Most people first become eligible for Medicare during their Initial Enrollment Period (IEP) — a 7-month window that includes the 3 months before your 65th birthday, your birthday month itself, and the 3 months after. If you sign up in the 3 months before your birthday month, your coverage starts the first day of your birthday month. If you sign up in your birthday month or later, coverage is delayed by 1–3 months.
If you miss your IEP, you have other windows:
- General Enrollment Period (GEP): January 1 – March 31 each year. Coverage starts the month after you sign up. Late-enrollment penalties may apply for life if you didn't have other creditable coverage.
- Annual Enrollment Period (AEP): October 15 – December 7. This is for changing or picking a Medicare Advantage or Part D plan if you're already enrolled in Medicare. New plan starts January 1.
- Medicare Advantage Open Enrollment Period (OEP): January 1 – March 31. If you're already on Medicare Advantage, you can switch to a different MA plan once or return to Original Medicare.
- Special Enrollment Periods (SEPs): Year-round, triggered by qualifying life events — moving, losing employer coverage, your plan exiting your area, gaining/losing Medicaid eligibility, and others.
If you have employer health coverage at age 65 from current active employment (not retiree coverage), you can usually delay enrolling in Part B without penalty. When that coverage ends, an 8-month SEP opens for you to enroll. Confirm in writing with your employer that your coverage is creditable before relying on this — getting it wrong triggers a permanent late-enrollment penalty added to your Part B premium for the rest of your life.
What to do next: Call SilverEdge at (866) 534-1886 to confirm your enrollment window and walk through every Medicare plan option in your ZIP — free and no obligation.