Enrollment
Special Enrollment Period (SEP)
Quick answer
A Special Enrollment Period (SEP) is a window outside the standard windows when you can join, switch, or drop a plan. SEPs are triggered by qualifying life events like moving, losing employer coverage, or becoming eligible for Medicaid.
Plain-English definition
Each SEP has its own eligibility rules and time limits — usually two months from the event.
Why it matters
Missing a SEP can lock you out of changes for months and cause coverage gaps.
A simple example
You move from Ohio to Arizona. That triggers a SEP to choose a new plan in your new ZIP.
Common mistakes & misconceptions
Related terms
Annual Election Period (AEP)
The Annual Election Period (AEP) runs October 15 – December 7 each year. During AEP anyone with Medicare can join, switch, or drop a Medicare Advantage or Part D plan. Changes take effect January 1.
SEP for Moving
Moving out of your plan's service area triggers a Special Enrollment Period to switch to a plan in your new location, usually for up to 2 months after your move.
SEP for Losing Employer Coverage
Losing employer or union group health coverage triggers a Special Enrollment Period to enroll in Part B and to join Part D or a Medicare Advantage plan — typically 8 months for Part B and 63 days for Part D.
SEP for Medicaid Change
Gaining, losing, or having a change in Medicaid status triggers a Special Enrollment Period to switch Medicare Advantage or Part D plans, so your coverage matches your new dual-eligible status.
Frequently asked questions
How long does a SEP last?+
Usually 2 months from the qualifying event.
Sources & references
📚 Where this information comes from
- Medicare.gov — official U.S. government site for people with Medicare ↗Primary source for benefits, enrollment periods, and plan comparison.
- CMS.gov — Centers for Medicare & Medicaid Services ↗Federal rulemaking, program updates, and official guidance.
- Social Security Administration — Medicare enrollment & premiums ↗Enrollment, premium withholding, and IRMAA determinations.
When you're ready, compare plans on your own terms
See Medicare Advantage plans from the insurance companies we represent, or walk the course with a licensed agent whenever you'd like a second set of eyes.
We help compare Medicare Advantage plans from the insurance companies we represent, and we don't offer every plan available in your area.
Medicare Caddies is an independent insurance agency. We are not affiliated with, endorsed by, or connected to the U.S. government, the federal Medicare program, or the Centers for Medicare & Medicaid Services (CMS). We help compare Medicare Advantage plans from the insurance companies we represent, and we don't offer every plan available in your area.