Guide
Medicare enrollment deadlines for 2026–2027
By the CareQualityScore editorial team · How we write our guides
Medicare has several enrollment windows, and missing one can mean waiting months or paying a penalty for life. Here they are.
Open Enrollment: October 15 to December 7
This is the big one. Anyone on Medicare can:
- switch from Original Medicare to a Medicare Advantage plan, or back
- switch from one Medicare Advantage plan to another
- join, switch or drop a Part D drug plan
Changes take effect January 1. Plans change their premiums, benefits and networks every year, so even if you're happy, read the "Annual Notice of Change" your plan sends in the fall.
Medicare Advantage Open Enrollment: January 1 to March 31
If you're already in a Medicare Advantage plan, you get one change during this window. You can switch to a different Medicare Advantage plan, or drop back to Original Medicare and join a Part D plan. People on Original Medicare can't use this window to join Medicare Advantage.
Your Initial Enrollment Period
When you first become eligible at 65, you have seven months to sign up: the three months before your birthday month, the month itself, and the three months after. Signing up before your birthday month means coverage starts on time.
General Enrollment: January 1 to March 31
If you missed your Initial Enrollment Period and don't qualify for a Special Enrollment Period, you can sign up for Part A and/or Part B here. Coverage starts the month after you sign up, and late enrollment penalties may apply.
Special Enrollment Periods
Certain life events open a window outside the usual dates. For example: you move, you lose employer coverage, you move into or out of a nursing home, or you qualify for Extra Help or Medicaid. There's also a Special Enrollment Period to switch into a 5-star plan once a year, if one is available where you live.
About penalties
If you don't sign up for Part B or Part D when you're first eligible, and you don't have other qualifying coverage (like a large employer plan), you can owe a late enrollment penalty added to your premium for as long as you have that coverage. If you're still working at 65, check with your employer's benefits office before deciding to delay.
Free, unbiased help is available from your State Health Insurance Assistance Program (SHIP).
Compare
Sources
- Medicare: Joining a plan / When can I join a health or drug plan?
- Medicare: When does Medicare coverage start?
- Social Security Administration: Medicare enrollment
This guide is general information, not medical, legal or financial advice. Rules change, so check the details with the official source or a qualified professional.