A Special Enrollment Period (SEP) is a time-limited window outside the standard enrollment periods that allows you to sign up for or change Medicare coverage because of a specific qualifying life event. These windows are fixed — typically 60 days for plan changes, 8 months for the employer-coverage Part B SEP — and once they close, you may face a coverage gap or a wait until the next Annual Enrollment Period.
This page covers the most common SEP triggers, how long each window lasts, and what to do before yours closes.
What Triggers a Special Enrollment Period
Each of the following qualifying events opens a limited window to make changes to your Medicare coverage. Find your situation and act within the timeframe listed.
- Loss of employer or group health coverage — The most common SEP trigger. If you lose coverage through your own employment or a spouse’s employment — due to retirement, job loss, or the employer ending the plan — you have an 8-month SEP to enroll in Medicare Part B. The 8 months begin from the later of the date employment ends or the date coverage ends. Enroll as soon as coverage ends to avoid a gap. COBRA does not extend this window. For the full rules on employer coverage and Medicare, see our Still Working at 65 guide.
- Moving out of your plan’s service area — If you have a Medicare Advantage or Part D plan and move to an area the plan does not serve, you get a 60-day SEP starting from the date of the move to switch to a plan that covers your new location.
- Your plan leaves Medicare or ends coverage in your area — If your Medicare Advantage or Part D plan stops operating, loses its Medicare contract, or stops serving your county, you get a 60-day SEP to enroll in a new plan. Plans are required to notify members in advance when this happens.
- Gaining or losing Medicaid or Extra Help (Low Income Subsidy) — Becoming newly eligible for Medicaid or the Part D Extra Help program triggers a SEP to add or change coverage. Losing Medicaid eligibility also triggers a SEP. Window is 60 days from the change in eligibility.
- Moving into or out of a care facility — Moving into a skilled nursing facility, nursing home, or other qualifying care facility triggers a SEP. Moving out also triggers a SEP. Window is 60 days before or after the move.
- Plan significantly changes its benefits or costs — If your Medicare Advantage or Part D plan makes a significant mid-year change to benefits, formulary, or provider network that affects you, a SEP may be triggered. Check your plan’s Annual Notice of Change for details.
- Returning from abroad or release from incarceration — Returning to the US after living abroad, or being released from incarceration, each trigger a 60-day SEP to enroll in Medicare.
What You Can Do During a SEP
During a Special Enrollment Period, depending on the trigger, you may be able to:
- Enroll in Medicare Part B (if you delayed it due to employer coverage)
- Join a Medicare Advantage plan
- Switch Medicare Advantage plans
- Join, switch, or drop a Part D drug plan
- Return to Original Medicare from a Medicare Advantage plan
What you can change depends on which SEP was triggered. Not all SEPs allow all changes — the event type determines the options available.
The Urgency of Acting Now
SEP windows are fixed and do not extend once they begin. Missing a SEP typically means waiting until the next Annual Enrollment Period (October 15 – December 7, with coverage starting January 1) — which could mean months without the right coverage or exposure to costs your old plan would have covered.
If you have a qualifying event and are unsure whether it triggers a SEP or what your window is, confirm before the window closes — not after.
Missing your window can mean months without the right coverage or a permanent gap in your Medicare record.
⚠️ Medicare enrollment has deadlines — missing them costs you money.
Late enrollment penalties for Medicare Part B and Part D can follow you for life. If you’re approaching 65 or a qualifying life event, don’t wait. Our partner Chapter Medicare offers free, expert guidance on enrollment timing and plan selection.
📞 Call 615-639-1937 | 🔗 askchapter.org/money
Help is ALWAYS FREE. Chapter is compensated by insurance carriers, not by you.
How to Act During a SEP
- Identify your qualifying event and confirm the SEP type and window length using this page or by calling 1-800-MEDICARE.
- Do not wait until the end of the window — enroll or make changes as soon as possible to avoid any gap between old and new coverage.
- For Part B enrollment during an employer-coverage SEP: contact Social Security directly at 1-800-772-1213 or apply at ssa.gov.
- For Medicare Advantage or Part D plan changes: use medicare.gov/plan-compare to identify available plans, or call a licensed Medicare advisor for a free comparison.
- Keep documentation of the qualifying event — proof of loss of coverage, move date, or plan termination notice — in case it is needed for enrollment verification.
🆓 Don’t navigate enrollment alone — free help is available.
Our partner Chapter Medicare can help you confirm your enrollment window, avoid penalties, and choose the right plan before your deadline.
📞 Call 615-639-1937 | 🔗 askchapter.org/money
ALWAYS FREE. No obligation.
Disclosure: We may receive a referral from Chapter if you choose to use their service. Chapter is a licensed health insurance agency and is not affiliated with or endorsed by Medicare or any government agency.
Related Medicare guides
Medicare Enrollment Deadlines & Penalties — Every enrollment window, the late penalties, and how to avoid them
Still Working at 65: Medicare and Employer Coverage — Full rules for the employer-coverage SEP, COBRA, HSA contributions, and the 8-month window
Turning 65? Your Medicare Guide — What Medicare is, when to enroll, and what it will cost you
Free Medicare Help from Chapter Medicare — What Chapter is, who they help, and what to expect before you call
Medicare Overview — How Medicare is structured, what each part covers, and how to navigate the system