The short answer
When can I enroll in or change Medicare coverage?
Medicare enrollment timing depends on your eligibility, current coverage, and the change you want to make. Common windows include the Initial Enrollment Period around first eligibility, Annual Enrollment from October 15 through December 7, Medicare Advantage Open Enrollment from January 1 through March 31, and event-specific Special Enrollment Periods.
Initial Enrollment Period
For many people, the Initial Enrollment Period is a seven-month window that begins three months before the month they turn 65, includes their birthday month, and ends three months afterward. Different timing can apply if Medicare eligibility is based on disability or another circumstance.
Annual Enrollment Period
From October 15 through December 7, people with Medicare can generally review and change Medicare Advantage or Part D coverage for the next calendar year. This is a useful time to recheck medications, providers, benefits, and costs.
Medicare Advantage Open Enrollment Period
From January 1 through March 31, people already enrolled in Medicare Advantage can generally switch to another Medicare Advantage plan or return to Original Medicare and join a standalone Part D plan. This period does not allow every type of change.
Special Enrollment Periods
Certain events may create a Special Enrollment Period, such as losing qualifying employer coverage, moving outside a plan's service area, or qualifying for certain assistance programs. The allowed change and deadline depend on the event.
- Do not assume a life event automatically qualifies.
- Keep notices that show when coverage ended or your circumstances changed.
- Confirm exact timing with Medicare.gov, Social Security, or a licensed insurance agent.
Official sources
This article is educational and is not a final plan recommendation. Verify current plan details, costs, formularies, networks, eligibility and enrollment timing with a licensed insurance advisor before making a decision.