The Initial Coverage Election Period (ICEP) is a period of time that begins the three months immediately before you are entitled to Medicare Part A and enrolled in Part B and ends either the last day of the month before you are entitled to Part A and enrolled in Part B or three months after the month of your 65th birthday or the 25th month of receiving Social Security Disability Insurance (SSDI). If you choose to join a Medicare Advantage Plan during this period, the plan must accept you, unless it has reached its member limit.