Medicare IEP Calculator

This page turns your birthday into the seven-month Initial Enrollment Period for Medicare Part A and Part B. Choose a birth month and birth year, press Calculate, and it lays out all seven months in order — the three before your birthday month, the birthday month itself, and the three after — then names the first and last month of the window.

It adds two rules you can act on. Enrolling in the first three months starts coverage on the first of your birthday month; enrolling in your birthday month or later pushes coverage to the first of the month after you sign up. And missing the window without a qualifying exception adds ten percent to your Part B premium for each full twelve-month period you were eligible and not enrolled, permanently.

All it needs is the month and year you were born. One optional switch, for people with — or recently off — active employer coverage, adds the Special Enrollment Period rules: the eight-month window that opens the month after the job or that coverage ends, whichever comes first, and the warning that COBRA and retiree coverage do not count.

It does not ask the day of the month, so it will not apply Medicare's rule for people born on the first, whose window starts a month earlier. It is an estimate; an optional form invites a callback. It quotes no premium, compares no plans, and cannot enroll anyone — Social Security sets your real dates.

Born on the first? Use the Turning-65 Timeline next.