The Basic Age Rule: 65 and Older

You become may be able to access for Medicare the month you turn 65, regardless of whether you are still working. If your birthday is the 15th or later in the month, your coverage starts the first day of the following month. If your birthday is the 1st through the 14th, coverage starts the first day of that month.

You do not have to retire to sign up, and you do not have to stop working. Medicare runs alongside employer coverage or any other insurance you have. The key date is your 65th birthday, not your employment status or income level.

Key Takeaways

  • You become may be able to access for Medicare at age 65, and enrollment typically happens automatically if you are already receiving Social Security.
  • If you are still working and have employer health insurance, you may be able to delay Medicare Part B without penalty, but you must enroll in Part A.
  • You can become may be able to access before 65 if you have received Social Security disability benefits for 24 months, have end-stage renal disease, or have ALS (amyotrophic lateral sclerosis).
  • Your initial enrollment window is seven months long — three months before the month you turn 65, the month itself, and three months after — and missing it can cost you permanently higher premiums.
  • If you are not yet receiving Social Security, you must contact Social Security or Medicare directly to enroll; it does not happen automatically.

may be able to access Before Age 65

Three groups of people under 65 can become may be able to access for Medicare. The first is anyone who has received Social Security Disability Insurance (SSDI) for 24 consecutive months. The 24-month waiting period starts from the month your disability benefits begin, not from the month you applied. Once you have received SSDI for 24 months, Medicare starts automatically the 25th month.

The second group is people with end-stage renal disease (ESRD) — permanent kidney failure requiring dialysis or a transplant. You become may be able to access when ready upon diagnosis, without any waiting period. The third group is people with ALS (amyotrophic lateral sclerosis), also called Lou Gehrig's disease. ALS patients become may be able to access when ready, with no waiting period.

If you fall into one of these three categories, Medicare may be able to access is not based on age. You will need to contact Social Security or Medicare directly to enroll, because the process does not happen automatically the way it does at 65.

How Social Security Affects Your Enrollment

If you are already receiving Social Security retirement or disability benefits when you turn 65, Medicare Part A and Part B are enrolled automatically. You will receive your Medicare card in the mail about three months before your 65th birthday. You do not need to do anything — the enrollment happens on its own.

If you are not yet receiving Social Security, you must contact Medicare or Social Security yourself to enroll. This is the most common reason people miss their enrollment window. Social Security does not know you want Medicare unless you tell them. You can enroll online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.

The Initial Enrollment Window and Penalty Rules

Your Initial Enrollment Period (IEP) is seven months long: three months before the month you turn 65, the month of your birthday, and three months after. If your birthday is March 15, your window runs from December through June. If you enroll during this seven-month window, your coverage starts on the first day of your birthday month (or the month after, depending on your birthday date).

If you miss this window, you can still enroll later, but you will pay a permanent penalty on your Part B premium for as long as you have Medicare. The penalty is 10 percent of the standard Part B premium for each full year you delayed past your IEP. If you delayed for three years, you pay 30 percent more every month for life. There is no way to remove this penalty once it is applied.

The only exception is if you had creditable coverage — employer health insurance or union coverage — during the time you delayed. If your employer plan was as good as or better than Medicare Part B, you can enroll later without penalty. You will need to provide proof of that coverage when you enroll.

Working Past 65 and Employer Coverage

If you are still working at 65 and your employer has 20 or more employees, you can delay Medicare Part B without penalty. You must still enroll in Part A (hospital insurance), but you can wait on Part B (medical insurance) as long as you have employer coverage. Once you leave that job or lose the coverage, you have eight months to enroll in Part B without penalty.

This rule applies only to your own employer coverage — not to a spouse's plan. If you are covered under your spouse's employer insurance, you still cannot delay Part B without penalty. You must enroll in Part B when you turn 65, even though you have other coverage.

If your employer has fewer than 20 employees, Medicare becomes your primary insurance at 65, and you should enroll in both Part A and Part B. Your employer plan will be secondary.

Special Enrollment Periods for Life Changes

If you miss your Initial Enrollment Period but experience certain life changes, you may get a Special Enrollment Period (SEP) that lets you enroll without penalty. The most common trigger is loss of employer coverage — if you leave your job, are laid off, or lose coverage, you have eight months to enroll in Part B without penalty.

Other may have access to events include moving out of your Medicare Advantage plan's service area, losing Medicaid coverage, or having your employer plan end. You must enroll within the specific window tied to each event — usually 60 days to eight months depending on what happened. You will need to provide documentation of the event when you enroll.

What Happens If You Do Not Enroll

If you do not enroll in Part A by the end of your Initial Enrollment Period, you can still enroll later, but you may owe a penalty on your Part A premium as well. The Part A penalty is 10 percent of the standard premium for twice the number of years you delayed. If you delayed for two years, you pay 40 percent more on Part A premiums.

You can also face a gap in coverage. If you turn 65, do not enroll, and do not have other may have access to coverage, you will have no hospital insurance. Any hospital stay will be your responsibility to pay for in full. This is why enrollment during your Initial Enrollment Period matters, even if you feel healthy.

Frequently Asked Questions

What if I turn 65 but am not ready to retire?

You can enroll in Medicare and keep working. If your employer has 20 or more employees, you can delay Part B while keeping your job, but you must enroll in Part A. If your employer has fewer than 20 employees, Medicare becomes primary and you should enroll in both parts.

Do I have to enroll in Medicare if I have good employer coverage?

You must enroll in Part A at 65. You can delay Part B only if your employer has 20 or more employees and you are actively working there. Once you leave that job, you have eight months to enroll in Part B without penalty.

Can I change my mind if I enrolled too early?

Yes, but only once. You can request to withdraw your enrollment within 12 months of when it started. After that, you are locked in until the next Annual Enrollment Period in the fall, and you may face penalties if you made a mistake.

What if I was on disability but now I am working again at 64?

You stay on Medicare. Once you have been on SSDI for 24 months and become may be able to access, that may be able to access continues even if you return to work. You do not lose Medicare when your disability benefits end.

How do I know if my employer coverage counts as creditable?

Ask your employer's benefits department directly whether your plan meets Medicare's creditable coverage standard. You will need written proof of this when you enroll in Medicare later. Do not assume — get it in writing before you leave the job.