When You Can Sign Up for Medicare: Age and Timing Rules

Medicare starts at 65 for most people

You become may be able to access for Medicare at age 65, regardless of whether you are still working. This is the standard age set by federal law. You do not have to retire to sign up, and you do not have to be retired to use it. If you are already receiving Social Security benefits when you turn 65, Medicare enrollment happens automatically. If you are not yet collecting Social Security, you will need to sign up for Medicare yourself.

The month you turn 65 is when your coverage can begin, but the exact start date depends on when you submit your enrollment information. Medicare coverage typically begins on the first day of the month in which you turn 65, or the first day of the following month if you enroll after your birthday month has passed.

Key Takeaways

You are may be able to access to sign up for Medicare the month you turn 65, and coverage can start as early as the first day of that month.
If you are receiving Social Security when you turn 65, you are enrolled in Medicare automatically and do not need to take action.
If you do not sign up during your initial enrollment period, you may face permanent penalties on your premiums, even if you sign up later.
Some people under 65 can sign up for Medicare if they receive Social Security Disability Insurance (SSDI) for at least 24 months or have end-stage renal disease or ALS.
Your initial enrollment period lasts seven months: three months before the month you turn 65, the month itself, and three months after.

Your initial enrollment period: the seven-month window

You have a specific window to sign up for Medicare without facing late penalties. This initial enrollment period runs for seven months total: the three months before you turn 65, the month you turn 65, and the three months after. For example, if you turn 65 in June, your enrollment period runs from March through September.

It is important to sign up during this window, even if you do not plan to use Medicare right away. If you miss this period and do not have other health coverage that counts as "creditable coverage" (coverage that is at least as good as Medicare), you will owe a permanent penalty when you finally do sign up. The penalty is calculated as a percentage of the standard premium and stays with you for life.

You can sign up online through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office. The Social Security Administration handles Medicare enrollment for most people.

Automatic enrollment if you receive Social Security

If you are already collecting Social Security retirement, spousal, or survivor benefits when you turn 65, the Social Security Administration automatically enrolls you in Medicare Part A and Part B. You do not have to do anything. About three months before your 65th birthday, you will receive a notice in the mail explaining your coverage.

Even though enrollment is automatic, you should still review the notice carefully. Check that your name, address, and other details are correct. If you do not want Part B coverage for some reason (for instance, because you have employer coverage and want to delay), you can decline it in writing, though this is rare and usually not recommended.

People under 65 who can sign up for Medicare

You do not have to wait until 65 if you fall into one of three categories. If you have received Social Security Disability Insurance (SSDI) for at least 24 consecutive months, you become may be able to access for Medicare at that point, regardless of your age. If you have end-stage renal disease (permanent kidney failure requiring dialysis or transplant), you can sign up when ready. If you have ALS (amyotrophic lateral sclerosis, also called Lou Gehrig's disease), you do not have to wait 24 months — you are may be able to access right away.

To sign up under these circumstances, contact Social Security directly at 1-800-772-1213 or visit your local Social Security office. You will need documentation of your condition or proof of your SSDI award. The process is the same as for people turning 65, but the timing is different.

What happens if you miss your enrollment period

If you do not sign up during your initial seven-month window and you do not have creditable coverage, you will face a late enrollment penalty when you do sign up. For Part B, the penalty is 10 percent of the standard premium for each full 12-month period you were may be able to access but not enrolled. This penalty is permanent — it does not go away after a certain time.

The same rule applies to Part D (prescription drug coverage). If you go 63 days or more without creditable drug coverage, you will owe a penalty when you join a Part D plan. The penalty is calculated based on the national average premium and the length of the gap.

There are limited exceptions. If you have creditable coverage through an employer or union, you can delay enrollment without penalty as long as that coverage continues. Once that coverage ends, you have a special enrollment period of up to 63 days to sign up without penalty. You will need to provide proof of your previous coverage.

Timing your coverage to match your birthday

Your Medicare coverage start date depends on when you enroll. If you sign up before the month you turn 65, your coverage begins the first day of the month you turn 65. If you sign up during the month you turn 65, coverage starts the first day of the following month. If you sign up after the month you turn 65, coverage begins the first day of the month after you enroll.

This timing matters if you are coordinating Medicare with other coverage. If you have employer health insurance and plan to drop it when Medicare starts, make sure your Medicare coverage date lines up so you do not have a gap. Talk to your employer's benefits office about the exact date your group coverage ends.

Frequently Asked Questions

Do I have to be retired to sign up for Medicare at 65?

No. You can sign up for Medicare at 65 whether you are still working or not. If you are working and have employer coverage, you can delay Part B enrollment without penalty as long as your employer has 20 or more employees and you are enrolled in their plan.

What if I turn 65 but do not want Medicare yet?

You can decline Part B during your initial enrollment period if you have creditable coverage through an employer or union. You must sign up for Part A (hospital insurance) unless you are still working and covered by an employer plan. When your employer coverage ends, you have a special enrollment period to sign up for Part B without penalty.

Can my spouse sign up for Medicare at a different age than me?

Yes. Each person becomes may be able to access at their own age 65 (or earlier if they may have access to under disability or other rules). Your spouse's enrollment does not affect yours, and you can sign up at different times.

What is creditable coverage and why does it matter?

Creditable coverage is health insurance that is at least as good as Medicare. It includes employer plans, union plans, COBRA, and some individual plans. If you have creditable coverage when you turn 65, you can delay Medicare Part B and Part D enrollment without facing late penalties, as long as you sign up within 63 days of losing that coverage.

If I am on disability and turn 65, what changes?

When you turn 65, your SSDI benefits automatically convert to Social Security retirement benefits at the same amount. Your Medicare coverage continues without interruption. There is no gap or change to your health insurance.

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.