Initial Enrollment Period (IEP)
Your first opportunity to enroll in Medicare generally begins three months before the month you turn 65, includes your birthday month, and continues for three months afterward.

Annual Enrollment Period (AEP)
October 15 through December 7 each year. During this period, eligible Medicare beneficiaries can review their coverage and make certain changes for the following year.

Medicare Advantage Open Enrollment Period (MA OEP)
January 1 through March 31. People already enrolled in a Medicare Advantage plan may have an opportunity to change Medicare Advantage plans or return to Original Medicare during this period.

Special Enrollment Periods (SEPs)
Certain life events or circumstances may provide an opportunity to make Medicare coverage changes outside the regular enrollment periods. Eligibility and timing depend on the specific situation.