Medicare does not expire. Once you qualify and enroll, coverage continues indefinitely; there is no term that runs out and no renewal date on the card. What can happen is that specific events end your coverage, and a few of them catch people by surprise because there’s no long warning period and no easy way back in without penalties.
The situations below are the ones that actually cause Medicare to stop.
What Can Actually End Your Medicare
Missed Premium Payments
This is the most common cause, and the most preventable. Under Original Medicare, the Part B premium bill is due on the 25th of the month, and you have a 90-day grace period before coverage is terminated.1Medicare. How to Pay Part A and Part B Premiums A bill marked “Delinquent Bill” at the top is the final warning.
Medicare Advantage and Part D plans must give you a grace period of at least two full calendar months and send a written notice explaining that you’ll be dropped if you don’t pay by the end of it.2Centers for Medicare & Medicaid Services. What Happens When a Plan Member Doesn’t Pay Their Medicare Plan Premiums? If you pay a Part A premium because you didn’t have enough work history for premium-free coverage, the same rule applies: miss payments and the coverage ends. In 2026, the full Part A premium is $565 per month, or $311 with at least 30 quarters of work credits.3Centers for Medicare & Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles
The ESRD 36-Month Rule After a Transplant
If you qualified for Medicare solely because of end-stage renal disease and you receive a successful kidney transplant, your coverage ends 36 months after the month of the transplant.4Medicare. End-Stage Renal Disease (ESRD) There is no additional grace period once the 36 months are up. If you need another transplant or return to dialysis before that deadline, coverage continues without interruption.
This rule applies only when ESRD is your sole basis for Medicare. If you also qualify based on age or a separate disability, coverage continues on that other basis regardless of the transplant.
Losing Disability-Based Eligibility
If you qualified through Social Security Disability Insurance, your Medicare doesn’t end the moment you return to work. You first go through a nine-month trial work period with full benefits regardless of earnings. After that, Medicare continues for an additional 93 months (about seven years and nine months) as long as your underlying condition still meets Social Security’s disability rules.5Social Security Administration. Q&A on Extended Medicare Coverage That works out to at least eight and a half years of Medicare after you go back to work. Once the extended period ends, you can keep Medicare by paying premiums for both Part A and Part B until you turn 65.6Social Security Administration. Try Returning to Work Without Losing Disability
Moving Out of a Plan’s Service Area
Medicare Advantage and Part D plans operate in specific geographic areas. Move permanently outside that area and the plan must disenroll you.7Centers for Medicare & Medicaid Services. Medicare Advantage Enrollment and Disenrollment Guidance You don’t lose Medicare itself, only that plan. If you’re dropped from a Medicare Advantage plan and don’t sign up for a new one, you go back to Original Medicare.8Medicare.gov. Understanding Medicare Advantage and Medicare Drug Plan Enrollment Periods You get a Special Enrollment Period of two full months after your move to pick a new plan.
Incarceration
Medicare doesn’t technically end when you go to jail or prison, but it stops working. Premium-free Part A entitlement continues on paper, yet Medicare generally won’t pay for medical care while you’re incarcerated.9Centers for Medicare & Medicaid Services. Incarcerated Medicare Beneficiaries Part B still requires premiums, which is complicated because Social Security benefits are usually suspended during custody. Without a direct billing arrangement to keep paying, you lose Part B. Medicare Advantage and Part D plans treat incarceration as being outside the service area and disenroll you the first day of the month after incarceration starts.
After release, if you were released on or after January 1, 2023, you get a 12-month Special Enrollment Period to re-enroll in Part A (if you pay for it) or Part B without late enrollment penalties. You can choose retroactive coverage going back up to six months, though not before the month of release.9Centers for Medicare & Medicaid Services. Incarcerated Medicare Beneficiaries
Voluntary Disenrollment
You can drop Part B, a Medicare Advantage plan, or a Part D plan at any time. People do this when they take an employer plan or move abroad. The risk is on the way back in: limited enrollment windows and permanent premium penalties.
A Note on Citizenship and Residency
Medicare eligibility generally requires U.S. citizenship or lawful permanent residency with at least five continuous years of U.S. residence.10Centers for Medicare & Medicaid Services. Original Medicare (Part A and B) Eligibility and Enrollment A 2025 federal law further restricted eligibility for certain lawfully present immigrants, including people with Temporary Protected Status, refugees, asylees, and those granted humanitarian parole. Official CMS guidance on implementation has been limited. If you fall into one of these categories and previously had Medicare, call 1-800-MEDICARE to check your status.
The COBRA Trap
This is where most costly mistakes happen. If you’re 65 or older and still working with employer health insurance, you can delay Part B without penalty because your employer plan counts as current employment coverage. The day you stop working or lose that employer coverage, an eight-month Special Enrollment Period starts for signing up for Part B.11Medicare.gov. When Does Medicare Coverage Start
COBRA does not count as current employer coverage for Medicare purposes.12Medicare. COBRA Coverage If you elect COBRA after leaving your job and assume it holds off your Medicare deadlines, the eight-month clock is still running from the day your employment or group coverage ended. Miss the window and you wait until the General Enrollment Period (January 1 through March 31), coverage doesn’t start until July, and you pay a 10% Part B penalty for every full year you were eligible but not enrolled.13Medicare.gov. Avoid Late Enrollment Penalties The penalty is permanent. If you’re nearing 65 and about to retire, sign up for Part B when you leave work rather than treating COBRA as a bridge.
What Gaps in Coverage Cost You
Losing or delaying Medicare doesn’t just leave you uninsured for a stretch. It usually makes Medicare permanently more expensive.
Part B Late Enrollment Penalty
For every full 12-month period you could have had Part B but didn’t (without qualifying employer coverage), your monthly premium rises by 10%. The surcharge lasts as long as you have Part B, which for most people is the rest of their life.13Medicare.gov. Avoid Late Enrollment Penalties With the 2026 standard premium at $202.90, someone who delayed enrollment by three years pays an extra $60.87 every month indefinitely.3Centers for Medicare & Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles
Part D Late Enrollment Penalty
Go 63 or more consecutive days without Part D or other creditable prescription drug coverage after you’re first eligible, and you owe an extra 1% of the national base beneficiary premium for every month you went uncovered. The 2026 base premium is $38.99, so 14 months without creditable drug coverage adds about $5.50 per month to your Part D premium for as long as you have it.13Medicare.gov. Avoid Late Enrollment Penalties
Creditable coverage means drug coverage at least as good as a standard Part D plan. Your employer or union plan should send a notice each September stating whether yours qualifies.14Medicare.gov. Notice of Creditable Coverage Keep it. You need that proof if you enroll in Part D later and want to avoid the penalty.
Getting Coverage Back After It Ends
Good Cause Reinstatement
If you were dropped from a Medicare Advantage or Part D plan for non-payment and the reason was genuinely beyond your control, you can request reinstatement under Medicare’s Good Cause policy. The request must come within 60 days of the disenrollment date, and all outstanding premiums must be paid within three months.7Centers for Medicare & Medicaid Services. Medicare Advantage Enrollment and Disenrollment Guidance
Qualifying circumstances include a serious illness or hospitalization through most of the grace period, the death of a spouse or caregiver, severe damage to your home from a fire or natural disaster, or a federally declared emergency. You’ll need a credible explanation. This is a narrow exception for real emergencies, not a routine second chance.
Standard and Special Enrollment Periods
If Good Cause doesn’t apply, you wait for an enrollment period. The Part B General Enrollment Period runs January 1 through March 31, with coverage starting the following July. The Annual Enrollment Period for Medicare Advantage and Part D runs October 15 through December 7, with changes taking effect January 1.15Centers for Medicare & Medicaid Services. Medicare Open Enrollment
Certain events trigger Special Enrollment Periods that let you enroll outside those windows, such as losing employer coverage, moving to a new area, or being released from incarceration.8Medicare.gov. Understanding Medicare Advantage and Medicare Drug Plan Enrollment Periods Any gap can still trigger the late enrollment penalties, and those stick with you permanently.
How to Keep Your Coverage From Ending
Set Up Automatic Payments
The single best way to prevent accidental disenrollment is to stop relying on paper bills. Medicare Easy Pay allows free automatic deductions from your checking or savings account for Part A and Part B premiums, and the payment amount updates when premiums change. You can sign up through your Medicare account online or by mailing form SF5510. Automatic deductions take six to eight weeks to begin, so keep paying manually in the meantime.16Medicare.gov. Medicare Easy Pay For Medicare Advantage and Part D plans, contact the plan directly about autopay.
Keep Your Address Current With Social Security
Social Security maintains Medicare enrollment records. A wrong address means premium bills and coverage notices go somewhere you can’t see them, and you learn about a problem only after coverage has ended. Update your address through your my Social Security account online, by phone, or at a local office. Notify any Medicare Advantage or Part D plan separately, since plans keep their own records.
Read the Annual Notice of Change
Most Medicare plans renew automatically, but benefits, costs, and provider networks can shift year to year. The Annual Notice of Change that your plan sends each fall shows premium increases and dropped providers before they hit you mid-year. If the changes don’t work for you, the Annual Enrollment Period from October 15 through December 7 is when you can switch plans, move between Medicare Advantage and Original Medicare, or change your Part D coverage.15Centers for Medicare & Medicaid Services. Medicare Open Enrollment