At a glance
Start with these three things.
Starting Medicare
Your first enrollment window depends on your circumstances.
Reviewing a plan
Annual and special windows allow particular changes.
Adding a Supplement
Medigap has its own enrollment protections.
Find your window
Five windows. Different purposes.
First enrollment
7 months
Around your 65th birthday, for many people.
Annual enrollment
Oct 15 – Dec 7
Review Medicare Advantage and Part D plans.
Advantage open enrollment
Jan 1 – Mar 31
Certain changes for people already in Medicare Advantage.
Special enrollment
Life changes
A qualifying event may create another opportunity.
Medigap open enrollment
6 months
Generally from age 65 or older when Part B begins.
Your questions, unpacked
Enrollment periods: your questions, answered.
Starting Medicare for the first time
For many people turning 65, the Initial Enrollment Period spans seven months around their birthday month. The date you enroll can affect when coverage starts.
People who delay because of qualifying current employment coverage may have a different enrollment opportunity. Check before delaying or ending coverage.
Reviewing Medicare plans
Medicare Advantage and prescription drug plans have their own enrollment periods. Special Enrollment Periods can also apply after certain changes in your circumstances.
Use the official Medicare plan enrollment guide to confirm the dates, eligibility, and changes permitted. Do not assume every enrollment window allows every change.
Considering a Medicare Supplement
Your Medigap Open Enrollment Period generally begins when you are at least 65 and your Part B coverage starts, and lasts six months. State protections and other rights can affect your options.
This is a separate decision from Medicare’s annual plan enrollment. Ask about acceptance rules before moving between coverage routes.
Sources & further reading
Related guidance