Initial Coverage Election Period

The 3 months immediately before you are entitled to Medicare Part A and enrolled in Part B. You may choose a Medicare health plan during your Initial Coverage Election Period. The plan must accept you unless it has reached its limit in the number of members. This limit is approved by the Centers for Medicare & Medicaid Services. The Initial Coverage Election Period is different from the Initial Enrollment Period (IEP). (See Election Periods; Enrollment/Part A; Initial Enrollment Period (IEP).)

Source: Medicare.gov