Definition. The Medicare Advantage Open Enrollment Period runs January 1 to March 31 each year. If you're already in a Medicare Advantage plan, you can make one change: switch to another Medicare Advantage plan, or drop it and return to Original Medicare (and join a stand-alone Part D plan).
What it means
The MA Open Enrollment Period (MA OEP) is separate from the fall Open Enrollment Period (October 15 to December 7). During the MA OEP, if you're enrolled in a Medicare Advantage plan, you can:
- Switch to a different Medicare Advantage plan, with or without drug coverage.
- Drop your Medicare Advantage plan, return to Original Medicare, and join a stand-alone Part D drug plan.
You get one change during the period. The MA OEP does not let you move from Original Medicare into Medicare Advantage, and it doesn't let you switch from one stand-alone Part D plan to another while staying on Original Medicare. If you're new to Medicare and joined a Medicare Advantage plan when you first got Medicare, you can also make one change during your first three months of Medicare. A change takes effect the first day of the month after the plan gets your request.
In Oregon
Several companies stop offering Medicare Advantage plans in some Oregon counties for 2027. If your plan isn't renewing, you don't need the MA OEP: you have a Special Enrollment Period through February 28, 2027, and a 63-day Medigap guaranteed-issue right after the plan ends. See Medicare plans ending in Oregon for 2027. Five Oregon counties (Grant, Harney, Lake, Umatilla and Union) have no Medicare Advantage plan open to everyone for 2027, so check your county's page before you plan a switch.
Sources
- Medicare.gov — Joining a health or drug plan
- 42 CFR 422.62 — Election of coverage under an MA plan
- Oregon Administrative Rules 836-052-0142 — Medigap guaranteed issue
Frequently asked questions
If I switch back to Original Medicare during the MA OEP, can I get a Medigap policy?
Not automatically. You have a guaranteed right to buy Medigap only in specific cases, such as a trial right if you joined Medicare Advantage for the first time within the last 12 months. In Oregon, once you have a Medigap policy, the birthday rule lets you switch each year to one with the same or lesser benefits.
Can I use the MA OEP to move from Original Medicare into Medicare Advantage?
No. The MA OEP is only for people already enrolled in a Medicare Advantage plan. To join Medicare Advantage from Original Medicare, use Open Enrollment (October 15 to December 7) or a Special Enrollment Period.
My Medicare Advantage plan is ending in 2027. Do I need the MA OEP?
Usually not. If your plan isn't renewing, you have a Special Enrollment Period through February 28, 2027. Choose a new plan by December 31, 2026 to avoid a gap in coverage.
Medicare in your Oregon county
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