When You Can Start Medicare: Age Requirements and Your Options

Medicare starts at age 65 for most people

You become may be able to access for Medicare the month you turn 65, regardless of whether you are still working. You do not have to retire to sign up. If you were born on the first of the month, your coverage begins the month before your 65th birthday. If you were born on any other day, coverage begins the month you turn 65.

Some people under 65 can get Medicare if they have been receiving Social Security disability benefits for 24 months, or if they have end-stage renal disease (permanent kidney failure) or ALS (Lou Gehrig's disease). These are the only exceptions to the age 65 rule.

You have a window of time to sign up without penalty. If you miss that window, your premiums go up permanently. The rules differ depending on whether you have other health insurance when you turn 65.

Key Takeaways

Medicare begins the month you turn 65, even if you are still working and have employer health insurance.
You have seven months to sign up without paying a penalty — starting three months before your 65th birthday and ending three months after.
If you have employer coverage when you turn 65, you can delay Medicare Part B without penalty as long as your employer has 20 or more employees.
People under 65 with certain disabilities or kidney failure may be may be able to access for Medicare before their 65th birthday.
Late enrollment penalties are permanent and increase your monthly premiums for as long as you have Medicare.

The seven-month enrollment window and why it matters

Your Initial Enrollment Period lasts seven months total: three months before you turn 65, the month you turn 65, and three months after. During this window, you can sign up for Medicare Part A (hospital insurance) and Part B (medical insurance) without paying a late enrollment penalty.

If you miss this window, you pay a permanent 10% increase on your Part B premium for each year you could have had coverage but did not. This penalty stays with you for life. For example, if you turn 65 in January 2024 but do not sign up until January 2026, you owe a 20% penalty on Part B for the rest of your life.

The same penalty applies to Part D (prescription drug coverage), though the calculation is different — it is 1% per month for each month you went without coverage. These penalties do not go away if you later sign up.

Delaying Medicare if you have employer health insurance

If you are still working at age 65 and your employer offers health insurance, you may be able to delay Medicare Part B without penalty. This works only if your employer has 20 or more employees. You must have actual coverage through that employer — coverage through a spouse's employer counts, but coverage through a retiree plan does not.

When you do sign up for Medicare later, you have eight months from the date your employer coverage ends to enroll without penalty. This is called your Special Enrollment Period. You must sign up during this window or face the permanent late enrollment penalty.

Part A (hospital insurance) is different. Even if you delay Part B, you should sign up for Part A at 65 if you are not paying premiums for it. Part A is usually free if you or your spouse paid Medicare taxes for at least 10 years. Signing up for Part A does not trigger any penalty later, and it covers hospital stays if something unexpected happens.

Medicare before age 65: disability and kidney disease

You can get Medicare before 65 if you have been receiving Social Security Disability Insurance (SSDI) for 24 months. The 24 months starts from when you first became may be able to access for disability payments, not from when you applied. Once you have received SSDI for two years, Medicare begins automatically — you do not have to sign up.

If you have end-stage renal disease (ESRD) — permanent kidney failure requiring dialysis or a transplant — you become may be able to access for Medicare when ready, regardless of age. You must sign up yourself; it does not happen automatically. The same rule applies if you have ALS (amyotrophic lateral sclerosis, also called Lou Gehrig's disease).

If you are under 65 and may be able to access through disability or kidney disease, you still need to understand the enrollment rules. Missing your enrollment window for Part B or Part D still results in permanent penalties, even though you are younger than the standard age.

How to sign up when you turn 65

You can sign up for Medicare three ways: online through Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), 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 ready.

If you are already receiving Social Security benefits when you turn 65, Medicare enrollment happens automatically. You will receive your Medicare card in the mail about two weeks before your coverage begins. You do not need to do anything. If you are not yet receiving Social Security, you must sign up for Medicare separately.

Have your current health insurance information available when you sign up, including policy numbers and coverage dates. If you have questions about which parts of Medicare you need, the Medicare helpline can walk you through your situation over the phone.

What happens if you miss the enrollment window

If you miss your Initial Enrollment Period and you do not have a may have access to reason for a Special Enrollment Period, you can still sign up during the General Enrollment Period, which runs January 1 through March 31 each year. Coverage would begin July 1 of that year. However, you will owe the permanent late enrollment penalty on Part B and Part D.

The only exceptions to the late enrollment penalty are if you had other health insurance that covered you (such as employer coverage or COBRA), or if you are a federal employee or tribal member with specific coverage. If either of these applies to you, you have eight months after that coverage ends to sign up without penalty.

If you are unsure whether you have a may have access to reason to avoid the penalty, contact Medicare before you sign up. They can review your specific situation and tell you whether a penalty will explore.

Understanding Part A, Part B, Part D, and Medigap timing

Part A (hospital insurance) and Part B (medical insurance) are the core of Medicare. Most people sign up for both at 65. Part A is usually free; Part B has a monthly premium that changes each year.

Part D (prescription drug coverage) is optional but important if you take medications. You have the same seven-month enrollment window as Part A and Part B. If you go without Part D coverage and later sign up, you pay a permanent penalty based on how many months you were uninsured.

Medigap (supplemental insurance) helps pay costs that Medicare does not cover, such as copayments and deductibles. You have the best rates and may provide acceptance if you sign up for Medigap within six months of starting Part B. After that window, insurers can charge more or deny you based on your health history. This is different from the late enrollment penalty, but it still costs you money if you wait.

Frequently Asked Questions

Do I have to retire to sign up for Medicare at 65?

No. You can sign up for Medicare at 65 even if you are still working and have employer health insurance. If your employer has 20 or more employees, you can delay Part B without penalty, but you should still sign up for Part A.

What if I turn 65 on the first day of the month?

Your Medicare coverage begins the month before your birthday. For example, if you turn 65 on January 1, your coverage starts December 1. Your enrollment window still opens three months before your birthday.

Can I sign up for Medicare online?

Yes. Go to Medicare.gov and select "Sign up for Medicare." You can also call 1-800-MEDICARE or visit your local Social Security office. Online is usually the fastest option.

What if I miss the enrollment window by a few months?

You can sign up during the General Enrollment Period (January 1 through March 31), with coverage starting July 1. However, you will owe a permanent late enrollment penalty on Part B and Part D unless you have a may have access to reason, such as employer coverage that ended.

Does Medicare start automatically when I turn 65?

Only if you are already receiving Social Security benefits. If you are not yet receiving Social Security, you must sign up for Medicare yourself during your enrollment window. You have seven months to do so without penalty.

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.