What a Medicare set-aside actually is
CMS — the federal agency that runs Medicare — defines a Workers' Compensation Medicare Set-Aside Arrangement as "a financial agreement that allocates a portion of a workers' compensation settlement to pay for future medical services related to the workers' compensation injury, illness, or disease." That one sentence is the whole concept. Part of your settlement money gets set aside, in its own account, to pay for the future injury care that Medicare would otherwise be billed for. And "these funds must be depleted before Medicare will pay for treatment related to the workers' compensation injury, illness, or disease."
Why does this exist? Because Medicare is, by federal statute, a secondary payer. Under the Medicare Secondary Payer law, 42 U.S.C. § 1395y(b), and its regulations at 42 CFR Part 411, workers' comp pays first for work-injury care and Medicare pays second — if at all. When you settle a claim and take money for future medical care, that money is supposed to actually pay for that care. The set-aside is simply the bookkeeping that proves it did. Every fact in this article is dated: it reflects CMS's WCMSA Reference Guide, Version 4.6, published July 13, 2026, and the CMS pages current as of this writing.
An MSA is one of the scariest-sounding things that can appear in settlement paperwork. It has its own acronym soup — WCMSA, MSP, Section 111, attestation — and an entire vendor industry with an incentive to make it sound complicated. Our job here is to make it boring. Boring is achievable, because the rules are fewer and simpler than the paperwork suggests. Where the MSA number fits inside your total settlement is covered in the settlement chart article; this one explains the set-aside itself.
When an MSA is not your problem
Start with the exits, because for many readers this whole topic is moot.
You're not on Medicare and won't be soon
Not a beneficiary, no Social Security Disability application pending, nowhere near enrollment? There's no reasonable expectation of Medicare within 30 months, and Medicare's interest in your future care is remote. Settle normally — MSAs live where Medicare and settlements collide.
A pending or appealed SSDI application changes the answer — it's the classic trigger for the 30-month test. Tell your lawyer about it before anyone sizes a settlement.
Your settlement leaves medical benefits open
A set-aside replaces future medical benefits you're closing out. If your settlement resolves only wage-loss money and leaves medical open — which some states allow — the insurer keeps paying for injury care, Medicare stays secondary the ordinary way, and there's nothing to set aside.
Open medical means the comp insurer stays primary for injury care. The MSA question only appears the day you consider closing medical for money.
You're a beneficiary settling for $25,000 or less
CMS won't review a proposal below its threshold, so no formal submission is available or expected. Keep the settlement's medical allocation documented and use it for injury care first.
Below-threshold is not a free pass — Medicare still can't be billed for care your settlement money was meant to cover. It just means no CMS review process exists for you.
You're closing medical at real money, on or near Medicare
On Medicare and settling above $25,000, or expecting Medicare within 30 months on a settlement above $250,000? This is the lane the rest of this article covers. Read it, then run the Before You Sign checklist before any paperwork.
Done right, the set-aside is protection, not a tax: your future injury care gets paid, and Medicare picks up the bill for good once the account is properly spent.
It generally means concrete facts: you've applied for Social Security Disability benefits, been denied and are appealing, are 62 years and 6 months old or older, or have end-stage renal disease. If none of those describe you, the 30-month test usually isn't met. Terms like beneficiary and MSP are defined in the glossary.
The biggest misconception: "the MSA is required by law"
Here is the sentence that should reframe this whole subject, quoted from Section 1.0 of CMS's own WCMSA Reference Guide: "There are no statutory or regulatory provisions requiring that you submit a WCMSA amount proposal to CMS for review." CMS's website calls submission "a recommended process." Not mandatory. Recommended.
So why does everyone at the settlement table act like the MSA is federal law? Because two different things are getting collapsed into one. Protecting Medicare's interests is a real legal duty. The MSP statute makes Medicare secondary to workers' comp, and Medicare cannot lawfully be billed for injury care that your settlement was funded to cover. Submitting an MSA proposal to CMS for review is voluntary. It's the standard way parties prove they took the duty seriously — an approved amount is a green light from the agency itself — but no statute or regulation compels it.
This distinction is worth money and worth calm. It means an MSA in your settlement papers is not the government reaching into your pocket — it's your own settlement money, still yours, earmarked so that your future care gets paid without breaking federal billing rules. And it means the real questions are practical: how big should the set-aside be, should the parties ask CMS to bless the number, and who manages the account afterward. Those are the questions the rest of this article answers.
The $25,000 and $250,000 review thresholds
CMS will not review every proposal. It set two workload thresholds, and a settlement must fit one of them for review to even be available.
| Situation | Will CMS review a proposal? | What it means for you |
|---|---|---|
| You are a Medicare beneficiary and the total settlement is greater than $25,000 | Yes — threshold A is met | The parties can submit the proposed set-aside through CMS's WCMSA Portal and get an approved amount. Most reviewed cases travel this lane. |
| You reasonably expect Medicare enrollment within 30 months and the anticipated total settlement — future medical plus disability or lost-wage money over the life or duration of the agreement — is expected to exceed $250,000 | Yes — threshold B is met | Review is available even though you're not on Medicare yet. The 30-month test usually turns on an SSDI application or appeal, age 62½+, or end-stage renal disease. |
| You are a beneficiary but the settlement is $25,000 or less | No — below the workload threshold | CMS won't look at it. This is not a safe harbor: money designated for future injury care must still be used for that care before Medicare is billed. |
| You are not a beneficiary and don't meet the 30-month/$250,000 test | No | No review available, and generally no MSA machinery either. Medicare's interest in your case is remote. |
| A proposed set-aside amount of $0, on or after July 17, 2025 | No — CMS stopped accepting zero-dollar proposals | The old route of asking CMS to confirm that no set-aside was needed is closed. Parties document their reasoning themselves. |
Read the table's third row twice, because it kills the second-biggest myth in this area: "under $25,000, Medicare doesn't care." The thresholds are CMS describing its own workload — which proposals it will spend reviewer time on — not an exemption from the secondary-payer law. Below the thresholds there's no review to request, but the underlying rule is unchanged: settlement money meant for future injury care pays for that care first. In practice, small settlements handle this with proportionally small, informal allocations and receipts, not a formal CMS process.
If review is voluntary, why does anyone volunteer? Certainty. A CMS-approved amount is the agency agreeing, in writing, that this much money protects its interests — spend it properly and Medicare pays primary afterward, with no argument about whether the number was big enough. That certainty costs time: CMS review is one of the genuine reasons settlements slow down, covered honestly in how long settlements take.
What changed in 2025 — and why "just skip it" got riskier
For years, some settlements handled the MSA question quietly: fund a modest "evidence-based" set-aside from a vendor, never tell CMS, and rely on the fact that nobody was checking. Three dated changes closed most of that road.
None of this makes MSAs mandatory — the Guide's Section 1.0 sentence still stands. What it changes is the risk math of cutting corners. An honestly sized set-aside, submitted or not, remains fine. A deliberately skinny one is now reported to CMS automatically and carries a written warning that the entire net settlement could stand between you and Medicare coverage. If a settlement offer you're reviewing leans on a bargain non-submit MSA, that's a question for the Before You Sign checklist — and possibly for a lawyer.
A settlement document that makes you responsible for "protecting Medicare's interests" while allocating suspiciously little to do it. If CMS later treats the MSA as underfunded burden-shifting, the denial lands on your medical care — not on the insurer who saved money at signing. Ask how the MSA number was calculated and by whom, in writing, before you sign.
A worked example: $100,000 settlement, $30,000 set-aside
A 58-year-old warehouse worker in Ohio settles her back-injury claim for $100,000 total. She's a Medicare beneficiary, and $100,000 is greater than $25,000, so CMS review is available if the parties want it. Her doctors project future Medicare-covered, injury-related care — pain-management visits, injections, medications — at $30,000 over her life expectancy. The numbers here are round and illustrative, not typical values; there is no "normal" MSA size.
Walk it through. At settlement, $30,000 goes into a separate interest-bearing account. She keeps the remaining $100,000 − $30,000 = $70,000 — indemnity money and everything non-Medicare, less attorney fees and costs under Ohio's rules. Each year she pays injury-related, Medicare-covered bills from the account, keeps the receipts, and files an attestation with CMS. If she spends about $2,500 a year, the $30,000 lasts roughly $30,000 ÷ $2,500 = 12 years. When the last properly documented dollar is spent, Medicare pays primary for her injury care from then on — permanently. How Ohio handles the settlement side of a claim is in the Ohio guide; every other state is in the state index. Note the MSA rules themselves are federal — they don't change at state lines, even though settlement procedure does.
Two things this example should defuse. First, the MSA didn't shrink her settlement — the $30,000 was always the future-medical part of the number; the account just fences it. Whether the total number itself is fair is a different question, sized in the settlement chart and the settlement estimator. Second, the money isn't lost if she stays healthy — it sits in her account, earning interest, spendable on her injury care for as long as she needs it, and after proper exhaustion Medicare takes over.
How the account works day to day
Once funded, an MSA is mostly a bookkeeping routine. The rules, from Section 17 of the Reference Guide and CMS's self-administration materials, come down to four.
One account, separate and interest-bearing. The set-aside money goes in its own interest-bearing account — not your checking account, not mixed with the rest of the settlement. Interest earned belongs to the account and gets spent on the same things the principal does.
Spend it on exactly one category. The account pays for care that is both Medicare-covered and related to the work injury. Both tests must pass. Injury-related care Medicare doesn't cover — and unrelated care Medicare does cover — comes from other money. Your unrelated knee replacement is Medicare's job as usual; your injury-related massage therapy that Medicare wouldn't cover isn't the account's job either.
Keep records and attest annually. The administrator keeps itemized records of every payment and submits an annual attestation to CMS confirming the money was spent correctly — electronic attestation is available. This isn't busywork; it's the paper trail that later proves proper exhaustion.
Exhaust it properly and Medicare takes over. Once the approved amount is appropriately spent and accounted for, the Guide is explicit: Medicare will pay primary for future Medicare-covered expenses related to the injury. The account is a bridge with a far bank, not a cliff.
Spending MSA money on anything else — rent, a car, unrelated medical bills. Misspent funds don't count toward exhaustion, and Medicare can refuse to pay for your injury care until the full approved amount is properly accounted for. The account is not scary; raiding it is. If bills are squeezing you, the answer is anything but this account.
Who does this bookkeeping? Three options are recognized: you (self-administration), a representative payee, guardian, or conservator on your behalf, or a professional administrator. Self-administration is free and genuinely manageable for a simple, stable care routine — CMS publishes a self-administration toolkit for exactly this. A professional administrator charges a fee (pricing varies; there's no official schedule, so shop) and earns it when the medical picture is complicated: many providers, frequent pricing questions, or a structured MSA with annual deposits to track. Neither choice is legally superior. Pick for your paperwork tolerance.
Lump sum vs. structured: two ways the money runs out
An MSA can be funded all at once or as an annuity, and the exhaustion rules differ in a way worth understanding before you pick.
Lump-sum MSA. The whole amount — $30,000 in our example — is deposited at settlement. Exhaustion is permanent and one-way: when the last properly documented dollar is gone, Medicare pays primary for injury care forever after. Simple, one account, one finish line.
Structured MSA. An initial deposit at settlement, then annual deposits — in our Ohio example, say $8,000 up front as a first-surgery cushion plus seed money, then $2,000 a year for 11 years: $8,000 + 11 × $2,000 = $30,000. The interesting rule is temporary exhaustion: if a bad year costs $3,500 and the available funds run out mid-year, Medicare pays primary for the rest of that year, then the MSA resumes when the next annual deposit lands. Unspent money in good years carries forward.
The trade is intuitive. A lump sum gives you the whole fund immediately and one clean finish line, but a catastrophic early year spends years of budget at once. A structure smooths the money and hands Medicare the tail risk of expensive years — at the cost of more bookkeeping and deposits arriving on the annuity's schedule rather than yours. One neighboring fact readers always ask about together: workers' comp settlement money is generally not taxable income, though the interest an MSA account earns raises its own questions — the taxability article sorts it out.
If your care changes later: the amended review
An approved MSA is a projection, and projections miss. Maybe the fusion surgery priced into your set-aside never happens; maybe a condition worsens and the number is suddenly too small. For CMS-approved cases, there's a mechanism: the amended review.
The current rules, as of April 7, 2025: a case with a CMS-approved amount may request one amended review, at any time after approval — the old waiting period is gone. The projected care must have changed enough that the new calculation moves the approved amount by 10% or $10,000, whichever is greater. One shot per case: a case that already had an amended review, or had a request denied, can't ask again. Requests go through the same WCMSA Portal the original submission used.
For years the rule was that amended review was only available in a window starting 12 months after approval, and earlier still there was an outer time cap. Both are gone — since April 7, 2025 the request can come anytime after approval. Any page still describing a waiting period is describing a dead rule. This is also a reason to date-check everything you read about MSAs, including this page: our facts are current to Reference Guide v4.6, July 13, 2026.
Because it's one-per-case, timing is strategy. Burn your amended review on a modest change and a bigger change later has no mechanism. That single decision — when to spend a once-per-case request — is the kind of question worth a professional's judgment; the do-I-need-a-lawyer tool is honest about when you do and don't need one.
The four costly MSA mistakes
Workers hear "set-aside" and negotiate as if that slice is gone. It isn't — it's your money, fenced for your care, earning interest, with Medicare stepping in when it's properly spent. The negotiation question is whether the total settlement is right, not whether an MSA exists.
Since April 4, 2025 CMS sees the number whether or not it was submitted, and Guide 4.3 says an underfunded non-approved MSA can cost you Medicare coverage until the entire net settlement is exhausted. Ask who calculated it and how, in writing.
Improper spending doesn't count toward exhaustion, and the annual attestation is your proof. A shoebox of receipts and a once-a-year filing is the entire job — skipping it is how a healthy account turns into a Medicare denial.
One per case, ever, and a denied request bars another. If your care picture is still moving, the 10%-or-$10,000 change you can prove today may be dwarfed by the one you could prove next year.
And the honest flip side: many people need no help with any of this. If you're below the review thresholds, or self-administering a small, stable account with one clinic and a pharmacy, the CMS toolkit and a folder of receipts are genuinely enough. Where advice earns its cost is at the settlement table — sizing the set-aside, deciding whether to submit, choosing lump sum versus structure — because those choices are hard to unwind after signing. Timing matters too: MSA preparation and optional CMS review are among the honest reasons a settlement takes longer, mapped in how long settlements take. Reaching maximum medical improvement first is usually what makes the future-care projection credible at all.
Frequently asked questions
How the set-aside was sized, whether to submit it to CMS, and lump sum versus structure are decisions that are hard to unwind after signing. Consultations are free, and the settlement documents plus this page are most of what a lawyer needs to see.
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