You can enroll in a Medicare Advantage plan when you first become eligible for Medicare. This is called the Initial Coverage Election Period (ICEP). Your ICEP begins 3 months before the date you have both Medicare Part A and Part B for the first time and ends either on the last day of the month after the month in which you first have both Part A and Part B; or the last day of your Part B Initial Enrollment Period, whichever is later. Your coverage will begin the month you are eligible for Medicare or the 1st of the month following the month you elect your Medicare Advantage coverage during your ICEP, whichever is later.
You can also enroll in a Medicare Advantage plan during the Annual Enrollment Period (AEP). This is between October 15 and December 7 every year. Anyone with Medicare Part A and Part B can join, switch, or drop a Medicare Advantage plan during AEP. Your coverage begins on January 1 as long as you enroll between October 15 and midnight on December 7.
If you are already enrolled in a Medicare Advantage plan as of January 1, then you can make a one-time election to go to another Medicare Advantage plan or Original Medicare and make a coordinating change to add or drop Part D prescription drug coverage. This is called the Medicare Advantage Open Enrollment Period (MA OEP). It is between January 1 and March 31 each year.
Finally, you may also enroll in a Medicare Advantage plan at other times during the year if you qualify for a Special Enrollment Period (SEP). Your coverage start date depends on the election period you are eligible for. The most common SEPs happen when you lose group health insurance coverage, you move into an area with different plan options, you qualify for Extra Help with prescription drug costs, or you have a change in your Medicaid status.