Enrollment Period Enrollment Dates Who can enroll Effective Date
AEP or Annual Enrollment Period Oct. 15th to Dec. 7th Medicare eligible January 1st


IEP or Initial Enrollment Period

3 months before 65th birthday, month of birthday and 3 months after 

First eligible for Medicare Month of birthday or Month following enrollment


SEP or Special Enrollment Period within 60 days of a triggering event Beneficiaries who experience a trigger event 1st of the month following enrollment
General Enrollment Period* Jan. 1 to March 31st MA or MA-PD beneficiaries 1st of the month following enrollment

*only for those enrolled on a Medicare Advantage plan