Written by Jessica Miller · Published November 12, 2026 · Last reviewed November 12, 2026
Medicare coverage for affected noncitizen enrollees ends no earlier than February 1, 2027. SSA mails the notices, and each patient's end date is on their termination notice. Providers should keep checking eligibility in HETS for every Medicare patient as of each date of service, using existing procedures.
| Figure | Number | What it means in practice |
|---|---|---|
| Earliest first day without Medicare | February 1, 2027 | Applies to the grace-period group. Patients identified later lose coverage at the end of the month after their notice month. |
| SSA preliminary notices (SSA estimate) | About 300,000, November 2026 | These are notices, not terminations. People who get one can still submit documentation. |
| People projected to lose coverage (CMS Office of the Actuary) | About 32,000 | CMS says the actual number remains unknown. |
| SSA reconsideration window | 60 days | Good cause can extend it. Coverage does not continue during the appeal. |
| Special enrollment period | 12 months | Starts the first day of the month the person contacts SSA and provides sufficient evidence that they meet the requirements, and ends the last day of the 12th month after that month. A patient-enrollment fact, not a billing rule. |
Sources: CMS's CY 2027 Physician Fee Schedule final rule , section III.E, and MLN Connects, November 12, 2026 .
What changed in Medicare eligibility, and who stays eligible?
Some of your Medicare patients will lose coverage in 2027, and the first sign at registration may be an eligibility response with no active Part A or Part B.
The change comes from section 71201 of Public Law 119-21 (H.R. 1, enacted July 4, 2025), which CMS calls the Working Families Tax Cut legislation. It added Social Security Act section 1899C ( 42 U.S.C. 1395mmm ), which limits Medicare entitlement and enrollment to four groups, who must also meet Medicare's other eligibility rules:
- A U.S. citizen or national
- A lawful permanent resident (green card holder)
- A Cuban and Haitian entrant
- A person lawfully residing in the U.S. under a Compact of Free Association (CMS shorthand: COFA migrant)
Not every green card holder qualifies: the 5-year continuous residency requirement for lawful permanent residents enrolling in premium Part A or Part B still applies.
The law narrows eligibility from the broader "lawfully present" standard in 8 CFR 1.3(a). CMS's examples of previously eligible categories outside the four groups are asylees, refugees, and people paroled into the U.S. for at least one year. People who were not lawfully present were already ineligible. CMS implemented the law in the CY 2027 Physician Fee Schedule final rule (CMS-1848-F, 91 FR 70992, published November 9, 2026, effective January 1, 2027).
When does Medicare coverage actually end for affected patients?
People entitled to or enrolled in Medicare as of July 4, 2025 got an 18-month grace period. The statutory date is January 4, 2027, but Medicare entitlement ends on the last day of a month, so CMS set termination for this group effective February 1, 2027: coverage runs through January 31. Secondary FAQs that say coverage ends "no later than January 4, 2027" do not match the final rule.
February 1 is the earliest end, not one cliff for everyone. SSA planned preliminary notices for November 2026 and termination notices with appeal rights for December 2026, and CMS adds a courtesy notice with taglines in 14 languages. Patients identified later lose coverage at the end of the month after their notice month: a March 2027 notice means termination at the end of April 2027. For people not entitled to or enrolled in Medicare as of July 4, 2025, the limit has applied since enactment.
Terminations run forward only. CMS "will take no action to recover any Medicare payments for services rendered before the individual's prospective termination." Coverage does not continue during an SSA appeal.
What should patient access teams check in HETS?
CMS made no HETS changes for this law; providers "should continue to use this system to verify Medicare eligibility using existing procedures." HETS reports entitlement, not immigration status, and CMS has documented no new eligibility codes.
A 271 response is not a promise that Medicare will pay. The HETS 270/271 Companion Guide says its data is accurate only at the time of the transaction, and payment stays subject to all other benefit rules.
Recommended practice, not a CMS mandate:
- Run a routine HETS query for every Medicare patient as of the date of service, not a one-time February 1 sweep.
- Recheck close to the visit, and keep the 271 with the claim.
- If coverage has ended or a patient brings an SSA letter, offer financial counseling and point them to SSA, and to USCIS for immigration records.
- Do not screen patients by perceived immigration status, and do not cancel scheduled care automatically.
Medicare Advantage works differently. CMS, not the plan, disenrolls MA and Part D members through MARx after SSA updates its records, effective the first day of the month after the plan receives CMS's notice. Plans may send members a disenrollment notice but are not required to. The MLN item says MA organizations will inform their providers, and MLN8816413 tells you to direct MA eligibility questions to the plan named in the HETS response. A WISeR provisional affirmation also still needs Medicare eligibility on the date of service.
Is a denial after Medicare coverage ends a coding error?
No. A claim for a date of service after Medicare ends is an eligibility problem, and recoding will not fix it. The generic X12 code for it is CARC 27 , "Expenses incurred after coverage terminated." No CMS source we found names the code or edit Medicare will use for these terminations, so treat CARC 27 as generic, not a confirmed CMS edit. Route these claims to patient access. Our guides to CARC codes and coding denials help keep the two queues apart.
Eligibility decides who pays. MediCodio AI does not verify eligibility or query HETS; that work stays with your patient access team. Once coverage is confirmed, the claim still has to be coded from the documentation. Complete charts flow through AutoPilot for fully autonomous coding. Charts where the documentation is thin or contradictory stay in CoPilot, where certified coders review and finalize the output.
Frequently asked questions
Who is still eligible for Medicare under the new law?
Section 1899C of the Social Security Act limits Medicare to U.S. citizens or nationals, lawful permanent residents, Cuban and Haitian entrants, and people lawfully residing under a Compact of Free Association. Lawful permanent residents enrolling in premium Part A or Part B still need 5 years of continuous residency.
When will affected patients lose Medicare coverage?
No earlier than February 1, 2027. People entitled to or enrolled in Medicare as of July 4, 2025 who do not qualify have no Medicare starting that date, after a December 2026 termination notice. People identified later lose coverage at the end of the month after their notice month. The SSA termination notice shows the actual date.
Does HETS show whether a patient is losing Medicare under the new rule?
HETS shows Medicare entitlement dates, not immigration status. CMS made no HETS changes for this law. Check Part A and Part B entitlement for each date of service, and for Medicare Advantage patients, check with the plan named in the response. A 271 response is not a promise of payment.
Will Medicare take back payments for services before termination?
No. CMS says terminations are prospective and it will take no action to recover Medicare payments for services before a patient's termination. Claims for those dates of service process under existing procedures. The date of service decides whether Medicare is the payer.
Does Medicare coverage continue while a patient appeals?
No. Patients can ask SSA for reconsideration within 60 days of the notice, extendable for good cause, but CMS says the law gives it no authority to continue coverage during an appeal. If SSA later finds the patient eligible, coverage can be reinstated retroactively and those claims may be processed.
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Sources
- Public Law 119-21 , Congress.gov
- CY 2027 PFS final rule , Federal Register
- MLN Connects, November 12, 2026 , CMS
- MLN8816413 , CMS
- HETS 270/271 Companion Guide , CMS
- CARC list , X12