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When is my Medicare eligibility?

Type your date of birth to see your Medicare eligibility at 65 and your Initial Enrollment Period. Add the date you sign up, and the Medicare eligibility calculator shows when your Part B coverage starts.

Your numbers

Earliest coverage start
November 1, 2026

Born on November 20, 1961, you turn 65 on November 20, 2026; your Initial Enrollment Period runs from August 1, 2026 to February 28, 2027, and Medicare can start on November 1, 2026.

You turn 65 on
November 20, 2026
Initial Enrollment Period opens
August 1, 2026
Initial Enrollment Period closes
February 28, 2027
Sign up by
October 31, 2026
Coverage starts
November 1, 2026
Your sign-up falls in
Initial Enrollment Period, before the month you turn 65

Earliest coverage start: November 1, 2026. Born on November 20, 1961, you turn 65 on November 20, 2026; your Initial Enrollment Period runs from August 1, 2026 to February 28, 2027, and Medicare can start on November 1, 2026.

When can you sign up, and when does coverage start?

The results are estimates for information only. They are not financial, tax, or legal advice. Check the numbers with your lender or a qualified professional before you decide. Terms of use

How to calculate

Works out when you can get Medicare at 65 from your date of birth: your 7-month Initial Enrollment Period, the earliest coverage date, and when Part B starts for the date you sign up.

Example with the default inputs (Date of birth November 20, 1961, Date you sign up (optional) September 10, 2026): Born on November 20, 1961, you turn 65 on November 20, 2026; your Initial Enrollment Period runs from August 1, 2026 to February 28, 2027, and Medicare can start on November 1, 2026.

Method: You attain 65 the day before your 65th birthday. Initial Enrollment Period = the first day of the 3rd month before that month to the last day of the 3rd month after it. Sign up in its first 3 months: coverage starts the first day of the month you attain 65; in its last 4 months: the first day of the month after you sign up. General Enrollment Period (January 1 to March 31): the month after you sign up, plus 10% Part B penalty for each full 12 months after the Initial Enrollment Period.

  • Medicare at age 65, not Medicare through disability benefits, ALS or end-stage renal disease.
  • If you start Social Security benefits at least 4 months before you turn 65, you get Parts A and B automatically from the first day of the month you attain 65.
  • Coverage dates are for Part B (and Part A you buy); premium-free Part A has its own start rules. Special Enrollment Periods (for example after job-based coverage ends) are not covered.
  • Birth dates from 1900 to 2100, sign-up dates to 2200.

Machine-readable copies: Markdown, JSON.

Worked examples

Each example is checked against the calculator on every build.

  1. Date of birth 1961-11-20, Date you sign up (optional) 2026-09-10 gives You turn 65 on 2026-11-20, Earliest coverage start 2026-11-01, Initial Enrollment Period opens 2026-08-01, Initial Enrollment Period closes 2027-02-28, Sign up by 2026-10-31, Coverage starts 2026-11-01.Source: 42 CFR 406.21 (7-month Initial Enrollment Period; General Enrollment Period January 1 to March 31) and 407.25(a)(2) (coverage start for enrollments on or after January 1, 2023), https://www.law.cornell.edu/cfr/text/42/407.25; Medicare.gov, When does Medicare coverage start? (Initial Enrollment Period; a birthday on the 1st starts coverage the month before), https://www.medicare.gov/basics/get-started-with-medicare/sign-up/when-does-medicare-coverage-start
  2. Date of birth 1961-07-01, Date you sign up (optional) 2026-07-15 gives You turn 65 on 2026-07-01, Earliest coverage start 2026-06-01, Initial Enrollment Period opens 2026-03-01, Initial Enrollment Period closes 2026-09-30, Coverage starts 2026-08-01.Source: Medicare.gov, When does Medicare coverage start? (Initial Enrollment Period; a birthday on the 1st starts coverage the month before), https://www.medicare.gov/basics/get-started-with-medicare/sign-up/when-does-medicare-coverage-start (a birthday on the first of the month); 20 CFR 404.2(c)(4): an individual attains an age on the day before the anniversary of birth, https://www.law.cornell.edu/cfr/text/20/404.2; 42 CFR 406.21 (7-month Initial Enrollment Period; General Enrollment Period January 1 to March 31) and 407.25(a)(2) (coverage start for enrollments on or after January 1, 2023), https://www.law.cornell.edu/cfr/text/42/407.25
  3. Date of birth 1960-02-29 gives You turn 65 on 2025-02-28, Earliest coverage start 2025-02-01, Initial Enrollment Period opens 2024-11-01, Initial Enrollment Period closes 2025-05-31.Source: 42 CFR 406.21 (7-month Initial Enrollment Period; General Enrollment Period January 1 to March 31) and 407.25(a)(2) (coverage start for enrollments on or after January 1, 2023), https://www.law.cornell.edu/cfr/text/42/407.25; 20 CFR 404.2(c)(4): an individual attains an age on the day before the anniversary of birth, https://www.law.cornell.edu/cfr/text/20/404.2
  4. Date of birth 1960-05-20, Date you sign up (optional) 2027-02-10 gives Initial Enrollment Period closes 2025-08-31, Coverage starts 2027-03-01, Part B late penalty 10%.Source: 42 CFR 406.21 (7-month Initial Enrollment Period; General Enrollment Period January 1 to March 31) and 407.25(a)(2) (coverage start for enrollments on or after January 1, 2023), https://www.law.cornell.edu/cfr/text/42/407.25 (406.21(c): coverage the month after you sign up); 42 CFR 408.22 and 408.24(b) (10% for each full 12 months from the close of the Initial Enrollment Period to the close of the month you enroll), https://www.law.cornell.edu/cfr/text/42/408.24; Medicare.gov, Avoid late enrollment penalties, https://www.medicare.gov/basics/costs/medicare-costs/avoid-penalties

How it works

All dates are calendar dates, with no time zone.

  1. You turn 65 on your date of birth plus 65 years. A February 29 birthday falls on February 28 in a year that is not a leap year.
  2. You attain 65 on the day before your 65th birthday (20 CFR 404.2(c)(4)). The month that day falls in is your month of eligibility: your birthday month, or the month before it if you were born on the 1st.
  3. Earliest coverage start = the first day of the month of eligibility.
  4. Initial Enrollment Period opens = the first day of the 3rd month before the month of eligibility.
  5. Initial Enrollment Period closes = the last day of the 3rd month after the month of eligibility (7 months in all).
  6. Sign up by = the day before the earliest coverage start: the last day to sign up and still start coverage then.
  7. Coverage starts, for a sign-up date you type:
    • before the Initial Enrollment Period opens: no answer ("You cannot sign up before your Initial Enrollment Period opens, 3 months before the month you turn 65.");
    • in the 3 months before the month of eligibility: the earliest coverage start, and Your sign-up falls in reads "Initial Enrollment Period, before the month you turn 65";
    • in the month of eligibility or the 3 months after it: the first day of the month after the sign-up date ("Initial Enrollment Period, from the month you turn 65");
    • after the Initial Enrollment Period, in January, February or March: the first day of the month after the sign-up date ("General Enrollment Period (January 1 to March 31)");
    • after the Initial Enrollment Period, in April to December: no answer ("After your Initial Enrollment Period you can sign up only from January 1 to March 31 (the General Enrollment Period), unless you have a Special Enrollment Period.").
  8. Part B late penalty (General Enrollment Period only) = 10% × the number of full 12-month periods in the months counted from the month after the Initial Enrollment Period closes through the month you sign up. In month numbers (year × 12 + month): ⌊(sign-up month − closing month) ÷ 12⌋ × 10%.

Birth dates run from January 1, 1900 to December 31, 2100 and sign-up dates to December 31, 2200.

Worked examples by hand

Born November 20, 1961, signing up September 10, 2026. You turn 65 on November 20, 2026 and attain 65 on November 19, so the month of eligibility is November 2026: coverage can start November 1, 2026. The Initial Enrollment Period runs from August 1, 2026 (3 months before) to February 28, 2027 (the end of the 3rd month after). September is in the first 3 months, so coverage starts November 1, 2026; the last day to sign up for that is October 31, 2026.

Born July 1, 1961, signing up July 15, 2026. You turn 65 on July 1, 2026 but attain 65 on June 30, so the month of eligibility is June 2026: coverage can start June 1, 2026, and the Initial Enrollment Period runs from March 1 to September 30, 2026. July is the month after the month of eligibility, so coverage starts August 1, 2026.

Born February 29, 1960. The 65th birthday is February 28, 2025; you attain 65 on February 27, so coverage can start February 1, 2025 and the Initial Enrollment Period runs from November 1, 2024 to May 31, 2025.

Born May 20, 1960, signing up February 10, 2027. The Initial Enrollment Period closed on August 31, 2025. February 2027 is in the General Enrollment Period, so coverage starts March 1, 2027. Months counted: September 2025 through February 2027 = 18, which holds 1 full 12-month period, so the Part B late penalty is 10%.

Other questions people ask

When am I eligible for Medicare?

Most people become eligible for Medicare in the month they turn 65. Medicare counts you as 65 on the day before your 65th birthday, so if you were born on the 1st of a month, you are eligible from the month before. People under 65 can qualify through disability benefits, ALS or end-stage renal disease.

What is the Initial Enrollment Period?

It is the 7 months around the month you turn 65: the 3 months before, that month, and the 3 months after (42 CFR 406.21 and 407.14). Turning 65 on November 20, 2026, your Initial Enrollment Period runs from August 1, 2026 to February 28, 2027.

When does coverage start if I sign up during the Initial Enrollment Period?

Sign up in the 3 months before the month you turn 65 and coverage starts on the first day of that month. Sign up in that month or the 3 months after it and coverage starts on the first day of the month after you sign up (42 CFR 407.25, for sign-ups from 2023).

What if I miss my Initial Enrollment Period?

You can sign up in the General Enrollment Period, January 1 to March 31 each year, and coverage starts the month after you sign up. Unless you had a Special Enrollment Period, your Part B premium goes up 10% for each full 12 months you could have had Part B but did not, for as long as you have Part B.

How is the Part B late penalty counted?

The months run from the end of your Initial Enrollment Period to the end of the month you sign up, and each full 12 months adds 10% (42 CFR 408.22 and 408.24(b)). If your Initial Enrollment Period ended on August 31, 2025 and you sign up in February 2027, that is 18 months: 1 full year, so 10%.

Am I enrolled automatically?

Yes, if you start getting Social Security benefits at least 4 months before you turn 65: you get Part A and Part B automatically, and your Medicare card arrives about 3 months before coverage starts, which is the first day of the month you turn 65. Otherwise you sign up with Social Security.

Do I have to sign up for Part B at 65 if I still work?

Not if you or your spouse have health coverage through a current job. You can then sign up any time while you work there, or within 8 months after the job or the coverage ends, whichever comes first, with no penalty (COBRA does not extend it). This calculator does not cover Special Enrollment Periods.