided life expectancy tables) when reviewing structured MSA proposals.

Administration. The claimant may self-administer the account or engage a professional administrator. CMS requires annual attestation that funds were spent appropriately. Supporting documentation — receipts, Explanation of Benefits records, pharmacy invoices — must be retained. The CMS WCMSA Reference Guide, §17 specifies reporting obligations and attestation formats.

Professional administration. When the MSA account contains funds exceeding approximately $25,000 at inception or when the claimant is a Medicare beneficiary with limited capacity to manage funds, professional administration is frequently used, though CMS does not universally mandate it. Administrators file annual attestations and maintain ledger records by service type — pharmacy, physician visits, durable medical equipment — tracking against the approved allocation.

Causal relationships or drivers

The MSA obligation is triggered by the intersection of three independent variables: Medicare beneficiary status (or projected status), the existence of an ongoing medical component in a workers' compensation claim, and a settlement that closes or limits the insurer's future medical liability.

The MSP statute was enacted in 1980 as part of the Omnibus Reconciliation Act (P.L. 96-499) and was substantially strengthened by the Medicare, Medicaid, and SCHIP Extension Act of 2007 (MMSEA, P.L. 110-173), which added mandatory insurer reporting requirements through Section 111. Section 111 reporting compels group health plans, liability insurers, no-fault insurers, and workers' compensation carriers to report settlement data to CMS, giving the agency visibility into cases that might otherwise escape scrutiny.

The aging of the U.S. workforce is structurally relevant: workers injured later in their careers are more likely to be Medicare-eligible (age 65+) or Social Security Disability Insurance (SSDI) recipients who qualify for Medicare after a 24-month waiting period. A claimant who becomes eligible for SSDI after a severe work injury can enter Medicare much earlier than age 65, expanding the pool of cases requiring MSA analysis. The Social Security Administration's SSDI program provides the eligibility pathway that makes this timing variable critical in settlement planning.

The presence of opioid pain management or high-cost biologics in the treating regimen also drives MSA dollar amounts upward, since the projected MSA must account for the expected cost of Medicare-covered medications over the claimant's rated life expectancy.

Classification boundaries

Not all workers' compensation settlements require an MSA, and not all MSAs require CMS submission. The classification framework has three layers:

Layer 1 — Threshold analysis. CMS voluntary review thresholds (§4.1 of the WCMSA Reference Guide) define when submission is appropriate. Below-threshold settlements may still carry MSP compliance obligations but fall outside the formal CMS review program.

Layer 2 — CMS-approved vs. non-submitted MSAs. A settlement can include an MSA without submitting it to CMS for approval. CMS takes the position that a non-submitted MSA does not carry the same safe harbor protection as an approved arrangement. The agency explicitly states in the Reference Guide that CMS-approved amounts provide "assurance" that Medicare's interests are protected, whereas unapproved allocations may be subject to later challenge.

Layer 3 — Zero-dollar MSAs. In cases where future Medicare-covered injury-related treatment is not expected (e.g., the claim is medically stable and no further treatment is anticipated), a documented zero-dollar MSA may be appropriate. This requires a factual record supporting the conclusion — typically a physician attestation or structured report. The CMS WCMSA Reference Guide, §4.3 addresses these scenarios.

For a broader view of how settlements interact with other medical cost management functions, the workers' comp settlement services and workers' comp medical management pages provide relevant structural context.

Tradeoffs and tensions

The MSA process generates genuine conflicts of interest and contested interpretive questions that practitioners regularly navigate.

Adequacy vs. over-allocation. CMS reviewers tend to project conservative (high) treatment costs using Medicare fee schedules, which can produce MSA amounts larger than the claimant might realistically spend. An over-allocated MSA may consume funds the claimant anticipated for wage replacement or other needs — effectively reducing the economic value of the settlement without a corresponding Medicare benefit.

Voluntary vs. non-submission. Submitting to CMS for approval provides a degree of safe harbor but adds time — typically 4–6 months for a standard review under CMS's current workload — and CMS may counter-propose a higher allocation than the parties calculated. Settling without submission is faster but leaves open the risk that CMS later asserts the MSA was inadequate and refuses to pay as secondary payer.

Re-review and amended submissions. If a claimant's medical status changes materially before settlement is finalized, CMS allows re-review. However, re-review restarts the clock and adds cost. This tension between finality and accuracy is particularly acute in complex spinal injury cases involving anticipated surgical intervention.

Structured funding and insurer solvency. Annuity-funded MSAs depend on the continued solvency of the annuity issuer. If the annuity provider becomes insolvent, the state guaranty mechanism provides limited protection, typically capped at $250,000–$500,000 depending on state statute — a coverage ceiling that may be insufficient for long-duration, high-cost MSAs. The National Organization of Life & Health Insurance Guaranty Associations (NOLHGA) coordinates the multi-state response to insurer insolvencies.

For context on how insurers structure financial risk tools in this space, see the workers' comp excess and reinsurance overview.

Common misconceptions

Misconception 1: CMS approval is legally required for every settlement.
CMS approval is voluntary, not mandatory. The MSP statute imposes a duty to protect Medicare's interests; the CMS review program is one mechanism for demonstrating compliance, but it is not the only mechanism. The agency's own WCMSA Reference Guide (§1.0) acknowledges the voluntary nature of the submission process.

Misconception 2: An MSA only applies if the claimant is currently on Medicare.
The "reasonable expectation" standard encompasses claimants who are not yet Medicare beneficiaries but who have applied for SSDI or have a condition likely to qualify them within 30 months. Ignoring this forward-looking test is a documented source of MSP exposure.

Misconception 3: Once CMS approves an MSA amount, that amount can never be challenged.
CMS has reserved the right to reopen approved cases if material misrepresentation is found. Additionally, CMS approval addresses its program interests — it does not create res judicata against other federal or state agencies with independent lien rights, such as Medicaid administered under the state's 42 U.S.C. § 1396p authority.

Misconception 4: The MSA account can be used for any medical expense.
MSA funds are restricted to Medicare-covered, injury-related services. Using MSA funds for non-covered services (e.g., experimental treatments not covered by Medicare, or treatment of unrelated conditions) constitutes improper administration and can result in CMS refusing secondary payer coverage until a properly calculated amount is re-spent.

Misconception 5: Professional administration eliminates all compliance risk.
Professional administrators reduce operational risk but do not absorb legal risk from an improperly calculated MSA. The adequacy of the allocation is a separate question from the quality of administration.

The workers' comp lien resolution page addresses the related but distinct question of resolving existing Medicare and Medicaid liens prior to settlement.

Checklist or steps (non-advisory)

The following sequence reflects CMS-documented process elements as described in the WCMSA Reference Guide. This is a structural reference, not legal or professional advice.

Phase 1 — Pre-settlement eligibility determination
- [ ] Confirm whether the claimant is a current Medicare beneficiary (Part A and/or Part B enrollment)
- [ ] Assess whether the claimant has applied for SSDI or has a condition likely to produce Medicare eligibility within 30 months
- [ ] Verify current claim status: is future medical liability open or being closed by settlement?

Phase 2 — Settlement threshold analysis
- [ ] Calculate total settlement value against CMS voluntary review thresholds ($25,000 for current Medicare beneficiaries; $250,000 for claimants with reasonable expectation)
- [ ] Determine whether a formal CMS submission is appropriate based on threshold analysis

Phase 3 — MSA allocation development
- [ ] Obtain treating physician documentation of anticipated future treatment needs
- [ ] Develop a draft MSA allocation using Medicare fee schedules for the claimant's geographic region
- [ ] Determine rated age (for structured/annuity-funded arrangements)
- [ ] Choose between lump-sum and structured funding based on case economics

Phase 4 — CMS submission (if applicable)
- [ ] Compile submission package per CMS WCMSA Reference Guide §10: medical records, settlement agreement draft, MSA proposal, rated age documentation
- [ ] Submit via CMS's Workers' Compensation Set-Aside Portal (WCSA Portal)
- [ ] Track review timeline; respond to any CMS development requests within the specified 30-day window

Phase 5 — Account establishment and ongoing administration
- [ ] Open a dedicated, interest-bearing MSA account
- [ ] Enroll in professional administration if appropriate
- [ ] Establish annual attestation schedule aligned with CMS's reporting cycle
- [ ] Retain all receipts, EOBs, and pharmacy records by service category

Reference table or matrix

WCMSA Classification and Submission Decision Matrix

MSA Funding Structure Comparison

The relationship between MSA structure and overall workers' comp claims management services affects how carriers budget reserve allocations and close claims files on a jurisdictional basis.

References

• Centers for Medicare & Medicaid Services — WCMSA Reference Guide (Version 3.9, 2023)
• 42 U.S.C. § 1395y(b) — Medicare Secondary Payer Statute (Cornell Legal Information Institute)
• [Medicare, Medicaid, and SCHIP Extension Act of 2007 (MMSEA), P.L. 110-173 — Congress.gov](https://www.congress.