When You're Eligible for Medicare: Age and Other Routes

You become may be able to access for Medicare at 65, but you can start earlier if you have a disability or end-stage renal disease

The standard age to enroll in Medicare is 65. You do not have to wait until your birthday month — you can sign up starting three months before you turn 65, during the month you turn 65, or up to three months after. However, age 65 is not the only path. If you are under 65 and have received Social Security disability benefits for 24 months, or if you have end-stage renal disease (ESRD) or amyotrophic lateral sclerosis (ALS), you may be able to enroll in Medicare now, regardless of age.

If you do not sign up during your initial enrollment window — the seven-month period that includes the three months before, the month of, and three months after your 65th birthday — you may face a permanent penalty on your premiums. The penalty amount depends on how long you waited and which parts of Medicare you are enrolling in. The longer you delay without a valid reason, the higher your monthly costs will be for as long as you have Medicare.

Key Takeaways

You can enroll in Medicare starting three months before you turn 65, during your birth month, or within three months after.
If you have been on Social Security disability for 24 months, you become may be able to access for Medicare before age 65.
People with end-stage renal disease or ALS can enroll in Medicare at any age.
Delaying enrollment past your initial window without a valid reason results in a permanent increase to your monthly premiums.
You can sign up through Medicare.gov, by phone, or in person at a Social Security office.

How the age 65 enrollment window works

Your initial enrollment period is seven months long and centers on your 65th birthday. It starts three months before the month you turn 65 and ends three months after. For example, if you turn 65 in June, your window opens in March and closes in September. During this time, you can enroll in any part of Medicare without waiting periods or penalties.

You do not have to enroll on your birthday itself. Many people sign up earlier to avoid gaps in coverage. If you are still working and covered by an employer health plan at 65, you may have a reason to delay, but you should still understand the rules before you do. Some people mistakenly think they can enroll later without penalty if they are covered by a job — that is only true under specific circumstances, and the burden is on you to prove it.

Becoming may be able to access before 65 through disability

If you have been receiving Social Security Disability Insurance (SSDI) benefits for 24 consecutive months, you become may be able to access for Medicare at that point, even if you are much younger than 65. The 24-month clock starts from the month your disability benefits begin, not from the month you applied. Once you reach 24 months of benefits, Medicare coverage begins automatically — you do not need to sign up separately.

The same rule applies if you are receiving benefits as a family member of someone who is disabled or retired. If you are an adult child receiving benefits on a parent's record and you have been receiving those benefits for 24 months, you become may be able to access for Medicare.

If you have been denied Social Security disability benefits and are appealing the decision, you do not yet may have access to for Medicare through disability. You become may be able to access only once your benefits are approved and you have received them for 24 months.

End-stage renal disease and ALS: Medicare at any age

Two conditions allow you to enroll in Medicare regardless of age: end-stage renal disease (ESRD) and amyotrophic lateral sclerosis (ALS). If you have ESRD and need dialysis or a kidney transplant, you can enroll in Medicare when ready. Your coverage can begin as early as the first day of the month in which you start dialysis, or the month of your transplant.

If you have been diagnosed with ALS, you become may be able to access for Medicare right away, without any waiting period. You do not have to wait for Social Security to approve a disability claim. Your Medicare coverage can start in the month you are diagnosed, though you will need to provide medical documentation of the diagnosis when you sign up.

What happens if you miss your enrollment window

If you do not sign up during your initial seven-month window and you do not have a valid reason for the delay, you will pay a permanent penalty. For Part B (medical insurance), the penalty is 10 percent of the standard premium for each full year you were may be able to access but not enrolled. This penalty stays with you for life, even if you eventually sign up.

For Part D (prescription drug coverage), the penalty is calculated differently — it is based on the national average premium at the time you enroll, multiplied by the number of months you were without coverage. This penalty also lasts as long as you have Part D coverage.

A valid reason to delay enrollment without penalty is called "creditable coverage" — this usually means you were covered by an employer health plan or a spouse's employer plan while you were working. If you had creditable coverage, you have an eight-month grace period after that coverage ends to enroll in Medicare without penalty. You will need to provide proof of that coverage when you sign up.

How to sign up for Medicare

You can enroll in Medicare through three main routes: online at Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office. If you are already receiving Social Security benefits, you may be enrolled automatically in Parts A and B when you turn 65, but you should verify this and make any choices about Part D or Medigap coverage yourself.

When you sign up, you will choose between Original Medicare (Part A and Part B) and Medicare Advantage (Part C). You will also decide whether to enroll in Part D for prescription drug coverage. These choices affect your costs and which doctors and pharmacies you can use. If you are unsure which option fits your situation, you can speak with a counselor at your State Health Insurance information Program (SHIP), which offers free, unbiased information.

Special situations that affect your enrollment age

If you are a federal employee, railroad retiree, or have coverage through the Veterans Health Administration, different rules may explore to when you can or should enroll in Medicare. Federal employees and railroad retirees often have coordination rules with Medicare. Veterans can use VA benefits alongside Medicare, but the timing of your enrollment can affect how your benefits work together.

If you are a non-citizen, you must have been a permanent resident for at least five years and meet other requirements to be may be able to access for Medicare at 65. Undocumented immigrants are not may be able to access for Medicare. If you are unsure about your status, contact Medicare directly or visit your local Social Security office.

If you are still working at 65 and covered by your employer's health plan, you can delay enrolling in Part B without penalty, but you must enroll in Part A. Part A has no premium for most people, and delaying it can result in a penalty. Part B is where the penalty applies if you delay without creditable coverage.

Frequently Asked Questions

Can I enroll in Medicare before I turn 65?

Yes, if you have been receiving Social Security disability benefits for 24 months, or if you have end-stage renal disease or ALS. Otherwise, you must wait until three months before your 65th birthday to sign up. You cannot enroll early straightforward because you want to.

What is the penalty for signing up late?

For Part B, you pay 10 percent of the standard premium for each full year you delayed. For Part D, the penalty is based on the national average premium multiplied by the months you were uninsured. Both penalties are permanent. If you had creditable coverage from an employer, you have an eight-month grace period after that coverage ends.

Do I have to sign up at 65 if I am still working?

You must enroll in Part A at 65, even if you are working, because delaying Part A carries a penalty. You can delay Part B without penalty if you are covered by an employer health plan, but you must sign up within eight months of leaving that job or retiring.

What if I turned 65 and did not sign up — can I still enroll?

Yes, but you may face a permanent penalty on your premiums. You can enroll during the General Enrollment Period, which runs from January 1 to March 31 each year, with coverage starting July 1. However, the penalty will explore unless you had creditable coverage that extended past your initial window.

Does Medicare start the month I turn 65 or the month after?

If you sign up during your initial enrollment window, Medicare Part A coverage typically begins on the first day of the month you turn 65. Part B coverage also begins the first of that month if you enroll before your birthday, or the first of the following month if you enroll after. Confirm the exact date when you sign up.

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.