Initial Enrollment Period for Part D
Your first opportunity to join a Medicare drug plan generally begins 3 months before you first get Medicare Part A or Part B and ends 3 months afterward. You need either Part A or Part B to join a standalone Part D plan. People who qualify for Medicare before age 65 generally receive another Part D Initial Enrollment Period when they turn 65.
If the plan receives your request before Medicare Part A or Part B starts, drug coverage generally begins on the same date. If the request arrives after Medicare coverage starts, Part D generally begins the first day of the following month.
Annual Enrollment Period (AEP)
The main window to make changes to your Part D coverage each year. Runs October 15 – December 7. During AEP you can:
- Enroll in a Part D plan for the first time if you missed your initial period
- Switch from one Part D plan to another
- Drop a Part D plan (not recommended unless you have other creditable coverage)
- Switch from Original Medicare + Part D to Medicare Advantage with drug coverage
Medicare Advantage Open Enrollment Period (OEP)
January 1 – March 31 each year. If you're enrolled in a Medicare Advantage plan, you can switch to a different MA plan or drop MA and return to Original Medicare (and enroll in a standalone Part D plan). This period does not allow you to enroll in a Part D plan if you're already on Original Medicare without drug coverage.
Special Enrollment Periods (SEPs)
Certain life events trigger a Special Enrollment Period that allows you to make Part D changes outside the standard windows. The deadline depends on the event, so confirm the specific start and end dates that apply to you:
- Moving out of your plan's service area
- Losing other creditable drug coverage (employer plan, TRICARE, VA)
- Qualifying for Extra Help (Low Income Subsidy)
- Moving into or out of a long-term care facility
- Your plan loses its contract with Medicare
- Gaining or losing Medicaid eligibility