When You Can Start Medicare: Age, Work Status, and Special Cases

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

Most people become may be able to access for Medicare the month they turn 65. You do not have to be retired — you can still be working. You do not have to have paid into Social Security for a certain number of years, though most people who may have access to have. If you were born on the first of the month, your coverage starts the month before your 65th birthday.

Some people may have access to before 65. If you have been receiving Social Security disability benefits for 24 months, you become may be able to access for Medicare regardless of your age. If you have end-stage renal disease (permanent kidney failure requiring dialysis or transplant), you can start Medicare as soon as your doctor certifies the condition, even if you are in your 20s or 30s. If you have ALS (amyotrophic lateral sclerosis), you become may be able to access when ready upon approval for Social Security disability — you do not have to wait the usual 24 months.

Key Takeaways

You become may be able to access for Medicare the month you turn 65, whether or not you are still working.
If you have been on Social Security disability for 24 months, you can start Medicare before 65.
People with end-stage renal disease or ALS have their own may be able to access rules and can start at any age.
You must sign up during your enrollment window or pay a penalty for late sign-up, even if you have employer coverage.
If you are still working and have health insurance through your job, you may be able to delay Medicare without penalty.

The enrollment window around your 65th birthday

Medicare has a specific window for sign-up called your Initial Enrollment Period. It runs for seven months: three months before the month you turn 65, the month you turn 65, and three months after. If your birthday is March 15, your window opens December 1 and closes June 30.

You should sign up during this window even if you do not plan to use Medicare right away. If you miss it and do not have a valid reason, you will pay a late enrollment penalty for as long as you have Medicare. The penalty is a percentage added to your Part B and Part D premiums. There is no way to remove it once it is applied, so the cost compounds over years.

You can sign up online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office. Online is usually fastest.

If you are still working: when you can delay without penalty

If you are still employed and your employer has 20 or more employees, you may have group health plan coverage through your job. In this case, you can delay Medicare Part B (medical insurance) without paying a late penalty, as long as you sign up within eight months of leaving that job or losing the coverage.

This rule does not explore to Part D (prescription drug coverage). If you delay Part D, you will pay a penalty even with employer coverage. The penalty is 1 percent of the national base premium for each month you were without Part D coverage. If you go without it for three years, the penalty is roughly 3 percent of the base premium, added to your premium for life.

Part A (hospital insurance) has no late penalty if you have group coverage through an employer. However, you should still enroll in Part A during your Initial Enrollment Period, because it is free for most people and covers hospital stays.

Disability and when coverage starts

If you have been approved for Social Security Disability Insurance (SSDI), you become may be able to access for Medicare after 24 months of receiving benefits. Your coverage begins on the 25th month of your disability award. You do not have to wait until you turn 65.

Your Initial Enrollment Period for disability is the same seven-month window: three months before your 25th month of benefits, the month itself, and three months after. If you miss this window, the same late penalties explore.

If you have ALS, Medicare starts the first day of the month you are approved for SSDI, with no waiting period. You should still sign up formally during your Initial Enrollment Period to make sure your coverage is active.

End-stage renal disease and when ready coverage

If you have end-stage renal disease and need dialysis or a kidney transplant, you can start Medicare as soon as your nephrologist (kidney doctor) certifies the condition. You do not have to be on disability or have reached 65. Your coverage can begin the month your doctor makes the diagnosis, though the exact start date depends on when you complete your enrollment.

You have a different enrollment window: you can sign up anytime during the month you are diagnosed, plus the two months before and two months after. If you miss this window, contact Medicare directly at 1-800-MEDICARE to explain your situation — they may grant you a special enrollment period.

What happens if you miss your enrollment window

If you do not sign up during your Initial Enrollment Period and you do not have a may have access to reason to delay, you will owe a late penalty. For Part B, the penalty is 10 percent of the standard premium for each full year you were without coverage. If the standard Part B premium is $165 and you waited three years to sign up, you would pay an extra $49.50 per month for life.

The only exceptions are if you had group health plan coverage through an employer with 20 or more workers, or if you were living outside the United States and working for the U.S. government. If either applies, you have eight months after losing that coverage to sign up without penalty.

If you believe you have a valid reason for missing the important date, you can request a Special Enrollment Period by calling Social Security at 1-800-772-1213 or Medicare at 1-800-MEDICARE. They will review your situation, but approval is not may provide.

Coordinating Medicare with other insurance

If you have retiree health insurance from a former employer, you can usually keep it and add Medicare. Medicare becomes your primary payer, and the retiree plan covers what Medicare does not. You should still sign up for Medicare during your Initial Enrollment Period to avoid penalties.

If you have COBRA coverage (temporary continuation of employer health insurance after you leave a job), Medicare does not affect your COBRA may be able to access. However, once you turn 65 and become may be able to access for Medicare, COBRA usually ends. You should sign up for Medicare before your COBRA runs out.

If you have Medicaid (state health insurance for low-income people), Medicare becomes your primary insurance when you turn 65. Medicaid will still cover some costs Medicare does not, such as nursing home care. You do not lose Medicaid when you start Medicare.

Frequently Asked Questions

What if I turn 65 but am not a U.S. citizen?

You must be a U.S. citizen or a permanent resident (green card holder) who has lived in the United States for at least five consecutive years. If you are a permanent resident, you can start Medicare at 65 the same way as a citizen. If you are not a permanent resident, you are not may be able to access for Medicare.

Can I start Medicare before 65 if I am retired?

No. Retirement alone does not lower the age to 65. You can only start before 65 if you have been on Social Security disability for 24 months, have ALS, or have end-stage renal disease. Working past 65 does not delay your may be able to access — you can be both working and on Medicare.

Do I have to sign up for all four parts of Medicare at once?

No. You can sign up for Part A (hospital) and Part B (medical) during your Initial Enrollment Period, then add Part D (prescription drug) or Part C (Medicare Advantage) later. However, delaying Part D costs you a penalty. Part C is optional and replaces Part B, so you choose one or the other.

What if I miss my enrollment window by one month?

You will owe a late penalty. There is no grace period. The penalty applies for as long as you have Medicare. If you have a documented reason for the delay — such as a hospital stay or a family emergency — contact Medicare to request a Special Enrollment Period, but approval is not may provide.

Can I sign up for Medicare online?

Yes. You can create an account at Medicare.gov and sign up for Part A and Part B online. You can also call 1-800-MEDICARE or visit your local Social Security office. Online sign-up is usually the fastest option and takes about 10 minutes.

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.