Your Initial Enrollment Period (IEP) is the 7-month period you have when you first become eligible to sign up for Medicare. It includes the 3 months before the month of your birthday, your birth month, and the 3 months after the month of your birthday.
During this time, you can sign up for Medicare Part A, Part B, Medicare Advantage, and Part D.
If you sign up before your birth month, your coverage starts the first day of your birth month. If you sign up after the start of your birth month, your coverage starts the first day of the next month.