The number that determines the client's net
When a workers' compensation claim settles future medical treatment, Medicare's interests come into the room whether the parties invite them or not. The Medicare Secondary Payer statute says Medicare should not pay for care that a comp settlement was meant to cover. The mechanism that keeps Medicare secondary is the Workers' Compensation Medicare Set-Aside, a carved-out portion of the settlement earmarked to pay future injury-related treatment that Medicare would otherwise cover. Get the set-aside wrong and you either erode the client's net for no reason or expose them to a denial of care down the road.
The set-aside is not a tax and not a lien. It is the client's own money, sequestered and spent first on covered treatment before Medicare picks up the balance. Understanding that framing matters, because the entire negotiation is really about how large that sequestered pool has to be.
When CMS will actually review
The Centers for Medicare and Medicaid Services publishes workload review thresholds, not legal safe harbors, and the distinction trips up practitioners constantly. CMS will review a proposed set-aside only when the claimant is already a Medicare beneficiary and the total settlement exceeds $25,000, or when the claimant has a reasonable expectation of Medicare enrollment within 30 months and the total settlement exceeds $250,000. The current WCMSA Reference Guide, updated to Version 4.6 in July 2026, restates those figures in Section 8.1.
Here is the point most often missed. Falling below the thresholds does not mean Medicare's interests can be ignored. It means only that CMS will not formally review the number. The Secondary Payer obligation still applies. A settlement under $25,000 for a beneficiary still needs a defensible allocation, it just will not carry CMS's stamp. Treating the threshold as permission to skip the analysis is how firms end up with clients whose future claims get denied.
The zero set-aside, used carefully
Sometimes the right number is zero. Where the treatment is denied as non-industrial, where the claim is genuinely disputed on compensability, or where the treating physician documents that no further injury-related care is anticipated, a zero or nominal set-aside can be appropriate. CMS has grown more skeptical of these submissions, and recent Reference Guide updates signal closer scrutiny of proposals that claim no future exposure. The defensible zero is built on contemporaneous medical records and a clear compensability dispute, not on optimism. Document the basis before you propose it.
Funding and administration
Once the amount is set, structure it deliberately:
- Lump sum versus structured. A set-aside can be funded in a single payment or seeded with an initial deposit and replenished by an annuity. Structured funding usually lowers the total the defendant must commit, because CMS credits the annuity stream, which can free room elsewhere in the settlement.
- Self-administration versus professional. Clients may administer the account themselves, but the record-keeping and annual-attestation duties are unforgiving, and mistakes jeopardize future Medicare eligibility. Professional administration costs money but protects the client and the firm.
- Amended review. Where treatment projections change materially after a CMS-approved number, the amended-review process allows a revised submission within defined windows. Calendar it rather than discovering the option too late.
Where it meets the third-party case
The set-aside rarely lives in isolation. When the same injury supports a third-party liability claim alongside the comp file, the set-aside sits next to the comp carrier's lien and credit rights, and the sequencing of those recoveries drives the client's actual net. A larger set-aside reduces cash to the client today, and an aggressive comp credit reduces it tomorrow. The two have to be modeled together, not in separate silos. Our workers'-compensation coverage has worked through the comp-credit math, and the set-aside is the piece practitioners most often bolt on at the end when it should have been in the model from the start.
Lien resolution runs on the same principle. Medicare's conditional-payment recovery for past treatment is a separate obligation from the set-aside for future care, and both have to be resolved before disbursement. Our lien-resolution coverage details how the past-treatment side is calculated, and the future-care set-aside should be run in parallel with it.
Build it into intake, not the eve of settlement
The recurring failure is timing. Firms treat the set-aside as a closing formality and discover late that the number swallows a chunk of the settlement they already promised the client. The fix is procedural. Flag Medicare status and enrollment horizon at intake, order a set-aside allocation early enough to negotiate around it, and price the number into the demand rather than absorbing it at the end. Our practice-operations coverage has made the same point about lien workflows generally: the balances that surprise you at disbursement are the ones you failed to model at the front. The set-aside belongs in that front-end discipline.