The Basic Rule: Age 65 Is the Standard Start Date

You can start Medicare the month you turn 65, regardless of whether you are still working. Most people become may be able to access on the first day of the month in which they reach 65. If your birthday falls on the first of the month, your coverage begins that day. If your birthday is any other day, coverage starts the first day of the following month.

You do not have to retire to start Medicare. You can work full-time, part-time, or not at all — your work status does not change when you become may be able to access. However, you must sign up during your enrollment window, or you may face a permanent penalty on your premiums.

Key Takeaways

  • You become may be able to access for Medicare at 65, and coverage begins the first day of the month you turn 65 (or the month after, depending on your birthday).
  • If you are still working and have health insurance through your job, you may be able to delay Medicare Part B without penalty if your employer has 20 or more employees.
  • You must sign up during your Initial Enrollment Period — the seven-month window centered on your 65th birthday — or pay a permanent increase to your premiums.
  • Some people under 65 can start Medicare if they receive Social Security disability benefits or have end-stage renal disease or ALS.
  • Your enrollment window opens three months before the month you turn 65 and closes three months after.

When Your Enrollment Window Opens and Closes

Your Initial Enrollment Period is a seven-month window: it begins three months before the month you turn 65 and ends three months after. For example, if you turn 65 in June, your window runs from March through September.

You can sign up during any month in this window. The month you sign up does not determine when coverage starts — coverage always begins the first day of the month you turn 65 (or the month after, depending on your birthday). Signing up early straightforward gives you time to complete the process without rushing.

If you miss this window and do not have a may have access to reason to delay, you will pay a permanent 10% increase to your Part B premium for each full year you were may be able to access but not signed up. This penalty stays with you for life, even after you do sign up.

Working Past 65: When You Can Delay Part B

If you are still working and covered by your employer's health plan, you may be able to delay Medicare Part B without penalty. This option is available only if your employer has 20 or more employees. If your employer is smaller, you must sign up for Part B when you turn 65 or face the permanent penalty.

To use this exception, you must sign up for Part A (hospital insurance) at 65, but you can delay Part B (medical insurance) as long as you remain employed and covered by the employer plan. When you leave your job or lose the employer coverage, you have eight months to sign up for Part B without penalty. This eight-month period is called your Special Enrollment Period.

You still need to sign up for Part A during your Initial Enrollment Period, even if you delay Part B. Part A has no monthly premium for most people, so there is no cost to signing up early.

Medicare Before 65: Disability, End-Stage Renal Disease, and ALS

You can start Medicare before 65 if you receive Social Security Disability Insurance (SSDI) or Railroad Retirement Board disability benefits. You become may be able to access for Medicare after you have been receiving disability benefits for 24 consecutive months. Coverage begins in the 25th month of your disability benefit payments.

Two conditions bypass the 24-month waiting period. If you have end-stage renal disease (permanent kidney failure requiring dialysis or transplant), you can start Medicare as soon as your condition is diagnosed, regardless of your age or work history. If you have ALS (amyotrophic lateral sclerosis), you can start Medicare when ready upon diagnosis, with no waiting period.

If you receive disability benefits and turn 65, your Medicare coverage continues without interruption. Your coverage type changes from disability-based to age-based, but there is no gap or restart.

Signing Up: Where and How

You can sign up for Medicare through three main routes: online at Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office.

Have your Social Security number and birth certificate ready. If you are signing up for Part B, you will need to provide information about any current health coverage through an employer or spouse's employer. If you are delaying Part B because you are still working, bring documentation of your employer coverage — your insurance card or a letter from your employer stating the number of employees and your coverage dates.

The process usually takes 15 to 30 minutes by phone or online. You will receive a confirmation notice in the mail within two weeks. Your Medicare card arrives separately, typically within two to four weeks of approval.

What Happens If You Miss Your Enrollment Window

If you do not sign up during your Initial Enrollment Period and do not have a may have access to reason to delay (such as employer coverage), you can still sign up later. However, you will pay a permanent penalty on your Part B premium: 10% more for each full year you were may be able to access but not enrolled.

You can sign up during the General Enrollment Period, which runs January 1 through March 31 each year. Coverage begins July 1 of that year. This means if you miss your Initial Enrollment Period by one month and sign up in January, your new coverage does not start until July — a gap of several months.

If you have a may have access to life event — such as losing employer coverage, moving out of your service area, or a change in your immigration status — you may be able to sign up outside the normal windows without penalty. Contact Social Security or Medicare to ask about your specific situation.

Coordinating Medicare With Social Security

You do not have to claim Social Security retirement benefits when you turn 65 to start Medicare. These are separate programs. You can start Medicare at 65 and delay Social Security benefits until 70 to receive a higher monthly payment.

However, if you are already receiving Social Security benefits when you turn 65, you will be automatically enrolled in Medicare Part A and Part B. You will receive your Medicare card in the mail about three months before your 65th birthday. If you do not want Part B, you must actively decline it in writing.

If you have not yet claimed Social Security and do not want automatic enrollment, you can request it be delayed when you sign up for Medicare. You will need to sign a form stating you want Medicare but not Social Security retirement benefits.

Frequently Asked Questions

What if my birthday is on the first of the month?

Your Medicare coverage begins on your birthday itself — the first day of that month. Your enrollment window still opens three months before and closes three months after that month.

Can I start Medicare before I turn 65 if I am still working?

No, unless you receive disability benefits or have end-stage renal disease or ALS. Work status does not lower the age requirement. However, if you are working and covered by an employer plan with 20 or more employees, you can delay Part B without penalty.

Do I lose my employer health insurance when I turn 65?

No. Your employer coverage continues unless you or your employer end it. You can keep both Medicare and employer coverage. However, Medicare becomes your primary payer once you are enrolled, and your employer plan pays secondary.

What if I turn 65 while I am traveling outside the United States?

You can still sign up for Medicare during your enrollment window, even if you are outside the country. You can sign up online at Medicare.gov or by phone at 1-800-MEDICARE. Your coverage begins on schedule, though your card may take longer to arrive if you are not at a U.S. address.

Is there a penalty if I delay Part A?

No. Part A has no monthly premium for most people, so there is no penalty for delaying it. However, you must sign up during your Initial Enrollment Period to avoid complications with your Part B enrollment and to may support continuous coverage.