When You Can Start Medicare: Age Requirements and Your Options

The standard age to start Medicare is 65

You become may be able to access for Medicare the month you turn 65, regardless of whether you are still working. Most people sign up during the three months before their 65th birthday — the three months after, or the month they turn 65 itself. This window is called your Initial Enrollment Period.

If you miss this window, you can still sign up later, but you may face a permanent penalty on your premiums. The penalty grows the longer you wait, so signing up on time matters even if you do not plan to use Medicare right away.

Key Takeaways

You can start Medicare at 65, and you have a seven-month window centered on your birthday to sign up without penalty.
If you are still working and have health coverage through your job, you may be able to delay Medicare without penalty under certain conditions.
You can sign up for Medicare online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
Missing your Initial Enrollment Period results in a permanent increase to your Part B and Part D premiums that lasts as long as you have Medicare.
Some people under 65 — those with End-Stage Renal Disease, ALS, or permanent disability — can start Medicare earlier.

What happens if you are still working at 65

Working past 65 does not stop you from getting Medicare. You become may be able to access at 65 whether you are employed or retired. However, if your employer has 20 or more employees and you are covered under your employer's health plan, you may be able to delay Medicare Part B without penalty.

This is called the Special Enrollment Period for people with group health coverage. You must have actual coverage through your current employer — coverage through a spouse's employer counts, but coverage you kept after leaving a job (COBRA) does not. If you may have access to, you can wait to sign up for Part B until you or your spouse stops working or loses the employer coverage, whichever comes first.

Part A (hospital insurance) has no penalty for delay if you have employer coverage, so many people sign up for Part A at 65 and delay Part B. You will need to sign up for Part B within eight months of losing your employer coverage to avoid the permanent penalty.

Signing up during your Initial Enrollment Period

Your Initial Enrollment Period runs for seven months: the three months before the month you turn 65, the month you turn 65, and the three months after. For example, if you turn 65 in June, your window opens in March and closes in September.

You can sign up online at Medicare.gov without visiting an office. You will need your Social Security number, proof of citizenship or legal residency, and information about any current health coverage. You can also call 1-800-MEDICARE (1-800-633-4227) to sign up by phone, or visit your local Social Security office in person.

If you sign up during your Initial Enrollment Period, your coverage usually starts the first day of the month you turn 65. If you sign up after that window closes, your coverage start date depends on when you sign up, and you will face premium penalties.

What the penalty looks like if you miss the important date

If you do not sign up for Part B during your Initial Enrollment Period and do not have a may have access to reason for the delay, Medicare adds a permanent 10 percent penalty to your Part B premium for each full 12-month period you were not signed up. This penalty stays with you for life.

For example, if you turn 65 in 2024 and do not sign up until 2026, you owe two years of penalties — 20 percent extra on your Part B premium forever. The same rule applies to Part D (prescription drug coverage): missing the important date adds a 1 percent penalty per month to your premium, also permanent.

The only way to avoid this penalty is to have had creditable coverage — health insurance that is at least as good as Medicare Part B or Part D — during the time you were not signed up. Employer coverage, COBRA, and some other plans count. Coverage through Medicaid or the Affordable Care Act marketplace may or may not count, depending on the plan.

Starting Medicare before 65

Most people cannot start Medicare until 65, but three groups can begin earlier. If you have been receiving Social Security Disability Insurance (SSDI) for 24 months, you become may be able to access for Medicare at any age. If you have End-Stage Renal Disease (permanent kidney failure requiring dialysis or transplant), you can start Medicare regardless of age. If you have ALS (amyotrophic lateral sclerosis, also called Lou Gehrig's disease), you can start Medicare when ready upon diagnosis.

If you fall into one of these groups, you will receive a notice from Social Security or Medicare explaining your may be able to access and enrollment window. The enrollment rules are the same as for people turning 65 — you have a seven-month Initial Enrollment Period, and missing it results in permanent penalties.

Coordinating Medicare with other coverage

If you have health coverage from your current employer, a spouse's employer, COBRA, the Affordable Care Act marketplace, or Medicaid when you turn 65, you need to understand how Medicare coordinates with that coverage. In most cases, Medicare becomes your primary insurance at 65, meaning it pays first. Your other coverage then pays what Medicare does not cover.

The exception is employer coverage: if you are actively employed and covered under your employer's plan, the employer plan pays first, and Medicare pays second. This is why people with active employer coverage can delay Part B without penalty — their employer plan is doing the job Medicare would do.

If you have Medicaid, you can have both Medicaid and Medicare at the same time. Medicaid will help pay your Medicare premiums and cover costs Medicare does not, depending on your income and your state's rules. Contact your state Medicaid office to understand how your coverage will change when you turn 65.

How to prepare before your 65th birthday

Start preparing two to three months before you turn 65. Gather your Social Security number, proof of citizenship (passport, birth certificate, or naturalization papers), and information about any current health coverage. If you have been receiving SSDI or have ESRD or ALS, you should already have received information from Social Security or Medicare, but check your mail and email to confirm.

Decide whether you want Original Medicare (Parts A and B) or a Medicare Advantage plan (Part C). Original Medicare lets you see any doctor who accepts Medicare. Medicare Advantage plans are offered by private insurers and usually have lower premiums but require you to use doctors in their network. Both include prescription drug coverage (Part D) or an equivalent, though you may need to choose a separate Part D plan if you pick Original Medicare.

If you are still working with employer coverage, contact your employer's benefits office to confirm whether you can delay Part B. Get the answer in writing so you have proof if you need to show it to Medicare later.

Frequently Asked Questions

Can I start Medicare before I turn 65?

Only if you have been on Social Security Disability for 24 months, have End-Stage Renal Disease, or have ALS. Otherwise, you must wait until 65. If you think you may may have access to, contact Social Security at 1-800-772-1213 to confirm.

What happens if I sign up late?

You will face a permanent penalty on your Part B premium (10 percent per year you were late) and Part D premium (1 percent per month you were late). The penalty lasts for life. The only exception is if you had creditable coverage during the time you were not signed up.

Do I have to sign up for Medicare if I am still working?

You do not have to sign up for Part B if you have active employer coverage and your employer has 20 or more employees. You can delay Part B without penalty. However, you should still sign up for Part A at 65 — it has no penalty for delay and covers hospital care.

Can I change my mind after I sign up?

Yes, during your Initial Enrollment Period you can change your plan choices. After that period ends, you can make changes only during the annual Open Enrollment Period (October 15 to December 7 each year) or if you have a may have access to life event like losing employer coverage.

What if I do not know my Social Security number?

Contact Social Security at 1-800-772-1213 or visit your local Social Security office. Bring a photo ID and proof of citizenship. You will need your number to sign up for Medicare, so get it before your enrollment window opens.

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.