When Medicare Coverage Starts: Age, Disability, and Other Pathways

Medicare starts at 65 for most people, but you can enroll earlier if you have a disability or end-stage renal disease

You become may be able to access for Medicare at age 65 if you are a U.S. citizen or permanent resident who has lived in the country for at least five years. You do not have to be retired—Medicare may be able to access is based on age alone, not work status. If you are already receiving Social Security benefits when you turn 65, you are enrolled automatically. If you are not yet collecting Social Security, you must sign up for Medicare yourself during your enrollment window, or you may face a penalty on your premiums.

You can enroll before 65 if you have been receiving Social Security Disability Insurance (SSDI) for 24 months, or if you have end-stage renal disease (permanent kidney failure requiring dialysis or transplant) or ALS (amyotrophic lateral sclerosis). These pathways exist because these conditions create healthcare costs that Medicare is designed to cover, regardless of age.

Key Takeaways

You are may be able to access for Medicare at 65 if you are a U.S. citizen or permanent resident who has lived here for five years; enrollment is automatic if you are already on Social Security.
You can enroll before 65 if you have received SSDI for 24 months, have end-stage renal disease, or have ALS.
Your enrollment window is seven months long: three months before the month you turn 65, the month itself, and three months after—missing it can cost you permanently higher premiums.
If you are still working at 65 and have employer health insurance, you may be able to delay enrollment without penalty, but you must notify Medicare of your work status.
Medicare Part A (hospital insurance) is free for most people; Part B (medical insurance) has a monthly premium that increases if you delay enrollment past 65.

The seven-month enrollment window around age 65

Your Initial Enrollment Period is seven months long: it starts three months before the month you turn 65, includes the month of your birthday, and runs three months after. For example, if you turn 65 in June, your window opens in March and closes in September. During this window, you can enroll in Medicare Part A and Part B without waiting or paying a penalty.

If you miss this window, you can still enroll, but you will pay a permanent penalty on your Part B premium—10 percent more for each full year you delayed past 65. This penalty stays with you for life, even if you enroll years later. The only exception is if you were covered by an employer health plan while working; in that case, you have eight months after your employment or coverage ends to enroll without penalty.

Disability and the 24-month SSDI rule

If you receive Social Security Disability Insurance, you become may be able to access for Medicare after you have been on SSDI for 24 months. You do not have to wait until 65. Medicare enrollment happens automatically once the 24 months are up; you will receive a notice in the mail about two months before your coverage begins.

This rule applies whether you became disabled at 30 or 60. The 24-month clock starts from the month you first received a disability benefit check, not from the month you applied. If you are unsure when your 24 months will be complete, you can call Social Security at 1-800-772-1213 to confirm your may be able to access date.

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

You are may be able to access for Medicare when ready upon diagnosis of end-stage renal disease (ESRD)—permanent kidney failure that requires dialysis or a transplant. You do not have to wait 24 months or reach 65. Your doctor or the dialysis center will help you enroll; Medicare coverage typically begins the first day of the month in which you start dialysis or receive a transplant.

ALS (Lou Gehrig's disease) also qualifies you for when ready Medicare may be able to access at any age. You must explore through Social Security, and you will need medical documentation of your ALS diagnosis. Once approved, your coverage begins the month you are deemed may be able to access, which is usually the month you applied or shortly after.

Automatic enrollment if you are on Social Security

If you are already receiving Social Security retirement or disability benefits when you turn 65, you do not need to do anything—Medicare Part A and Part B are enrolled automatically about three months before your 65th birthday. You will receive a Medicare card in the mail and information about your coverage. Part A (hospital insurance) is free; Part B (medical insurance) will be deducted from your Social Security check unless you decline it in writing.

If you are not yet on Social Security when you turn 65, you must enroll in Medicare yourself. You can do this online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office. Do this during your seven-month enrollment window to avoid penalties.

Still working at 65: when you can delay enrollment

If you are still working and covered by an employer health plan at 65, you may be able to delay Medicare Part B enrollment without penalty. This is called the Special Enrollment Period for active workers. You must have creditable coverage (health insurance through your employer or your spouse's employer), and you must notify Medicare that you are still working.

When you finally leave your job or lose your employer coverage, you have eight months to enroll in Medicare Part B without paying a late penalty. You must enroll during this window; if you wait longer, the 10 percent monthly penalty applies. Part A (hospital insurance) does not have a late penalty, but you should still enroll when your employer coverage ends to avoid gaps in coverage.

What happens after you enroll

Once you are enrolled, your Medicare coverage begins on the first day of the month you turn 65 (or the month you become may be able to access through disability or ESRD). You will receive a Medicare card showing your name, Medicare number, and the date your coverage starts. Keep this card with you when you see doctors or go to the hospital.

Medicare Part A covers hospital stays, skilled nursing care, hospice, and some home health services. Part B covers doctor visits, outpatient care, and medical equipment. Neither covers dental, vision, or hearing care. Many people add Part D (prescription drug coverage) and either Medigap (supplemental insurance) or Medicare Advantage (an alternative plan) to fill gaps. You have a window to enroll in these without penalty; if you miss it, you may pay more later.

Frequently Asked Questions

What if I turn 65 but am not yet on Social Security?

You must enroll in Medicare yourself during your seven-month enrollment window. You can sign up online at Medicare.gov, call 1-800-MEDICARE, or visit a Social Security office. If you do not enroll by the end of your window, you will pay a permanent 10 percent penalty on your Part B premium.

Can I delay Medicare if I have employer health insurance?

Yes, if your employer plan is creditable coverage (most are). You must notify Medicare that you are still working. When you leave your job, you have eight months to enroll in Part B without penalty. Part A has no late penalty, but you should still enroll to avoid gaps in hospital coverage.

Do I have to take Part B if I am automatically enrolled at 65?

If you are automatically enrolled because you are on Social Security, Part B is enrolled unless you decline it in writing before it starts. You can decline Part B if you have employer coverage, but you must tell Medicare in writing. If you decline and later want to enroll, you may face a late penalty.

What if I have SSDI but have not been on it for 24 months yet?

You are not yet may be able to access for Medicare. Once you reach 24 months on SSDI, Social Security will enroll you automatically. You will receive a notice about two months before your coverage begins. You can call Social Security at 1-800-772-1213 to confirm your exact may be able to access date.

Is there a penalty if I delay Part A enrollment?

No. Part A (hospital insurance) has no late penalty. However, you should still enroll when you become may be able to access to avoid gaps in coverage. Part B does have a late penalty if you delay past your enrollment window without creditable coverage.

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.