First Time on Medicare: New Beneficiary Guide
Your 65th birthday is a deadline, not just a milestone. Three months before, start learning Medicare, enroll in Part B and D, and choose a plan. Late moves cost you.
Medicare AEP Deadlines and Coverage Dates
AEP runs October 15 to December 7. If you enroll during this window, coverage starts January 1. Miss it, and you wait a year unless you have a qualifying event.
AEP dates and coverage start
The Annual Enrollment Period (AEP) runs October 15 through December 7 each year. Any plan changes you make during this window take effect January 1 of the following year.
Enroll, switch plans, or drop coverage anytime during these dates — the January 1 effective date applies to all changes made during AEP.
Why the December 7 deadline matters
Applications must be submitted by 11:59 p.m. ET on December 7 to be processed for the January 1 effective date. After December 7, you generally cannot make changes until next AEP unless you have a qualifying life event.
A qualifying life event (loss of coverage, move, death in family, marriage) can create a Special Enrollment Period. Outside of AEP or a SEP, you are locked into your current plan for the entire year.
What to do if you miss AEP
If you miss the December 7 deadline, check whether you qualify for a Special Enrollment Period due to a life change. If not, your next opportunity to change plans is the following October 15.
You remain in your current plan for the remainder of the year, so it's critical to make intentional changes during AEP rather than waiting.
Get started early, not on December 6
AEP is nearly 8 weeks long — use that time to compare plans, review your prescriptions against drug formularies, check provider networks, and make an informed decision.
Waiting until the last week creates unnecessary stress and leaves no time to ask questions or verify your choices.
Frequently asked questions
When does my new Medicare plan coverage start?
January 1 of the year following your AEP enrollment. This applies to all changes made during the AEP window, regardless of when you enroll.
Can I enroll anytime I want?
Only during AEP (October 15 – December 7) or if you have a qualifying life event that triggers a Special Enrollment Period. Outside these windows, you cannot change plans.
What counts as a qualifying life event?
Loss of health coverage, moving to a new state or county, death in the family, marriage, or other approved changes. Confirm with Medicare whether your event qualifies.
What if I miss the December 7 deadline?
Your next chance to change plans is the following October 15, unless you qualify for a Special Enrollment Period due to a life change.
General educational information only, not medical, legal, or tax advice. AEP dates, qualifying life events, and effective dates are set by CMS and can change. Confirm current dates and deadlines directly with Medicare or at Medicare.gov.
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