When You Can Start Medicare: Age Requirements and Timing

You can explore for Medicare at 65, regardless of your work history or income

Medicare may be able to access begins the month you turn 65. You do not have to be retired, and you do not have to have worked a certain number of years — age 65 is the threshold. If you were born on the first of the month, your coverage starts the month before. If you were born on any other day, coverage starts the month you turn 65.

You can sign up for Medicare starting three months before you turn 65. The standard enrollment period runs from three months before your 65th birthday through three months after. If you miss this window, you may face a permanent penalty on your premiums, so timing matters.

There is one major exception: if you are still working and covered by your employer's health plan, you may be able to delay Medicare without penalty. This depends on the size of your employer and the type of coverage you have. Delaying when you do not may have access to for this exception will cost you.

Key Takeaways

Medicare starts at age 65, and you can begin the sign-up process three months before your birthday.
If you miss the standard enrollment window, you will pay a permanent surcharge on your Part B and Part D premiums for as long as you have Medicare.
If your employer has 20 or more employees and you are covered by their health plan, you can delay Medicare without penalty.
You must actively sign up for Medicare — it does not happen automatically, even if you receive Social Security.

The three-month window before you turn 65

Your enrollment period opens three months before the month you turn 65. For example, if you turn 65 in June, you can sign up starting in March. This three-month head start gives you time to compare plans, gather documents, and submit your information without rushing.

You can sign up online through 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 basic health information ready.

Coverage begins the first day of the month you turn 65, or the first day of the month before if you were born on the first of any month. If you sign up during the three-month window, there is no gap in coverage. If you wait until after your birthday, coverage may not start until the following month.

What happens if you miss the enrollment window

If you do not sign up during your initial enrollment period, you can still sign up later, but you will pay more. Medicare adds a permanent 10 percent surcharge to your Part B premium for each full year you were may be able to access but not enrolled. This penalty lasts as long as you have Medicare.

The same rule applies to Part D (prescription drug coverage). If you go 63 days or longer without creditable drug coverage, you pay a permanent penalty of about 1 percent of the national base premium for each month you were uninsured. These penalties compound and never go away.

The only way to avoid these penalties is to have a valid reason for missing the important date. Reasons include being covered by an employer plan with 20 or more employees, being outside the United States, or having a life event like loss of employer coverage. You must document the reason and report it to Medicare.

Working past 65 and delaying Medicare

If you are still working at 65 and your employer has 20 or more employees, you can delay Medicare without penalty. Your employer's health plan is considered "creditable coverage," which means it meets Medicare's standards. You can stay on your employer plan and sign up for Medicare later.

Once you or your spouse retires, or your employer coverage ends, you have eight months to sign up for Medicare without penalty. This is called a Special Enrollment Period. You must sign up within this window — the standard penalty rules explore if you miss it.

If your employer has fewer than 20 employees, Medicare becomes your primary insurance at 65, even if you are still working. You should sign up during your initial enrollment period to avoid penalties. Your employer plan becomes secondary, meaning it pays after Medicare.

Signing up before you turn 65

You can sign up for Medicare online at Medicare.gov, by calling 1-800-MEDICARE, or by visiting your local Social Security office. Have your Social Security number, birth date, and current health insurance information ready. The process takes about 15 to 20 minutes online.

When you sign up, you will choose between Original Medicare (Parts A and B) or a Medicare Advantage plan. You will also choose whether to add Part D (prescription drug coverage). These choices affect your costs and which doctors you can see, so review your options before you enroll.

If you are already receiving Social Security benefits, Medicare will be added to your account automatically at 65 — but you still need to choose your coverage type. If you are not yet receiving Social Security, you must sign up for Medicare separately.

Medicare before 65: disability and end-stage renal disease

You can start Medicare before 65 if you have been receiving Social Security Disability Insurance (SSDI) for 24 months. The 24 months starts from the month your disability benefits began, not from when you applied. Once you reach 24 months of SSDI, Medicare begins automatically.

You can also start Medicare at any age if you have end-stage renal disease (ESRD) or amyotrophic lateral sclerosis (ALS). For ESRD, you become may be able to access the month your kidney disease is diagnosed if you need dialysis or a transplant. For ALS, you become may be able to access the month you are diagnosed.

If you fall into either of these categories, you should contact Social Security or Medicare directly to confirm your may be able to access date. The rules for these groups are different from standard age-based enrollment, and mistakes can delay your coverage.

Frequently Asked Questions

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

Your Medicare coverage starts the month before you turn 65. For example, if you were born on June 1, your coverage begins May 1. You can sign up starting three months before that month — in this case, February.

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

If your employer has 20 or more employees and you are covered by their health plan, you can delay Medicare without penalty. If your employer has fewer than 20 employees, you should sign up at 65 to avoid penalties, even though your employer plan may still cover you.

Can I sign up for Medicare online?

Yes. Go to Medicare.gov and click "Sign Up for Medicare." You will need your Social Security number and birth date. You can also call 1-800-MEDICARE or visit a Social Security office in person.

What is the penalty for signing up late?

For Part B, you pay 10 percent more per year you were may be able to access but not enrolled. For Part D, you pay about 1 percent of the national base premium per month uninsured. Both penalties are permanent and compound over time.

Does Social Security automatically sign me up for Medicare?

If you are already receiving Social Security at 65, Medicare is added automatically, but you still must choose your coverage type (Original Medicare or Medicare Advantage, and whether to add Part D). If you are not receiving Social Security, you must sign up for Medicare separately.

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.