U.S. Medicare enrollment deadlines for 2027 coverage

December 7 is the fall plan deadline

During the fall window, eligible people can switch between Original Medicare and Medicare Advantage, change Medicare Advantage plans, or change prescription drug coverage where eligible. Medicare requires the plan to receive the enrollment request by December 7 for a January 1 start. Source 1 Source 2

The January Medicare Advantage window is for existing members

From January 1 through March 31, someone already enrolled in Medicare Advantage can switch to another Medicare Advantage plan or return to Original Medicare and join a separate drug plan. A change normally takes effect on the first of the month after the plan receives the request. Source 2

The General Enrollment Period covers Part A and Part B sign-up

The January to March General Enrollment Period gives eligible people another chance to sign up for Part B or premium Part A after their initial opportunity. Coverage starts the following month. A late enrollment penalty can apply where the person does not qualify for an applicable Special Enrollment Period. Source 3

First-time and special enrollment follow individual dates

The standard age-65 sign-up window spans seven months. For someone whose birthday is on the first of a month, Medicare applies different timing rules. Certain events, including a move or a loss of coverage, can open a Special Enrollment Period for a plan. Medicare publishes separate rules for events that allow later Part A or Part B enrollment. Source 2 Source 3

Sources

• CMS announcement for 2027 Medicare plans
• Medicare health and drug plan enrollment periods
• Medicare Part A and Part B sign-up and coverage dates