When You Can Start Medicare: Age Requirements and Your Options

You can start Medicare at age 65, or earlier if you have certain disabilities or conditions

Medicare may be able to access is tied to age 65 for most people, but the program also covers some younger adults. If you turn 65, you become may be able to access for Medicare Part A (hospital insurance) and Part B (medical insurance) regardless of your work history or income. The enrollment window opens three months before the month you turn 65 and closes three months after, so you have a seven-month window to sign up without penalties.

If you are under 65, you may still be able to start Medicare if you have been receiving Social Security Disability Insurance (SSDI) for 24 months, have end-stage renal disease (ESRD), or have amyotrophic lateral sclerosis (ALS). Each of these routes has different timing and requirements, and understanding which one applies to you matters because missing the enrollment window can cost you in late-enrollment penalties.

Key Takeaways

You become may be able to access for Medicare at age 65, with a seven-month enrollment window that starts three months before your birthday.
If you are under 65 and have received SSDI for 24 consecutive months, you may be able to start Medicare without waiting until 65.
People with end-stage renal disease or ALS can start Medicare at any age, but timing depends on when you begin dialysis, receive a transplant, or are diagnosed.
Delaying enrollment past your window can result in a permanent 10 percent increase to your Part B premium for each year you waited.
You must actively enroll in Medicare; it does not happen automatically even if you are already receiving Social Security.

Turning 65: The standard Medicare age and enrollment window

Age 65 is the age at which most people become may be able to access for Medicare. You do not have to be retired, and you do not have to have worked a certain number of years—if you are a U.S. citizen or permanent resident and have lived in the country for at least five years, you can enroll. The enrollment window is seven months long: it begins three months before the month you turn 65 and ends three months after.

For example, if you turn 65 in June, your enrollment window runs from March through September. You can enroll online through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office. If you miss this window and do not have a may have access to life event (such as losing employer coverage), you will pay a late-enrollment penalty on your Part B premium for as long as you have Medicare.

Under 65 with SSDI: The 24-month rule

If you have been receiving Social Security Disability Insurance for 24 consecutive months, you become may be able to access for Medicare even if you are under 65. The 24 months do not have to be recent—they can be any 24 months since you first started receiving SSDI. Once you hit that 24-month mark, Medicare begins automatically; you do not have to explore separately.

The timing matters because your Medicare coverage starts on the first day of the month in which you complete 24 months of SSDI. Social Security will notify you by mail when you become may be able to access, usually a few months before your coverage begins. If you are already receiving SSDI and approaching 24 months, check your Social Security statement online or call 1-800-772-1213 to confirm your start date.

End-stage renal disease: Medicare at any age

If you have end-stage renal disease (ESRD)—permanent kidney failure requiring dialysis or a transplant—you can start Medicare at any age. Your may be able to access date depends on which treatment you receive. If you begin dialysis, Medicare coverage starts on the first day of the fourth month after you begin treatment. If you receive a kidney transplant, coverage begins the month of your transplant.

You must enroll in Medicare within 12 months of starting dialysis or receiving a transplant, or you may face late-enrollment penalties. Your nephrologist's office or dialysis center can help you understand your timeline and connect you with enrollment resources. If you are already on dialysis or have had a transplant, contact Medicare directly at 1-800-MEDICARE to confirm your may be able to access date.

ALS: when ready Medicare may be able to access

Amyotrophic lateral sclerosis (ALS) is the only condition that makes you may be able to access for Medicare when ready upon diagnosis, without a waiting period. You do not have to wait 24 months like SSDI recipients. Your Medicare coverage begins the first day of the month in which you are diagnosed, and Social Security will contact you to enroll.

Because ALS progresses quickly, this when ready may be able to access is designed to remove barriers to coverage. If you have been diagnosed with ALS, your doctor or the ALS Association can help you navigate enrollment. You can also contact Social Security at 1-800-772-1213 to confirm your coverage start date and may support your enrollment is processed.

What happens if you miss your enrollment window

If you turn 65 and do not enroll in Medicare during your seven-month window, you will owe a late-enrollment penalty on Part B. The penalty is 10 percent of the standard Part B premium for each full year you could have been enrolled but were not. This penalty is permanent—it stays on your premium for as long as you have Medicare.

There are limited exceptions. If you had employer coverage through your job or your spouse's job when you turned 65, you may not owe a penalty, but you must be able to prove it. If you lose that coverage, you have eight months to enroll in Medicare without penalty. If you are unsure whether you may have access to for an exception, contact Medicare at 1-800-MEDICARE before enrolling; they can review your situation.

Enrolling before 65 if you are still working

You can enroll in Medicare before you turn 65 if you meet one of the earlier-may be able to access conditions (SSDI, ESRD, or ALS), but you do not have to if you are still working and covered by your employer's health plan. Many people choose to delay Part B enrollment while they work, as long as their employer has 20 or more employees. When you eventually leave that job or lose coverage, you have eight months to enroll without penalty.

Part A (hospital insurance) is different. If you are may be able to access for Medicare before 65 due to SSDI, ESRD, or ALS, Part A enrollment is automatic and you cannot delay it. Part B is optional during this period if you have employer coverage, but you should review your options carefully—delaying Part B when you do not have may have access to employer coverage will result in penalties.

How to enroll in Medicare

You can enroll through three main channels: online at Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office. Online enrollment is the fastest option and you can complete it in about 10 minutes. By phone, a representative can walk you through the process and answer questions; wait times vary but the line is open Monday through Friday, 8 a.m. to 7 p.m. Eastern time.

If you are already receiving Social Security benefits, you can enroll online using your Social Security account. If you are not yet receiving benefits, you will need to create a Medicare.gov account. Have your Social Security number, citizenship or immigration status documentation, and information about any current health coverage ready when you enroll. If you enroll online or by phone, you should receive a Medicare card in the mail within two to three weeks.

Frequently Asked Questions

Do I have to enroll in Medicare at 65 if I am still working?

If your employer has 20 or more employees and you are covered by their health plan, you do not have to enroll in Part B at 65. However, you must enroll in Part A. When you leave that job or lose coverage, you have eight months to enroll in Part B without penalty. If your employer has fewer than 20 employees, you should enroll in Medicare at 65 even if you are working.

What if I turn 65 and do not enroll because I did not know I had to?

You will owe a late-enrollment penalty on Part B unless you had may have access to employer coverage. The penalty is 10 percent of the standard Part B premium for each year you could have been enrolled. You can still enroll, but the penalty will be permanent. Contact Medicare at 1-800-MEDICARE to discuss your situation and whether any exceptions explore to you.

If I am on SSDI, do I have to do anything to get Medicare after 24 months?

No. Medicare enrollment is automatic once you have received SSDI for 24 months. Social Security will send you a notice in the mail a few months before your coverage begins. You will receive your Medicare card automatically. You do not need to explore or take any action.

Can I enroll in Medicare before my birthday if I turn 65 next month?

Yes. Your enrollment window opens three months before the month you turn 65. If you turn 65 in June, you can enroll starting in March. Enrolling early is a good idea because it gives Medicare time to process your process and send your card before your coverage begins on the first day of your birth month.

What is the difference between Part A and Part B, and do I need both?

Part A covers hospital stays, skilled nursing care, and hospice. Part B covers doctor visits, outpatient care, and preventive services. Most people enroll in both, but Part B is optional if you have may have access to employer coverage. Part A is automatic for people may be able to access before 65 due to SSDI, ESRD, or ALS, and you cannot decline it.

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.