Medicare Advantage Open Enrollment Period 2027.

The window and who it is for

Medicare.gov lists the Medicare Advantage Open Enrollment Period as January 1 to March 31 and says it applies only if you are already in a Medicare Advantage Plan. In 2027 that is January 1 through March 31, 2027. If you are in Original Medicare, the fall window (October 15 to December 7) is your yearly chance, covered on the Medicare open enrollment checklist.

What you can do

• Switch to another Medicare Advantage Plan, with or without drug coverage.
• Drop your Medicare Advantage Plan and return to Original Medicare. You can also join a separate Medicare drug plan.

Coverage starts the first of the month after the plan gets your request to join (Medicare.gov).

You get one election

The regulation, 42 CFR 422.62(a)(3)(i), says a person enrolled in an MA plan may make an election once during the first three months of the year, to enroll in another MA plan or to disenroll to obtain Original Medicare. A person who uses it may also make a coordinating election to join or leave Part D. Pick the plan carefully: you cannot use this window a second time, and you cannot use it to go from Original Medicare into an Advantage plan.

That single-election limit does not apply to the fall annual election period or to special election periods (42 CFR 422.62(a)(3)(iii)).

Newly eligible people

A newly eligible Medicare Advantage member who joined during their Initial Enrollment Period gets a similar one-time change during the first three months they have both Part A and Part B (42 CFR 422.62(a)(3)(ii); Medicare.gov says the same). Use the initial enrollment period calculator to find your dates.

How to choose

1. List what the first months of the year showed you: drugs you actually fill, doctors you needed, bills you paid.
2. Compare the new plan's premium, deductible, drug tiers and yearly drug estimate on Medicare.gov's plan finder.
3. Confirm your doctors and pharmacies are in network for the plan you would move to.
4. If you are going back to Original Medicare, add a drug plan in the same request if you take medicines.

What this does not cover

• The fall Open Enrollment Period, which starts October 15 each year.
• Special Enrollment Periods for events such as moving or losing other coverage.
• Supplemental (Medigap) insurance rules, which differ by state and are not part of this window.

Sources

Retrieved 2026-11-01. Each page was opened and read against the claim next to it.

• Medicare.gov, Joining a plan: the January 1 to March 31 window, who qualifies, what you can do and coverage start.
• 42 CFR 422.62, election of coverage under an MA plan (Cornell LII): the one-time election, the coordinating Part D election and the newly eligible rule.