The Basic Rules for Medicare Coverage

You can enroll in Medicare when you turn 65, regardless of your health or income. You do not have to be retired. You do not have to be poor. The program covers people 65 and older, some younger people with specific disabilities, and people with end-stage renal disease or ALS at any age.

Most people become covered automatically. If you have been receiving Social Security benefits for at least four months before your 65th birthday, Medicare Part A and Part B enroll you without you doing anything. If you have not yet claimed Social Security, you will need to sign up for Medicare yourself during your enrollment window.

The enrollment window matters because missing it can cost you. If you wait past the three months before your 65th birthday, the three months of your birthday month, and the three months after, you may pay a permanent penalty on your premiums. The only exception is if you or your spouse are still working and covered by an employer health plan—in that case, you can delay without penalty.

Key Takeaways

  • You become covered at 65 if you are a U.S. citizen or permanent resident who has lived in the country for at least five years.
  • If you receive Social Security, Medicare enrolls you automatically; if you do not, you must sign up yourself during your enrollment window or face a permanent premium increase.
  • Younger people under 65 can get Medicare if they have received Social Security disability benefits for 24 months, have end-stage renal disease, or have been diagnosed with ALS.
  • Your enrollment window is seven months long: three months before your 65th birthday, your birthday month, and three months after.
  • Working past 65 and staying on your employer plan does not disqualify you, but you still need to enroll in Medicare when you leave that coverage.

Coverage for People Under 65

You can get Medicare before 65 in three situations. The first is if you have been receiving Social Security Disability Insurance (SSDI) for at least 24 months. The 24 months starts from the date your disability benefits began, not from when you applied. Once you have been on SSDI for two years, Medicare Part A and Part B cover you automatically.

The second path is if you have end-stage renal disease (ESRD)—permanent kidney failure requiring dialysis or a transplant. You can enroll in Medicare as soon as your doctor determines you need dialysis or a transplant, even if you have not yet started treatment. You have 12 months from the start of dialysis or transplant to enroll, though enrolling right away prevents gaps in coverage.

The third path is if you have been diagnosed with amyotrophic lateral sclerosis (ALS), also called Lou Gehrig's disease. You become covered when ready upon diagnosis, without waiting periods. You do not need to be on disability benefits first.

Citizenship and Residency Requirements

You must be a U.S. citizen or a permanent resident (green card holder) to get Medicare. If you are a permanent resident, you must have lived in the United States for at least five consecutive years before you turn 65. Those five years do not have to be when ready before 65—they can be any five years since you became a permanent resident.

If you are a citizen living outside the United States, you can still enroll in Medicare at 65. You will pay the same premiums and have the same coverage rules. However, Medicare typically does not pay for care you receive outside the U.S., with limited exceptions for care in Canada or Mexico if you are traveling through the U.S. to reach it.

What Happens If You Miss Your Enrollment Window

If you do not sign up for Part A or Part B during your initial enrollment window, you can still enroll later during 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 increase on your Part B premium for each full year you delayed past your initial window.

The penalty applies for as long as you have Medicare. If you delayed for three years, your premium is 30 percent higher than the standard rate. The only way to avoid this penalty is to prove you had creditable coverage—an employer plan or other health insurance that was as good as or better than Medicare—during the time you delayed.

Part A (hospital insurance) has a different penalty structure. If you delay Part A and do not have a valid reason, you pay a 10 percent increase for twice the number of years you delayed. If you delayed for two years, you pay the penalty for four years.

How Work Status Affects Your Coverage

Working past 65 does not disqualify you from Medicare. You can be employed full-time, part-time, or self-employed and still enroll. However, if you or your spouse are still working and covered by an employer health plan, you may want to delay enrolling in Part B without penalty. This is called the Special Enrollment Period, and it applies only if your employer plan has 20 or more employees.

If you use this exception and delay Part B, you must enroll within eight months of leaving your job or losing your employer coverage. If you wait longer, you will owe the permanent penalty. Part A has no such exception—if you are 65 and not working, you should enroll in Part A even if you delay Part B.

Income and Assets Do Not Affect Coverage

Medicare does not have income or asset limits. You can be a millionaire or have no savings, and you will be covered the same way at 65. Your income may affect how much you pay for premiums—higher earners pay more for Part B and Part D (prescription drug coverage)—but it does not determine whether you can enroll.

Some people with low incomes may be able to get help paying premiums and cost-sharing through Medicaid or programs like the Medicare Savings Program, but these are separate from the basic coverage decision. Your income does not prevent you from getting Medicare itself.

Enrollment Steps and Timing

If you receive Social Security, you do not need to do anything. Social Security and Medicare share information, and you will be enrolled automatically. You will receive your Medicare card in the mail about two weeks before your 65th birthday.

If you do not receive Social Security, you must enroll yourself. You can do this online through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office. You will need your birth certificate, proof of citizenship or permanent residency, and proof of residence. Enroll during your seven-month window to avoid penalties.

If you are under 65 and covered through disability or ESRD, Social Security will contact you about enrollment. If you have ALS, you will need to contact Social Security yourself to begin the enrollment process.

Frequently Asked Questions

Can I get Medicare if I am not a U.S. citizen?

You must be a U.S. citizen or permanent resident who has lived in the country for at least five consecutive years. If you are a permanent resident, those five years do not have to be recent—they can be any five years since you became a permanent resident. Undocumented immigrants and temporary visa holders do not meet the requirements.

What if I am still working at 65 and do not want to retire?

You can keep working and still enroll in Medicare. If your employer covers 20 or more employees and you are on their health plan, you can delay Part B without penalty. You must enroll within eight months of leaving that job. Part A has no such delay option, so you should enroll in it at 65 even if you delay Part B.

Do I lose Medicare if I move outside the United States?

You keep your Medicare coverage, but it does not pay for care you receive outside the U.S. in most cases. Limited exceptions exist for care in Canada or Mexico if you are traveling through the U.S. to reach it. If you move abroad permanently, you may want to review your coverage options with Medicare directly.

What if I turned 65 years ago and never signed up?

You can enroll during the General Enrollment Period (January 1 through March 31), with coverage starting July 1. However, you will owe a permanent 10 percent increase on your Part B premium for each full year you delayed. You can avoid this penalty only if you had creditable coverage through an employer or other health plan during the time you delayed.

Can I get Medicare if I have a pre-existing condition?

Yes. Medicare does not deny coverage or charge more based on health status or pre-existing conditions. At 65, you are covered regardless of your medical history. If you are under 65 and on disability, ESRD, or have ALS, your condition is the reason you become covered, not a barrier to it.