The Basic Age and Citizenship Rules

You can enroll in Medicare when you turn 65, regardless of your income or health history. You must be a U.S. citizen or a lawful permanent resident who has lived in the country for at least five consecutive years. If you are already receiving Social Security benefits when you turn 65, Medicare enrollment happens automatically — you do not need to do anything. If you are not yet collecting Social Security, you will need to sign up for Medicare yourself during your enrollment window.

The enrollment window is a seven-month period that starts three months before the month you turn 65 and ends three months after. For example, if you turn 65 in June, your window runs from March through September. Signing up during this window means your coverage can start the month you turn 65. If you miss this window, you may face a permanent penalty on your premiums, so timing matters.

Key Takeaways

  • You become may be able to access for Medicare at age 65 if you are a U.S. citizen or lawful permanent resident who has lived in the country for at least five consecutive years.
  • If you are already collecting Social Security when you turn 65, Medicare enrollment is automatic and requires no action on your part.
  • If you are not yet receiving Social Security, you must sign up for Medicare yourself during your seven-month enrollment window centered on your 65th birthday.
  • Missing your enrollment window can result in a permanent increase to your premiums, so it is important to enroll on time even if you do not plan to use Medicare right away.
  • You may be able to enroll before 65 if you have been receiving Social Security Disability Insurance (SSDI) for at least 24 months or if you have end-stage renal disease or ALS.

Enrolling Before Age 65

In some cases, you can join Medicare before you turn 65. If you have been receiving Social Security Disability Insurance (SSDI) for at least 24 months, you become may be able to access for Medicare automatically at the end of that 24-month period. You do not need to wait until 65. Similarly, if you have end-stage renal disease (permanent kidney failure requiring dialysis or transplant) or ALS (amyotrophic lateral sclerosis), you can enroll in Medicare regardless of age.

If you fall into one of these categories, Social Security will contact you about your Medicare enrollment. Read the notice carefully and follow the instructions, because your coverage start date depends on when you complete the enrollment process. If you have questions about your specific situation, you can call Social Security at 1-800-772-1213 to confirm your may be able to access date.

Working Past 65 and Delayed Enrollment

If you are still working at 65 and your employer has 20 or more employees, you may be able to delay Medicare enrollment without penalty. This is called creditable coverage. Your employer's health plan is usually considered creditable, meaning you can stay on that plan and enroll in Medicare later without the late-enrollment penalty. However, you must have actual coverage through your employer — straightforward being employed is not enough.

If you choose to delay, you must enroll in Medicare within eight months after your employment ends or your employer coverage stops, whichever comes first. If you miss that important date, you will owe a permanent penalty. To be safe, contact Medicare or Social Security before you leave your job to confirm your enrollment important date and avoid surprises.

Part A and Part B: What You Need to Know About Each

Part A covers hospital stays, skilled nursing facility care, hospice, and some home health services. Most people do not pay a monthly premium for Part A if they or their spouse paid Medicare taxes while working for at least 10 years (40 quarters). If you do not meet that requirement, you can still purchase Part A, but the monthly cost varies based on how many quarters of Medicare taxes you paid.

Part B covers doctor visits, outpatient care, medical equipment, and preventive services. Part B requires a monthly premium, which is based on your income. Higher earners pay more. You must actively choose to enroll in Part B during your enrollment window — it does not happen automatically unless you are already receiving Social Security. If you delay Part B without creditable coverage from an employer plan, you will owe a permanent penalty.

Income and Resources Do Not Affect Medicare Enrollment

Medicare enrollment is not based on how much money you have or earn. Unlike some other programs, there is no income limit that disqualifies you, and there is no asset test. You can be wealthy and still enroll in Medicare at 65. You can also be low-income and still enroll. Your financial situation affects which programs you might also be able to use — such as Medicaid or Extra Help for prescription drug costs — but it does not change your Medicare may be able to access itself.

This is one of the key differences between Medicare and means-tested programs. Medicare is based on age, disability status, or specific medical conditions, not on need. If you turn 65 and meet the citizenship and residency requirements, you can enroll, period.

Citizenship and Residency Requirements

You must be a U.S. citizen or a lawful permanent resident. Lawful permanent residents are people who have been granted the right to live and work in the United States permanently — often called "green card holders." If you are a lawful permanent resident, you must have lived in the United States for at least five consecutive years when ready before you turn 65 to be may be able to access for Medicare.

If you are a citizen, there is no residency requirement — you can have lived outside the U.S. and still enroll at 65. If you are unsure whether you meet these requirements, bring your citizenship or permanent residency documents when you visit your local Social Security office, or call 1-800-772-1213 to ask.

Special Situations: Spouses and Government Employees

If you are married, your spouse can enroll in Medicare at 65 even if you have not yet turned 65 yourself. Your spouse's enrollment is independent — it does not depend on your age or enrollment status. Each person enrolls during their own seven-month window centered on their 65th birthday.

Some government employees, particularly those hired before 1984, may not have paid Medicare taxes and may not be may be able to access for premium-free Part A. If you worked for a federal, state, or local government and are unsure about your Part A status, contact Social Security before you turn 65. They can tell you whether you will owe a premium and how much it will be.

Frequently Asked Questions

What happens if I miss my enrollment window?

If you miss your seven-month enrollment window and do not have creditable coverage from an employer plan, you will owe a permanent penalty on your Part B and Part D premiums. The penalty is 10 percent of the Part B premium for each full 12 months you were may be able to access but not enrolled. This penalty stays with you for life, so it is important to enroll on time.

Can I enroll in Medicare if I am still working?

Yes. You can enroll in Medicare at 65 even if you are still working. If your employer has 20 or more employees and you have coverage through their health plan, you may be able to delay Part B enrollment without penalty. Check with your employer's benefits office to confirm whether your plan is considered creditable coverage.

Do I have to enroll in Part B if I have employer coverage?

No, you can delay Part B if you have creditable coverage through an employer with 20 or more employees. However, you must enroll within eight months after your employment ends or your employer coverage stops. If you wait longer, you will owe a permanent penalty.

What if I am not a U.S. citizen?

You can enroll in Medicare if you are a lawful permanent resident and have lived in the United States for at least five consecutive years when ready before you turn 65. If you are not a citizen or permanent resident, you are not may be able to access for Medicare. Contact Social Security to discuss your specific immigration status.

Does my income affect whether I can enroll in Medicare?

No. Medicare enrollment is not based on income. You can enroll at 65 whether you earn nothing or a high income. Your income may affect your Part B premium amount — higher earners pay more — but it does not determine whether you are may be able to access to enroll.