Timing
The dates that matter, without the panic.
Which window applies to you depends on your birthday and your current coverage.
Turning 657 months
Your personal windowInitial Enrollment Period
7 months: it starts 3 months before the month you turn 65 and ends 3 months after it.
Every yearOct 15 – Dec 7
Solid brass on the year viewAnnual Enrollment runs October 15 to December 7.
That is close to eight weeks. You do not need to decide in the first few days. Any change takes effect January 1.
Anyone telling you otherwise is creating urgency that isn't there.
Already on Medicare AdvantageJan 1 – Mar 31
Solid ink on the year viewJanuary 1 to March 31.
This window is only for people already enrolled in a Medicare Advantage plan. You can switch to another Medicare Advantage plan, or drop your plan and return to Original Medicare, and join a separate drug plan if you do.
You can only make one change during this period. The change starts the first of the month after the plan gets your request. If you're new to Medicare and enrolled in a Medicare Advantage plan, you also have this opportunity during the first three months you have Medicare.
Life eventsVaries
Dashed on the year viewSome life events open a Special Enrollment Period.
Moving, losing or changing your current coverage, getting Medicaid, or getting Extra Help with drug costs can each let you join or switch plans outside these dates. The timing depends on your situation.
Working past 65?
8 months after job coverage ends.
If you're covered through a current job, you can generally sign up for Part B later: any time you're still covered, or within 8 months after the job or the coverage ends, whichever happens first.
Every autumn
Two checks worth doing.
1Read your Annual Notice of Change.
Your plan can change its costs, its network and its drug list every year. A short review each autumn is how people avoid ending up on the wrong plan by default.
2Check your doctors and prescriptions first.
A plan that looks good on paper is the wrong plan if it doesn't cover your medication or your specialist. That check comes before comparing prices.
Medicare.gov lists every enrollment period and who qualifies: Medicare.gov: Joining a plan.
Next
Find out which window is yours.
Sources: Medicare.gov: When does Medicare coverage start? · Medicare.gov: Joining a plan · Medicare & You 2027 (official handbook) pp.17-18, 75. Rules can change; Medicare.gov has the latest.
Want help with the next step?
A Licensed Insurance Agent can walk you through your options, or you can start comparing plans on your own. There is no obligation to enroll.