Initial Enrollment Period (IEP)
A 7-month window around your 65th birthday: the 3 months before your birthday month, your birthday month, and the 3 months after.
Annual Enrollment Period (AEP) — October 15 to December 7
Each year you can join, switch, or drop a Medicare Advantage or Part D plan. Changes start January 1.
Medicare Advantage Open Enrollment Period (OEP) — January 1 to March 31
If you are already in a Medicare Advantage plan, you can make one change: switch to a different Medicare Advantage plan, or go back to Original Medicare (and join a Part D plan).
Special Enrollment Periods (SEPs)
Certain life events let you make changes outside the usual windows. Examples:
- Moving out of your plan’s service area.
- Losing employer or other creditable coverage.
- Qualifying for Medicaid or Extra Help.
- Moving into or out of a nursing home.
Medicare Supplement Open Enrollment
A one-time 6-month window that starts the month you are 65 or older and enrolled in Part B. During this time, you can generally buy any Supplement plan sold in your state without health questions.
This guide is general education, not advice about a specific plan. Rules and amounts can change each year.
← All Medicare guides