Understanding Medicare Enrollment Periods

Knowing when you can enroll in or change your Medicare coverage is crucial. Missing these windows can result in penalties or gaps in coverage.

Initial Enrollment Period (IEP)
First-time enrollment

Your 7-month window to first sign up for Medicare:

  • 3 months before your 65th birthday month
  • Your 65th birthday month
  • 3 months after your 65th birthday month

Important:

Delaying enrollment past your IEP may result in permanent late enrollment penalties that increase your premiums for life.

Annual Enrollment Period (AEP)
Oct 15 - Dec 7

The main opportunity each year to make changes to your Medicare coverage:

  • Join, switch, or drop a Medicare Advantage plan
  • Join, switch, or drop a Part D prescription drug plan
  • Switch from Original Medicare to Medicare Advantage (or vice versa)

Coverage begins: Changes made during AEP take effect January 1st

Medicare Advantage Open Enrollment
Jan 1 - Mar 31

If you're in a Medicare Advantage plan, you can:

  • Switch to a different Medicare Advantage plan
  • Return to Original Medicare (and join a Part D plan)

Note: You can only use this period once per year

Special Enrollment Periods (SEP)
Life events

You may qualify to make changes outside regular enrollment periods due to:

Common qualifying events:

  • • Moving out of your plan's service area
  • • Losing employer or union coverage
  • • Qualifying for Medicaid or Extra Help
  • • Living in a nursing home
  • • Your plan exits Medicare or your area

SEP timelines vary based on the qualifying event. Some last 2 months, others continue as long as you qualify.

Quick Reference Calendar

January - March

Medicare Advantage Open Enrollment

October 15 - December 7

Annual Enrollment Period

Year-round

Special Enrollment Periods (if you qualify) and Initial Enrollment (7 months around 65th birthday)