You must be 65 or older to get Medicare, with rare exceptions for younger people with disabilities or end-stage renal disease

Medicare is a federal health insurance program run by the Centers for Medicare & Medicaid Services (CMS). The standard age to start is 65. If you turn 65, you become may be able to access for all four parts of Medicare — Part A (hospital insurance), Part B (medical insurance), Part D (prescription drug coverage), and the option to choose Part C (Medicare Advantage) instead of Parts A and B.

You do not have to wait until you turn 65 to sign up. You can enroll starting three months before the month you turn 65, during the month you turn 65, and for three months after. This window is called your Initial Enrollment Period. If you miss it, you may face a permanent penalty on your premiums, so timing matters.

There are two smaller groups who can get Medicare before 65: people under 65 who have been receiving Social Security Disability Insurance (SSDI) for 24 months, and people of any age with end-stage renal disease (ESRD) or amyotrophic lateral sclerosis (ALS). These are the only exceptions to the age rule.

Key Takeaways

  • You become may be able to access for Medicare at age 65, and you can enroll starting three months before your 65th birthday.
  • If you delay enrollment past your Initial Enrollment Period without a valid reason, you will pay a permanent 10 percent penalty on Part B premiums for as long as you have Medicare.
  • People under 65 who receive SSDI for 24 months, or who have ESRD or ALS, can get Medicare regardless of age.
  • You must be a U.S. citizen or a lawful permanent resident who has lived in the United States for at least five consecutive years to get Medicare.

How the 65-year-old rule works in practice

When you turn 65, you do not automatically get Medicare. You have to sign up. The enrollment window is seven months long: it starts three months before your birthday month and ends three months after. If your birthday is 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. You will need your Social Security number, proof of citizenship or lawful permanent residency, and information about any current health coverage you have. The process usually takes 15 to 30 minutes.

Your coverage starts on the first day of the month you turn 65, as long as you enroll during your Initial Enrollment Period. If you enroll late, your coverage may not start until the following month, which is why signing up early in your window is safer than waiting until the last month.

What happens if you miss your enrollment window

If you do not enroll in Part B during your Initial Enrollment Period and you do not have a valid reason for the delay, you will pay a permanent 10 percent surcharge on your Part B premium for as long as you have Medicare. This penalty does not go away. If you were supposed to enroll in 2024 but did not, and you enroll in 2026, you will pay the penalty starting in 2026 and continuing for life.

A valid reason to delay is called creditable coverage — this means you had health insurance through an employer or union that was at least as good as Medicare Part B. If you had group health insurance through your job or your spouse's job, you may not owe a penalty. You will need to show proof of that coverage when you enroll.

The same 10 percent penalty rule applies to Part D (prescription drug coverage). If you go 63 days or longer without Part D coverage and you do not have creditable prescription drug coverage, you will pay a permanent surcharge on your Part D premium.

Medicare for people under 65 with disabilities

If you are under 65 and receiving Social Security Disability Insurance (SSDI), 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 you turn 65. SSDI is a program for people who cannot work because of a medical condition expected to last at least 12 months or result in death.

Once you have been on SSDI for 24 months, you are automatically enrolled in Medicare Part A and Part B. You do not have to sign up yourself — Social Security will enroll you. You will receive your Medicare card in the mail about a month before your coverage starts.

If you are under 65 and have end-stage renal disease (ESRD) — kidney failure requiring dialysis or a transplant — you can get Medicare when ready, regardless of how long you have been on disability. The same is true if you have ALS (Lou Gehrig's disease). These are the only two medical conditions that override the age requirement entirely.

Citizenship and residency requirements

To get Medicare, you must be a U.S. citizen or a lawful permanent resident. If you are a lawful permanent resident, you must have lived in the United States for at least five consecutive years. This means you cannot have left the country for more than 30 days during those five years without breaking the streak.

When you explore for Medicare, you will need to prove your citizenship or permanent residency status. A U.S. birth certificate, passport, or naturalization certificate works for citizens. For permanent residents, a green card or I-551 card is the standard proof. If you do not have these documents, Social Security can help you gather what you need.

How to prepare before you turn 65

Start thinking about Medicare three to four months before your 65th birthday. Gather your Social Security number, proof of citizenship, and a list of any medications you take. If you have current health insurance through an employer, write down the plan name and your policy number — you will need this to show you had creditable coverage if you delay enrollment.

Visit Medicare.gov and use the Plan Finder tool to see what Part D (prescription drug) plans are available in your area. Prescription drug coverage changes every year, and the plans available to you depend on where you live. Comparing plans before you enroll helps you pick one that covers your medications at the lowest cost.

If you are still working at 65 and your employer has 20 or more employees, you may not need to enroll in Part B right away. You can delay Part B without penalty as long as you enroll within eight months of leaving your job or losing your employer coverage. This is called the Special Enrollment Period, and it is one of the few valid reasons to enroll late without a penalty.

What to do if you turned 65 and did not enroll

If you are past your Initial Enrollment Period and did not sign up, you can still enroll, but you may owe a penalty. The next chance to enroll without a penalty is during the General Enrollment Period, which runs from January 1 through March 31 each year. If you enroll during this window, your coverage starts July 1 of that year.

Before you enroll late, check whether you have a valid reason to delay. If you had creditable coverage through an employer or union, or if you were still working and covered under your employer's plan, you may not owe a penalty. Bring proof of that coverage when you enroll — a letter from your employer's benefits office or a copy of your insurance card works.

If you do not have a valid reason and you enroll late, the 10 percent penalty will be added to your Part B premium. Calculate how much this will cost you over time. If you are 67 and enroll for the first time, you might pay the penalty for 20 or 30 years, so it is worth understanding the full cost before you commit.

Frequently Asked Questions

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

No, unless you have SSDI, ESRD, or ALS. If you are still working at 65, you can delay enrolling in Part B without penalty as long as your employer has 20 or more employees and you enroll within eight months of leaving the job or losing coverage. You should still enroll in Part A at 65, even if you are working.

What if I was not a U.S. citizen when I turned 65 but became one later?

You can enroll in Medicare once you become a U.S. citizen or lawful permanent resident. Your enrollment window starts three months before the month you become a citizen or permanent resident. If you miss that window, you can enroll during the General Enrollment Period (January 1 through March 31) without a penalty, as long as you have a valid reason for the delay.

Do I have to enroll in all four parts of Medicare at 65?

No. You must enroll in Part A (hospital insurance) at 65 to avoid a penalty. Part B (medical insurance) and Part D (prescription drug) have their own enrollment periods and penalties. Part C (Medicare Advantage) is optional and replaces Parts A and B if you choose it. You can pick and choose based on your health and coverage needs.

What happens to my employer health insurance when I turn 65?

Your employer insurance does not automatically end when you turn 65. You can keep it if your employer offers it. However, Medicare becomes your primary payer once you enroll, and your employer plan becomes secondary. If you have both, Medicare pays first, then your employer plan covers what Medicare does not. Check with your employer's benefits office about what happens to your coverage at 65.

Can I delay Medicare if I am still healthy and do not think I need it?

You can delay Part B if you have creditable coverage through an employer with 20 or more employees, but you should still enroll in Part A at 65 to avoid a penalty. Part A has no monthly premium if you or your spouse paid Medicare taxes for at least 10 years, so there is no financial reason to delay it. Delaying Part B or Part D without a valid reason will cost you a permanent penalty.