No, you do not have to re-enroll for Medicare every year. Once you’re signed up for Part A, Part B, a Medicare Advantage plan, or a Part D drug plan, your coverage rolls over from one year to the next on its own. There’s no annual form, no renewal deadline, and no risk of your coverage lapsing because you forgot to file something. What the calendar does give you each fall is a chance to switch plans if you want to, not a requirement to reapply for the ones you already have.
What Renews Automatically
Original Medicare, meaning Part A and Part B, is continuous coverage. It stays active as long as you remain eligible and keep paying any required premiums.1Centers for Medicare & Medicaid Services. Original Medicare (Part A and B) Eligibility and Enrollment Eligibility here means you’re a U.S. citizen, or a lawful resident who has lived in the country for at least five continuous years. Nothing about that has to be re-proven annually.
Medicare Advantage (Part C) plans and Part D prescription drug plans work the same way from the beneficiary’s side. If you do nothing, your plan continues into the new year. The one thing you should watch for is the paperwork your plan is required to send. By September 30 each year, your Medicare Advantage or Part D plan must mail you an Annual Notice of Change spelling out any adjustments to premiums, copays, covered drugs, or provider networks for the coming year. Read it. If everything still works for you, no action is needed.
The one situation where a plan won’t roll over is if the insurer decides to discontinue it. In that case, the plan must notify you at least 60 days before the contract period ends, and you’ll get a Special Enrollment Period to choose new coverage.2eCFR. 42 CFR 417.492 – Nonrenewal of Contract
The Fall Window if You Want to Change Plans
Medicare’s annual Open Enrollment Period runs from October 15 through December 7, and any changes you make take effect January 1.3Medicare. Open Enrollment This is an opportunity, not an obligation. During this window you can:
- Switch from Original Medicare to a Medicare Advantage plan, or from Medicare Advantage back to Original Medicare.
- Change from one Medicare Advantage plan to another, including plans that add or drop drug coverage.
- Join a Part D prescription drug plan, drop your current one, or switch to a different one if you have Original Medicare.
Formularies change. Provider networks shrink. Premiums shift. The Annual Notice of Change is meant to flag those adjustments so you can compare before the window closes. If nothing in the notice matters to you, sitting tight is fine and your plan simply continues.
A Second, Narrower Window for Medicare Advantage Members
People already enrolled in a Medicare Advantage plan get one additional window each year. The Medicare Advantage Open Enrollment Period runs from January 1 through March 31, and it lets you make a single change: switch to a different Medicare Advantage plan, or drop Medicare Advantage entirely and return to Original Medicare (picking up a Part D plan at the same time if you want drug coverage).4Medicare. Understanding Medicare Advantage and Medicare Drug Plan Enrollment Periods Changes take effect the first day of the month after your plan receives the request.
This period doesn’t let someone in Original Medicare move into Medicare Advantage, and it doesn’t let Original Medicare beneficiaries change Part D plans. It exists mainly as a safety valve for people who chose a Medicare Advantage plan during the fall and realized after January 1 that it wasn’t the right fit.
When You Actually Do Need to Take Action
Automatic renewal handles the enrollment side, but keeping your coverage active still involves a few responsibilities.
Pay Your Premiums
The standard Part B premium in 2026 is $202.90 per month, and for most people it’s deducted automatically from Social Security benefits. If you don’t collect Social Security, Medicare bills you directly. Unpaid premiums can result in termination of coverage, and getting reinstated means waiting for the next enrollment period and potentially facing late enrollment penalties. If you ever receive a bill marked “Delinquent,” pay the full amount promptly.5Medicare. How to Pay Part A and Part B Premiums
Keep Your Contact Information Current
Update Social Security if you move or change phone numbers so bills, notices, plan mailings, and your Medicare card reach you.6Social Security Administration. Update Contact Information Missed notices can turn into missed deadlines.
Act on Life Changes That Open Special Enrollment Periods
Certain events give you a limited window to make plan changes outside the regular calendar, including moving out of your plan’s service area, losing employer or union coverage, losing COBRA, qualifying for Extra Help with drug costs, or having your plan discontinued.7Medicare. Special Enrollment Periods The timing depends on the event. After losing employer or COBRA coverage, for example, you have two full months after the month coverage ends to join a Medicare Advantage or Part D plan.
If you delayed Part B while working past 65 with employer coverage, the end of that job or that group health plan triggers an eight-month Special Enrollment Period to sign up for Part B without penalty.8Medicare. Working Past 65 One trap worth flagging: COBRA does not count the same way as active employer coverage. Your eight-month clock starts when the employment ends, not when COBRA runs out.
Medigap Is the Exception You Can’t Fix Later
One thing that does not renew or reopen is your Medigap Open Enrollment Period. If you have Original Medicare and want a Medicare Supplement (Medigap) policy to cover deductibles, copays, and coinsurance, you get one six-month window that starts the first month you have Part B and are 65 or older.9Medicare. Your Medigap Open Enrollment Period During those six months, no insurer can refuse you, charge you more for pre-existing conditions, or deny coverage based on your health history.
Once that window closes, insurers in most states can use medical underwriting, meaning they can reject your application or charge higher premiums based on your health.10Medicare. When Can I Buy a Medigap Policy The fall Open Enrollment Period does not reopen Medigap access. Some states offer additional protections beyond federal rules, so if you’re past the deadline it’s worth checking with your state insurance department before assuming you’re locked out.
The Short Version
Your Medicare coverage renews itself. Read the Annual Notice of Change when it arrives in September, decide whether to shop around during Open Enrollment in the fall, pay your premiums, and tell Social Security when your address changes. That’s the whole annual routine.