When You Can Enroll in Medicare: Age, Disability, and Other Pathways

The Main Routes to Medicare Enrollment

You can enroll in Medicare when you turn 65, regardless of your work history or income. You do not have to retire. If you are already receiving Social Security benefits when you turn 65, Medicare enrollment happens automatically. If you are not yet receiving Social Security, you will need to sign up for Medicare separately through Social Security, Medicare.gov, or your local Social Security office.

You can also enroll in Medicare before age 65 if you have received Social Security Disability Insurance (SSDI) for 24 consecutive months, or if you have End-Stage Renal Disease (ESRD) or Amyotrophic Lateral Sclerosis (ALS). These three conditions are the only medical reasons Medicare covers people under 65.

If you are still working at 65 and have health insurance through your employer, you may delay Medicare enrollment without penalty, but the rules depend on your employer's size and your spouse's age. Delaying past 65 without this coverage can result in a permanent premium increase.

Key Takeaways

You become may be able to access for Medicare on the first day of the month you turn 65, and you can enroll during the three months before and three months after your birthday.
If you receive SSDI for 24 months, you become may be able to access at age 65 regardless of when those 24 months occurred, and Medicare begins automatically two years after your SSDI started.
People with End-Stage Renal Disease or ALS can enroll in Medicare at any age, and enrollment timing depends on when treatment begins or the diagnosis is made.
Delaying Medicare enrollment past 65 without employer coverage results in a permanent 10 percent premium increase for each year you wait, and this penalty lasts for life.
Your initial enrollment period is seven months long (three months before your 65th birthday, the month of your birthday, and three months after), and missing this window means waiting until the general enrollment period in January through March.

Enrollment at Age 65: The Standard Timeline

Your Initial Enrollment Period begins three months before the month you turn 65 and ends three months after. If your birthday is June 15, your enrollment period runs from March 1 through September 30. You can enroll any time during these seven months, and your coverage will begin on the first day of the month you turn 65, regardless of when during that month your birthday falls.

If you miss your Initial Enrollment Period, you enter the General Enrollment Period, which runs January 1 through March 31 each year. Coverage begins July 1 of that year. However, you will pay a permanent 10 percent premium increase for each full year you delayed past 65. This penalty applies to Part B (medical insurance) and Part D (prescription drug coverage) and never goes away, even if you enroll years later.

The exception is if you had creditable coverage through an employer or union when you turned 65. Creditable coverage means your plan was at least as good as Medicare. If you had this coverage, you can delay enrollment without penalty as long as you enroll within eight months of losing that coverage. You will need to provide proof of your previous coverage when you sign up.

Disability Before Age 65: The 24-Month SSDI Rule

If you receive Social Security Disability Insurance (SSDI), you become may be able to access for Medicare after you have received SSDI for 24 consecutive months. The 24 months do not have to be recent — if you received SSDI years ago, stopped, and then restarted, only the most recent continuous period counts. Once you have been on SSDI for 24 months, Medicare enrollment happens automatically, and your coverage begins two years after your SSDI start date.

You do not need to do anything to enroll. Social Security will send you a Medicare card in the mail about three months before your coverage begins. If you do not receive a card, contact Social Security at 1-800-772-1213 to confirm your enrollment. Your Medicare coverage will include Part A (hospital insurance) and Part B (medical insurance) automatically, though you can decline Part B if you have other coverage.

If you are unsure whether your condition qualifies for SSDI, or whether you have been receiving benefits long enough, Social Security can tell you your exact may be able to access date. Call 1-800-772-1213 or visit your local Social Security office with your SSDI award letter.

End-Stage Renal Disease and ALS: when ready may be able to access

You can enroll in Medicare at any age if you have End-Stage Renal Disease (ESRD) — permanent kidney failure requiring dialysis or a transplant. Your enrollment timing depends on when your treatment begins. If you start dialysis, Medicare coverage begins the first day of the month you start treatment. If you receive a kidney transplant before starting dialysis, Medicare begins the month of your transplant. If you are already on dialysis when you turn 65, your Medicare coverage continues without interruption.

You can also enroll at any age if you have Amyotrophic Lateral Sclerosis (ALS), also called Lou Gehrig's disease. Unlike SSDI, you do not have to wait 24 months. Medicare coverage begins the first day of the month after you are approved for SSDI based on an ALS diagnosis. Your dialysis center or ALS clinic can help you understand your enrollment date and submit the necessary paperwork to Social Security.

For both ESRD and ALS, you should contact Social Security or Medicare as soon as you receive your diagnosis or begin treatment. Medicare will work backward to cover medical costs from your treatment start date, even if you enroll months later, so do not delay reporting your condition.

Working Past 65 and Employer Coverage

If you are still working at 65 and your employer has 20 or more employees, you can delay Medicare Part B enrollment without penalty. Your employer's health plan is considered primary, meaning it pays first, and Medicare pays second. You must enroll in Medicare Part B within eight months of leaving your job or losing your employer coverage, or you will face a permanent premium increase.

If your employer has fewer than 20 employees, Medicare becomes primary when ready at 65, even if you are still working. You should enroll in Medicare Part B when you turn 65 to avoid gaps in coverage. Part A (hospital insurance) has no premium and no penalty for late enrollment, so you can enroll in Part A at any time.

If your spouse is still working and you are covered under their employer plan, different rules explore depending on your spouse's age and your relationship to their employer. Contact Medicare at 1-800-MEDICARE (1-800-633-4227) to discuss your specific situation before you turn 65.

Special Circumstances: Deemed Filing and Deemed Enrollment

If you are already receiving Social Security retirement benefits when you turn 65, Medicare enrollment is automatic. You do not need to do anything. Social Security will send you a Medicare card about three months before your coverage begins on your 65th birthday. If you do not receive a card, contact Social Security to confirm.

If you are receiving Supplemental Security Income (SSI) — a needs-based program separate from SSDI — you also enroll automatically in Medicare at 65. The same automatic enrollment applies if you are receiving Railroad Retirement benefits. In all these cases, you will receive your Medicare card by mail without having to submit an process.

If you miss your Initial Enrollment Period and do not have creditable coverage, you can still enroll during the General Enrollment Period (January 1 through March 31), but your coverage will not begin until July 1, and you will pay a permanent premium penalty. The only way to avoid this penalty after missing your initial window is to prove you had creditable coverage when you turned 65.

How to Enroll: Three Main Routes

You can enroll in Medicare through Social Security, Medicare.gov, or your local Social Security office. If you are already receiving Social Security benefits, you do not need to do anything — enrollment is automatic. If you are not yet receiving Social Security, you have three options.

Online at Medicare.gov: Visit Medicare.gov/sign-up and follow the enrollment steps. You will need your Social Security number, date of birth, and citizenship information. You can enroll this way starting three months before your 65th birthday. Your process is processed within 30 days, and you will receive your Medicare card by mail.

By phone: Call Social Security at 1-800-772-1213 (TTY 1-800-325-0778). Representatives are available Monday through Friday, 7 a.m. to 7 p.m. Eastern time. Have your Social Security number and date of birth ready. Social Security will mail you an process form, which you sign and return. Processing takes about 30 days from when Social Security receives your completed form.

In person: Visit your local Social Security office. Bring your Social Security card, birth certificate, and proof of citizenship (passport, naturalization certificate, or state ID). You can enroll anytime during your Initial Enrollment Period. Social Security will give you a receipt and mail your Medicare card within 30 days.

Frequently Asked Questions

What happens if I turn 65 while still working?

You can delay Part B enrollment without penalty if your employer has 20 or more employees and you are covered under their health plan. You must enroll in Part B within eight months of leaving your job or losing coverage. Part A has no penalty for late enrollment. If your employer has fewer than 20 employees, you should enroll in Part B at 65 because Medicare becomes primary when ready.

Can I get Medicare if I have never worked?

Yes. You become may be able to access at 65 based on age alone, regardless of your work history or contributions to Social Security. You will receive Part A (hospital insurance) at no cost. Part B (medical insurance) has a monthly premium based on your income. You do not need to have worked to enroll.

What if I am on SSDI but not yet 24 months in?

You will become may be able to access for Medicare once you have received SSDI for 24 consecutive months. Medicare enrollment happens automatically, and coverage begins two years after your SSDI start date. You do not need to do anything. Social Security will send you a Medicare card by mail.

Do I have to enroll in Part D when I turn 65?

Part D (prescription drug coverage) is optional, but if you do not enroll when you turn 65 and you do not have other creditable drug coverage, you will pay a permanent premium increase when you do enroll. The increase is about 1 percent per month for each month you delayed. If you do not take prescription drugs, you can decline Part D without penalty.

What if I miss my enrollment period by a few months?

You can still enroll during the General Enrollment Period (January 1 through March 31 each year), but your coverage will not begin until July 1, and you will pay a permanent 10 percent premium increase for each full year you delayed past 65. This penalty lasts for life. The only exception is if you had creditable coverage through an employer when you turned 65.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.