When to Enroll in Medicare — Don't Miss Your Window

Missing a Medicare enrollment deadline can mean penalties that follow you for life. Here are the key windows you need to know.

Initial Enrollment Period (IEP): A 7-month window around your 65th birthday — 3 months before, your birthday month, and 3 months after. This is your primary opportunity to enroll without any penalty.

General Enrollment Period (GEP): January 1 – March 31 each year. If you missed your IEP, this is your backup — but you'll pay a late enrollment penalty of 10% per year you were eligible but didn't enroll.

Special Enrollment Period (SEP): If you have employer coverage through your job (or a spouse's job) when you turn 65, you can delay Medicare without penalty and enroll within 8 months of losing that coverage.

Annual Enrollment Period (AEP): October 15 – December 7. This is when you can switch between Medicare Advantage plans, or switch between Medicare Advantage and Original Medicare. Changes take effect January 1.

Medicare Advantage Open Enrollment: January 1 – March 31. If you're already on a Medicare Advantage plan, you can switch to a different one or return to Original Medicare.

The Late Enrollment Penalty: For Part B, it's 10% added to your premium for each full 12-month period you were eligible but didn't enroll — and it's permanent. For Part D, it's 1% per month you were without creditable drug coverage.