When You Can Start Medicare: Age Requirements and Special Cases

The standard age is 65, but you may be able to start earlier

You become may be able to access for Medicare at age 65. This is the rule for most people, and it applies whether you are still working or retired. You do not have to stop working to sign up, and your may be able to access does not depend on your income or savings.

However, you can start Medicare before 65 in specific situations. If you have been receiving Social Security Disability Insurance (SSDI) for 24 months, you become may be able to access at any age. If you have end-stage renal disease (ESRD) or amyotrophic lateral sclerosis (ALS), you may be may be able to access when ready, regardless of age or work history. These are the only pathways to Medicare before 65.

Key Takeaways

You are may be able to access for Medicare at age 65, and you should sign up during your initial enrollment period, which starts three months before the month you turn 65.
If you have received SSDI for 24 consecutive months, you become may be able to access for Medicare before age 65, usually at age 64 or younger depending on when your disability began.
People with end-stage renal disease or ALS can start Medicare at any age and should contact Social Security or Medicare directly to begin the process.
Signing up late without a valid reason can result in a permanent penalty on your Part B and Part D premiums, so timing your enrollment matters.

How the initial enrollment period works at 65

Your initial enrollment period is a seven-month window centered on your 65th birthday. It runs from three months before the month you turn 65 through three months after. For example, if you turn 65 in June, your period runs from March through September.

You should sign up during this window, even if you plan to keep working. Medicare Part A (hospital insurance) is usually free at 65, so there is no cost reason to delay. Part B (medical insurance) has a monthly premium, but signing up on time avoids a late-enrollment penalty that increases your premium permanently.

If you miss this window and do not have a valid reason — such as employer coverage or a may have access to life event — you will pay a higher Part B premium for as long as you have Medicare. The penalty is 10 percent of the standard premium for each full year you were late, and it stacks year after year.

Starting Medicare before 65 through SSDI

If you receive SSDI, you become may be able to access for Medicare after you have been on SSDI for 24 consecutive months. The 24-month clock starts from the month your SSDI payments began, not from the month you filed.

Once you hit 24 months on SSDI, Medicare starts automatically the following month. You do not need to contact anyone or fill out a separate form. Social Security will send you information about your Medicare coverage, usually a few weeks before it begins. Your Medicare Part A is free, and you can choose whether to enroll in Part B.

If you are on SSDI and approaching 24 months, check your Social Security statement online or call Social Security at 1-800-772-1213 to confirm your start date. This gives you time to understand your coverage options before Medicare begins.

Starting Medicare with end-stage renal disease or ALS

People with end-stage renal disease (ESRD) — permanent kidney failure requiring dialysis or transplant — can start Medicare at any age. The same applies to people with ALS (amyotrophic lateral sclerosis, also called Lou Gehrig's disease). These are the only two conditions that override the age requirement.

For ESRD, Medicare typically begins the first day of the month you start dialysis or the month of your transplant, whichever comes first. For ALS, Medicare begins the first day of the month after your ALS diagnosis is medically documented.

You do not sign up for this coverage yourself. Your dialysis center, transplant team, or neurologist will report your condition to Social Security, which will contact you to confirm your information. If you do not hear from Social Security within a few weeks of starting treatment or receiving your diagnosis, call 1-800-772-1213 to check the status.

What happens if you are still working at 65

You can stay on your employer's health plan and delay Medicare Part B if your employer has 20 or more employees and you are actively working. This is called group health plan coverage. You can wait to sign up for Part B without penalty as long as you are covered by your employer's plan and actively employed.

When you leave your job or your employer coverage ends, you have a special enrollment period of eight months to sign up for Part B without penalty. You must sign up during this window or pay the late-enrollment penalty. Part A (hospital insurance) should still start at 65 even if you delay Part B.

If you are unsure whether your employer plan qualifies, ask your benefits administrator or call Medicare at 1-800-MEDICARE (1-800-633-4227). Getting this wrong can cost you thousands in penalties over time.

Delaying Medicare past 65

You can delay Medicare Part B past 65 if you have may have access to coverage — either an employer plan or coverage from a spouse's employer. You cannot delay Part A without penalty unless you are still working and covered by an employer plan with 20 or more employees.

If you delay Part B because of employer coverage, you must sign up within eight months of losing that coverage. If you delay without may have access to coverage, you will pay a late-enrollment penalty of 10 percent per year for as long as you have Medicare.

Part D (prescription drug coverage) also has a late-enrollment penalty if you delay without creditable coverage. The penalty is one percent of the national base beneficiary premium for each month you were late, and it also sticks with you permanently. If you go without any drug coverage for 63 days or more, you lose the right to claim you had creditable coverage.

How to sign up for Medicare

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 — you can complete the process in 15 to 20 minutes if you have your Social Security number and birth certificate information handy.

If you are already receiving Social Security retirement or SSDI benefits, you may be signed up automatically. Check your Social Security account online or call 1-800-772-1213 to confirm. If you are not automatically enrolled, sign up during your initial enrollment period to avoid penalties.

Have your Social Security number, date of birth, and citizenship or immigration status ready. If you are signing up for Part B, you will also choose whether to enroll in Part D (prescription drug coverage) at the same time. You can change your Part D plan every year during the annual enrollment period, which runs from October 15 through December 7.

Frequently Asked Questions

Can I start Medicare before 65 if I am disabled but not on SSDI?

No. The only way to get Medicare before 65 due to disability is to have been receiving SSDI for 24 consecutive months. If you are disabled but not yet on SSDI, you would need to file for SSDI first, wait 24 months, and then Medicare would begin. If you have ESRD or ALS, those conditions override the age requirement regardless of SSDI status.

What if I turn 65 while still working full-time?

You should still sign up for Medicare during your initial enrollment period. You can keep your employer coverage and Medicare at the same time. Medicare becomes your primary payer once you are enrolled, and your employer plan pays second. Signing up on time avoids the Part B late-enrollment penalty.

Do I have to sign up for Part B at 65?

You must sign up for Part B at 65 unless you have may have access to employer coverage. If you have group health plan coverage from an active employer with 20 or more employees, you can delay Part B. Otherwise, signing up during your initial enrollment period avoids a permanent penalty on your premiums.

What if I miss my initial enrollment period?

You can still sign up for Medicare after your initial enrollment period ends, but you will pay a late-enrollment penalty on Part B and Part D premiums for as long as you have Medicare. The penalty is 10 percent of the standard premium for each full year you were late. The only way to avoid this is to have had a valid reason, such as employer coverage or a may have access to life event.

How do I know if my SSDI has been active for 24 months?

Check your Social Security statement online at ssa.gov, or call Social Security at 1-800-772-1213. They can tell you the exact month your SSDI began and when you will reach 24 months. Medicare should start automatically the month after you hit 24 months, but confirming in advance prevents surprises.

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.