Medicare Enrollment Timing Checker
Enter your birth date below. We'll show you exactly when you can enroll, switch, or make changes — and what late penalties to watch for.
Your Medicare Enrollment Windows
How Medicare enrollment timing works
Medicare has a handful of enrollment windows, and missing them can mean permanent late penalties. Here's what each window is and why it matters.
Initial Enrollment Period (IEP)
A 7-month window around your 65th birthday: the 3 months before your birth month, your birth month, and the 3 months after. Most people enroll in Part A and Part B during this window. Sign up before the month you turn 65 to have coverage start on your 65th birthday.
Medigap Open Enrollment
The 6 months starting the month you turn 65 and are enrolled in Part B. During this window, no Medicare Supplement carrier can turn you down or charge more based on health. This is the cheapest window of your life to lock in a Medigap policy.
Annual Enrollment Period (AEP)
October 15 through December 7 every year. You can switch Medicare Advantage plans, switch Part D drug plans, or move between Original Medicare + Supplement and Advantage. Changes take effect January 1.
Open Enrollment Period (OEP)
January 1 through March 31. If you're already on Medicare Advantage, you can make one switch during this window (to a different MA plan, or back to Original Medicare + a Part D plan).
General Enrollment Period
January 1 through March 31. If you missed your IEP and don't qualify for a Special Enrollment Period, this is your chance to enroll in Part B. Late penalties usually apply.