If you’re enrolling in Medicare for the first time, there’s a fairly straightforward process – and timeline. (Here’s what you need to know about enrolling for the first time, the steps you need to take, and what to expect in terms of costs.)
But beyond that first opportunity to enroll in Medicare plans, the federal government provides other windows for enrollment: annual opportunities to enroll if you’ve delayed your enrollment for some reason or to change your coverage if you’ve already enrolled.
Here’s a quick guide to the times when you can enroll in – or change – Medicare coverage during the year.
2026 Medicare open enrollment period / annual election period (Medicare Advantage & Part D)
Dates: October 15, 2025 – December 7, 2025 – Changes effective January 2026
Enrollment / plan change options:
Learn more about the Medicare open enrollment period. The open enrollment (annual election) period is a well-promoted annual opportunity to enroll or make a plan change. But as described below, there are also other opportunities to enroll or make coverage changes during the year.
5-star enrollment period (Special enrollment for 5-star plans)
Dates: December 8, 2024 – November 30, 2025 for coverage effective in 2025. The dates are the same each year, so for coverage effective in 2026, this window runs from December 8, 2025 – November 30, 2026. Coverage in the new plan takes effect the month after you submit your enrollment.
Enrollment / plan change options:
During this annual special enrollment period, you can join or switch to a 5-star Medicare Advantage plan or Part D drug plan if you live in an area where a 5-star plan is available. (See the list of plans that have five stars for 2025; the star ratings for 2026 will be published by CMS in October 2025) But you can only use this enrollment opportunity once in each December 8 to November 30 window.
Learn more about the 5-star enrollment period.
Medicare Advantage Open Enrollment Period (MAOEP)
Only applies to people who already have Medicare Advantage plans.
Dates: January 1 – March 31, 2026 – Your plan change takes effect the month after you submit your enrollment.
Enrollment / plan change options:
- Switch from Medicare Advantage to Original Medicare plus a Part D plan
- Switch from one Medicare Advantage plan to another
- You can only make one change during this open enrollment period (as opposed to the fall enrollment period when you can change your mind multiple times if necessary).
Learn more about Medicare Advantage open enrollment.
General enrollment period (Part A and Part B)
Dates: January 1 – March 31, 2026 – Coverage takes effect the first of the month following enrollment. (Before 2023, coverage would take effect July 1, but that’s no longer the case.)
Enrollment / plan change options:
- General enrollment for Part B – for people who didn’t sign up when they were first eligible. A late enrollment penalty may apply.
- Part A general enrollment period – for people who have to pay premiums for Medicare Part A and didn’t sign up when first eligible (Late enrollment penalty may apply.)
- Note that the GEP is not an opportunity to change from one plan to another. It simply allows people to sign up for Medicare Part B (and Part A, if they have to pay a premium) if they didn’t enroll when they were initially eligible and haven’t qualified for a special enrollment period.
- Beneficiaries who enroll in Medicare Parts A and B during the general enrollment period can also enroll in a Part D plan to supplement their coverage, OR enroll in a Medicare Advantage plan. Access to Medigap plans will vary depending on state laws. (Click on a state on this map to see how Medigap plans are regulated.)
Learn more about Medicare Part A.
Learn more about Medicare Part B.
Louise Norris is an individual health insurance broker who has been writing about health insurance and health reform since 2006. She has written hundreds of opinions and educational pieces about the Affordable Care Act and Medicare for healthinsurance.org and medicareresources.org.
