You get a 7‑month Initial Enrollment Period (IEP): starts 3 months before your 65th birthday, includes your birth month, and ends 3 months after.If you’re still working and have employer‑based coverage, there are Special Enrollment Periods that may allow delay without penalty.If you miss the IEP and aren’t eligible for a Special Enrollment Period, you’ll have to wait for the General Enrollment Period (Jan 1 – March 31), and coverage starts July 1.