When You Become Eligible for Medicare: Age and Other Routes

You can sign up for Medicare at 65, or earlier if you have a disability or end-stage renal disease

The most common path to Medicare is turning 65. At that age, you become may be able to access for Part A (hospital insurance) and Part B (medical insurance) whether you are still working or retired. You do not have to stop working to sign up — many people keep their jobs and carry Medicare alongside employer coverage.

If you are younger than 65, you may still reach Medicare through two other routes: a disability information from Social Security, or a diagnosis of end-stage renal disease (ESRD) or ALS. Each path has different timing and different rules about when to sign up.

Key Takeaways

You become may be able to access for Medicare on the first day of the month you turn 65, and you have a three-month window before and after that month to sign up without penalty.
If you have been receiving Social Security disability benefits for 24 months, you become may be able to access for Medicare regardless of age.
A diagnosis of end-stage renal disease or ALS can make you may be able to access for Medicare before 65, usually within a few months of diagnosis or treatment start.
Signing up late — after your may be able to access window closes — can add a permanent surcharge to your Part B premium, so the timing of your enrollment matters even if you delay coverage itself.

Turning 65: The standard enrollment window

Your may be able to access for Medicare begins on the first day of the month in which you turn 65. You have a seven-month window to sign up: three months before that month, the month itself, and three months after. For example, if you turn 65 in June, your enrollment window runs from March through September.

You do not have to sign up during this window if you have health coverage through a current employer and that employer has 20 or more employees. This is called creditable coverage, and it lets you delay Part B without penalty. However, you should still sign up for Part A at 65 even if you delay Part B, because Part A has no premium for most people and the penalty for late enrollment is steeper.

If you miss your window and do not have creditable coverage, you will pay a permanent 10 percent surcharge on your Part B premium for each full year you were may be able to access but not enrolled. That surcharge stays with you for life, so the cost of waiting adds up quickly.

Disability before 65: The 24-month rule

If Social Security has determined that you have a disability, you become may be able to access for Medicare after you have been receiving Social Security Disability Insurance (SSDI) benefits for 24 months. The 24 months is measured from the month your benefits started, not from the month you applied.

Your may be able to access date is the first day of the 25th month of your SSDI. You then have the same seven-month enrollment window (three months before, the month itself, three months after) to sign up. Social Security will send you a notice when you are approaching your Medicare may be able to access date.

If you are already receiving SSDI and have not yet hit the 24-month mark, Social Security can tell you the exact month you will become may be able to access. Contact them at 1-800-772-1213 or visit your local Social Security office to confirm your date.

End-stage renal disease and ALS: when ready may be able to access

If you are diagnosed with end-stage renal disease (ESRD) — kidney failure requiring dialysis or a transplant — you become may be able to access for Medicare as soon as you start dialysis treatment or receive a kidney transplant, regardless of age. If you are on a transplant waiting list, may be able to access begins the first day of the month you are placed on the list.

If you are diagnosed with amyotrophic lateral sclerosis (ALS), you become may be able to access for Medicare the first day of the month your ALS diagnosis is made. Unlike ESRD, you do not have to wait for treatment to start.

For both conditions, you have a seven-month enrollment window starting three months before your may be able to access date. Your doctor or dialysis center can help you understand your may be able to access date and connect you with resources to sign up.

How to sign up at each stage

You can sign up for Medicare through three 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 signup is usually the fastest option if you have your Social Security number and basic health information ready.

If you are signing up based on disability or ESRD, have your Social Security award letter or medical records handy. The Social Security Administration and Medicare share information, so if you are already receiving SSDI, Medicare may contact you automatically as your 24-month mark approaches. Do not assume the contact will come — it is your responsibility to enroll during your window.

If you are still working and have employer coverage, tell Medicare about it when you sign up. This protects you from penalties if your employer coverage ends later.

What happens if you miss your enrollment window

If you pass your seven-month window without signing up and do not have creditable coverage, you enter a General Enrollment Period that runs January 1 through March 31 each year. You can sign up during this time, but your coverage will not start until July 1 of that year, and you will owe the late-enrollment penalty on Part B for the rest of your life.

The only exceptions are if you have creditable coverage (employer or union health insurance) or if you may have access to for a Special Enrollment Period. A Special Enrollment Period is a second chance window that opens if you lose creditable coverage or if certain life events occur — for example, if you move out of your plan's service area. These windows are usually 63 days long.

If you think you have a reason for a Special Enrollment Period, call 1-800-MEDICARE to ask. Do not wait — these windows close quickly.

Part A, Part B, and when each one starts

Medicare has two main parts. Part A covers hospital stays, skilled nursing facility care, hospice, and some home health services. Part B covers doctor visits, outpatient care, and medical equipment. Most people pay no premium for Part A if they or their spouse paid Medicare taxes while working. Part B has a monthly premium that changes each year.

When you turn 65 or reach may be able to access through disability or ESRD, both parts become available to you at the same time. You can sign up for both together, or you can sign up for Part A alone and delay Part B if you have creditable coverage. However, delaying Part B beyond your window will cost you in penalties, while delaying Part A has no penalty if you have creditable coverage.

Your coverage start date depends on when you sign up. If you sign up during your initial enrollment window, coverage usually starts on the first day of the month you turn 65 (or reach may be able to access). If you sign up late, coverage starts the first day of the month after you enroll.

Frequently Asked Questions

Do I have to sign up for Medicare at 65 if I am still working?

You do not have to sign up for Part B if you have health insurance through your employer and that employer has 20 or more employees. However, you should sign up for Part A at 65 because it has no premium and the late-enrollment penalty is steep. If you delay Part B, sign up within eight months of leaving your job to avoid penalties.

What if I turn 65 outside the United States?

You can still sign up for Medicare while living abroad. You have the same seven-month enrollment window. Call 1-800-MEDICARE or visit a U.S. embassy or consulate for help. Your coverage will work in the U.S. and some U.S. territories, but not in most other countries, so you may need supplemental travel insurance.

Can I sign up for Medicare before my 65th birthday?

You can sign up starting three months before the month you turn 65. For example, if you turn 65 in June, you can sign up beginning in March. Signing up early does not start your coverage early — it starts on your may be able to access date — but it ensures you are enrolled on time.

What is the difference between Medicare and Medicaid?

Medicare is a federal program based on age, disability, or ESRD diagnosis. Medicaid is a state program based on income. You can have both at the same time. They cover different services and have different rules, so do not assume one covers what the other does.

If I have SSDI, do I automatically get Medicare after 24 months?

No. You become may be able to access after 24 months of SSDI, but you must sign up yourself. Social Security may send you a notice, but enrollment is your responsibility. Sign up during your seven-month window to avoid penalties.

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.