Every Medicare Enrollment Period — Explained
Miss the wrong window and you could face permanent penalties or a gap in coverage. Here's exactly when you can enroll, switch, or drop your Medicare plan.
Why Enrollment Periods Matter
Medicare doesn't let you enroll or change plans whenever you want. The federal government sets specific windows — and missing them can mean permanent premium penalties, gaps in coverage, or being locked into a plan that doesn't fit your needs for an entire year. Understanding which window applies to your situation is the first step to making a smart Medicare decision.
Not sure which enrollment period applies to you? Call 386-871-3858 for a free, no-obligation review.
Medicare Enrollment Periods at a Glance
Initial Enrollment Period (IEP)
7 months around your 65th birthdayWho: People turning 65 or newly eligible for Medicare
What you can do: Enroll in Medicare Part A, Part B, Part D, and/or a Medicare Advantage plan
⚠ Missing this window without creditable coverage triggers permanent Part B and Part D late enrollment penalties
Annual Enrollment Period (AEP)
October 15 – December 7 each yearWho: All Medicare beneficiaries
What you can do: Switch Medicare Advantage plans, switch Part D plans, move from Advantage back to Original Medicare, or enroll in Part D for the first time
Medicare Advantage Open Enrollment Period (OEP)
January 1 – March 31 each yearWho: People currently enrolled in a Medicare Advantage plan
What you can do: Switch to a different Medicare Advantage plan or return to Original Medicare (with or without a Part D plan)
Special Enrollment Period (SEP)
Varies — typically 2 months from qualifying eventWho: People who experience a qualifying life event
What you can do: Enroll in, switch, or drop Medicare coverage outside of standard windows
General Enrollment Period (GEP)
January 1 – March 31 each yearWho: People who missed their IEP and don't qualify for an SEP
What you can do: Enroll in Part A and/or Part B; coverage begins July 1
⚠ Late enrollment penalties apply if you missed your IEP without creditable coverage
Medigap Open Enrollment Period
6 months starting when you first enroll in Part B at 65+Who: People newly enrolled in Medicare Part B at age 65 or older
What you can do: Buy any Medicare Supplement (Medigap) plan without medical underwriting — guaranteed issue
⚠ After this window closes, insurers can deny coverage or charge higher premiums based on health history
Common Special Enrollment Period Triggers
A Special Enrollment Period (SEP) lets you make Medicare changes outside the standard windows when a qualifying life event occurs.
Plan leaves your service area or stops offering coverage
2 months from notice
Qualifying for Extra Help (Low Income Subsidy)
Anytime while eligible
Moving into or out of a nursing facility
2 months from move
The Medicare Calendar Year
General Enrollment Period + MA Open Enrollment Period
No standard enrollment windows (SEPs may apply)
Annual Enrollment Period — most changes happen here
AEP closed; plan changes take effect Jan 1
Enrollment Periods FAQ
Not Sure Which Enrollment Window Applies to You?
Every situation is different. I'll review your specific circumstances and make sure you don't miss a critical enrollment window — or pay a penalty you didn't have to.