When can I join a Medicare Advantage Plan?
You can join when you decide to get your Medicare coverage, you might want to choose a Medicare Advantage Plan (Part C) and/or Medicare prescription drug coverage (Part D).
There are specific times when you can sign up for a Medicare Advantage Plan, or make changes to coverage you already have.
You don’t need to sign up for Medicare each year. However, each year you’ll have a chance to review your coverage and change plans.
There are 2 separate enrollment periods each year: Open Enrollment period for medicare advantage and medicare prescription drug coverage which starts October 15 – December 7.
The other open enrollment period is for Medicare advantage open enrollment period which starts January 1 – March 31.
https://www.medicare.gov/sign-up-change-plans/joining-a-health-or-drug-plan