Medicare enrollment window calculator
Enter your birth date. The calculator shows when you turn 65 and the seven-month window for your Medicare Initial Enrollment Period: the three months before the month you turn 65, that month, and the three months after.
Rules checked
Your Initial Enrollment Period
December 1, 2026 to June 30, 2027
You turn 65 on March 15, 2027. Sign up before March 2027 and coverage starts on March 1, 2027.
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This is an estimate for general information, not an insurance quote or advice. Confirm dates and costs with your plan, your marketplace or Medicare.
We do not offer every plan available in your area. Any information we provide is limited to those plans we do offer in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options.
How is the window worked out?
Your Initial Enrollment Period begins three months before the month you turn 65 and ends three months after it. If your birthday is on the first of the month, Medicare counts your birthday month as the month before, so the window moves one month earlier.
Why does the timing matter?
If you sign up before the month you turn 65, coverage starts the first day of your birthday month. Waiting until after your window can mean gaps in coverage and late penalties on Part B and Part D in many cases. People who still have job-based coverage may have other options, so ask before you delay.
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Common questions
How long is the Initial Enrollment Period?
Seven months: three months before the month you turn 65, the month you turn 65 and three months after.
What if I turn 65 on the first of a month?
Medicare treats your birthday month as the month before, so your window and your coverage start date move one month earlier.
Does this apply if I get Medicare because of a disability?
No. Different rules apply if you qualify before 65. Ask Social Security or a licensed agent.
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