Medicare Special Enrollment Periods: When You Can Sign Up Outside Open Enrollment

SEP for Losing Employer Coverage

The most common SEP: if you delayed Medicare enrollment because you had active employer or union health coverage (your own or a spouse's), you can sign up for Parts A and B during an 8-month window that starts when the employment ends or the coverage ends — whichever comes first.

Critical clarification: COBRA does NOT extend your SEP. If you lose employer coverage and elect COBRA, your 8-month SEP clock has already started. Waiting to exhaust COBRA before enrolling in Medicare can leave you without a valid SEP — and subject to permanent late enrollment penalties.

Act promptly when your employer coverage ends. Eight months sounds generous, but Medicare enrollment, plan selection, and Medigap applications all take time. Starting within the first 2–3 months gives you the most flexibility.

SEP for Medicare Advantage and Part D Plan Changes

Once you're enrolled in Medicare, there are additional SEPs that let you change your Advantage or Part D plan mid-year if specific circumstances arise:

• Moving out of your plan's service area to a new county or state
• Your plan leaving your service area or stopping coverage
• Qualifying for Medicaid (dual eligible) or Extra Help with drug costs
• Moving into, or out of, a nursing home or long-term care facility
• Losing other creditable prescription drug coverage
• Plan fraud or material misrepresentation by the plan

The Five-Star SEP

A lesser-known SEP: if a Medicare Advantage or Part D plan in your area earns a 5-star quality rating from Medicare, you can switch to that plan once per calendar year using the Five-Star SEP. This SEP runs year-round (except November and December) and can be used even outside the Annual Election Period.

In practice, 5-star plans are rare — Medicare gives the rating to fewer than 5% of plans in any given year. But when one exists in your area, the Five-Star SEP gives you access to the highest-rated coverage available without waiting for AEP.

What to Do When You Have a Qualifying Event

Act quickly — most SEPs have strict deadlines. The 8-month Part B SEP doesn't restart; if you miss it, you'll wait until the next General Enrollment Period (January 1 – March 31) with potential gaps in coverage.

Gather documentation of the qualifying event: a letter from your employer confirming coverage end date, a notice from your plan, or other relevant paperwork. Have it ready when you contact Social Security (for Parts A and B) or your carrier/Medicare.gov (for Parts C and D).

If you're unsure whether your situation qualifies for a SEP, contact us before making any plan changes. Getting the sequence wrong — or missing a deadline — can have lasting financial consequences.