Enrollment
When Can You Switch Medicare Plans? All Enrollment Periods
Not sure when you can change your Medicare plan? This guide covers all enrollment windows — AEP, MAOEP, IEP, SEP — and exactly what you can change in each.
Quick Summary
You can't change Medicare plans whenever you want. Most changes happen during the fall Annual Enrollment, but you might also qualify for a 'Special Enrollment Period' if you move or lose your job coverage.
One of the most common questions from seniors is: 'when can you switch medicare plans?' Medicare uses specific enrollment windows throughout the year to manage when people can join or leave plans. Understanding these dates is the only way to avoid being 'locked in' to a plan you don't like. Here is the 2026 calendar.
The Master Enrollment Calendar
| Enrollment Period | Dates | Eligible Changes | Who Qualifies |
|---|---|---|---|
| Initial (IEP) | 7 months around 65th birthday | Sign up for any part of Medicare | Newly eligible for Medicare |
| Annual (AEP) | Oct 15 - Dec 7 | Switch between Original and MA; change Part D | All Medicare beneficiaries |
| MA Open (OEP) | Jan 1 - Mar 31 | Switch MA plans; go back to Original | Current MA plan members only |
| Special (SEP) | Varies (usually 60 days) | Varies by the life event | Those who move or lose job coverage |
Special Enrollment Periods (SEPs)
An SEP allows you to make changes outside of the regular fall window. These are triggered by 'qualifying life events.' Common examples include:
- Moving to a new ZIP code that isn't in your current plan's service area
- Losing 'creditable' health coverage from an employer or union
- Moving into or out of a nursing home or long-term care facility
- Qualifying for 'Extra Help' or Medicaid
- Your current plan loses its contract with Medicare or is terminated
5-Star Plan SEP
If a 5-star rated Medicare Advantage plan is available in your area, you have a one-time SEP to switch to it at any time during the year (between Jan 1 and Nov 30).
What You Can Change in Each Window
During AEP (Fall), you have total freedom. You can move from Original Medicare to Advantage, or vice-versa. During the MA OEP (Winter), you can only switch if you are ALREADY in an Advantage plan.
Medigap Windows are Different
Medigap (Supplement) plans have their own rules. You have a 6-month 'Medigap Open Enrollment' starting when you have Part B at age 65. Outside of that, you usually have to pass a health check to switch.
Special Enrollment Periods: Full Reference Table
| SEP Trigger | Window to Act | What You Can Change |
|---|---|---|
| Moving to new plan service area | 60 days from move date | Join new local MA plan or PDP |
| Losing employer/union coverage | 8 months (Part B); 63 days (Part D) | Enroll in Part B or any Part D plan |
| Qualifying for Extra Help / LIS | 60 days from notice | Switch to any Part D plan without penalty |
| Moving into/out of nursing home | 60 days from move | Change MA plan or return to Original Medicare |
| Your plan leaves Medicare | 60 days from notice | Enroll in any new plan |
| 5-Star plan available in area | Jan 1 – Nov 30 (once/year) | Switch to a 5-star MA plan any time |
Moving Almost Always Triggers a SEP
MA plans are tied to service areas. Moving to a new county or state typically means your plan no longer covers your area — immediately triggering a 60-day SEP. Contact your plan within 30 days of moving to start the process and avoid any coverage gap.
Returning to Original Medicare: The Medigap Problem
Switching from Medicare Advantage back to Original Medicare is possible during AEP or the MAOEP. However, getting a Medigap supplement afterward is not guaranteed. Outside your initial 6-month Medigap Open Enrollment Period, insurers can deny your Medigap application or charge higher rates based on your health history. The only exception is using your 12-month Trial Right — available only in the first year of your first-ever Medicare Advantage plan.
How to Make the Best of Any Enrollment Window
Read your Annual Notice of Change (ANOC) every September
Your plan mails a mandatory ANOC letter listing all premium, formulary, and benefit changes for the following year. This triggers your AEP review.
Verify your doctors and hospitals in October
Call each provider's office directly to confirm they're in-network for the plan you're considering. Online network directories can lag by weeks.
Run a drug comparison at Medicare.gov in October
Medicare.gov Plan Finder updates with next year's formularies in October. Enter all your prescriptions to see estimated annual costs across every plan in your area.
Submit your change before the deadline
For AEP: before December 7. For MAOEP: before March 31. If you change your mind, the last submitted application counts — you can revise during the window.
If Nothing Changed, Review Anyway
Even if your plan didn't announce changes, formularies shift and new plans launch every year. Spending 30 minutes on Medicare.gov Plan Finder in October could reveal a plan with a higher OTC card, better drug coverage, or the same coverage at a lower cost — money you're leaving on the table every year you skip the review.
Key Takeaways
- ✓Oct 15 - Dec 7 (AEP) is the most flexible time to make any change
- ✓Jan 1 - March 31 (MA OEP) is a 'second chance' for Advantage plan members
- ✓A move to a new state or county almost always triggers an SEP
- ✓Losing employer insurance gives you an 8-month window for Part B
- ✓Switching to a 5-star plan is allowed once per year outside of AEP
- ✓Most plan changes take effect on the first day of the following month
Frequently Asked Questions
Disclaimer: SeniorPop is not affiliated with Medicare, Medicaid, or any government agency. Benefit availability varies by plan and location. Contact a licensed Medicare advisor for plan-specific information.