When You Can Sign Up for Medicare: Age and Timing Rules

You become may be able to access for Medicare at 65, but the exact month you can enroll depends on your birthday

Medicare may be able to access starts the month you turn 65. You do not have to wait until your birthday itself — the month counts. For example, if you turn 65 on March 15, you can enroll starting in March. If you turn 65 on March 1, you can also enroll starting in March.

You can sign up for Medicare before you turn 65, during a window that opens three months before the month you turn 65 and closes three months after. This seven-month window is called your Initial Enrollment Period. If you miss this window and do not have coverage through an employer or union, you will face a permanent penalty on your premiums.

There are exceptions: you may become may be able to access before 65 if you have received Social Security Disability Insurance (SSDI) for 24 months, or if you have end-stage renal disease or ALS (amyotrophic lateral sclerosis). These situations are less common, but they do exist.

Key Takeaways

You become may be able to access for Medicare the month you turn 65, regardless of the specific date within that month.
Your Initial Enrollment Period runs for seven months: three months before the month you turn 65, the month itself, and three months after.
If you miss your Initial Enrollment Period and have no employer or union coverage, you will pay a permanent increase on your Part B and Part D premiums.
You can enroll online through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
People with SSDI, end-stage renal disease, or ALS may become may be able to access before 65.

How to find your Initial Enrollment Period based on your birthday

Your Initial Enrollment Period is always a seven-month window. The month you turn 65 is in the middle of it. Three months before and three months after that month make up the rest.

If you turn 65 in June, for example, your Initial Enrollment Period runs from March through September. If you turn 65 in January, it runs from October of the previous year through April. The Social Security Administration website has a tool where you can enter your birth date and see your exact window.

You should enroll as early in this window as you can. Even though you have seven months, processing can take time, and waiting until the last month leaves no room for delays. Many people enroll in the first month their window opens.

What happens if you miss your Initial Enrollment Period

If you do not enroll during your Initial Enrollment Period and you do not have coverage through a current employer or union, you will face a late enrollment penalty. This penalty is permanent — it stays on your account for as long as you have Medicare.

For Part B (medical insurance), the penalty is 10 percent of the standard premium for each full 12-month period you were not enrolled. For Part D (prescription drug coverage), the penalty is 1 percent of the national base beneficiary premium for each month you were not enrolled. These amounts change each year, so the penalty you pay will depend on when you enroll and what the current premiums are.

The only way to avoid this penalty is to have had creditable coverage — health insurance through a current employer, a spouse's current employer, or a union — during the time you were not enrolled in Medicare. If you had that coverage, you can enroll later without penalty, but you will need to show proof of it when you sign up.

Exceptions: becoming may be able to access before 65

Most people become may be able to access at 65, but three groups can enroll earlier. If you have been receiving SSDI for 24 months, you become may be able to access for Medicare automatically at age 65 — but you may have already been enrolled for up to 24 months before that. The Social Security Administration will contact you about three months before you turn 65 to explain your options.

If you have end-stage renal disease (permanent kidney failure requiring dialysis or a transplant), you can enroll in Medicare regardless of age. You can sign up as soon as you start dialysis treatment or receive a transplant. If you are already on dialysis when you turn 65, your coverage will continue without interruption.

If you have been diagnosed with ALS (Lou Gehrig's disease), you become may be able to access for Medicare when ready, with no age requirement and no waiting period. You can enroll as soon as you have a diagnosis from a doctor.

How to enroll during your Initial Enrollment Period

You have three main ways to enroll. The easiest for most people is online through Medicare.gov. You will need to create an account, provide your Social Security number, and answer questions about your health coverage history. The online process usually takes 15 to 20 minutes.

You can also call 1-800-MEDICARE (1-800-633-4227). A representative will walk you through the enrollment process over the phone. The line is open Monday through Friday, 8 a.m. to 8 p.m. Eastern time, and Saturday 9 a.m. to 1 p.m. Eastern time. Wait times are often shorter early in the morning or on weekday afternoons.

A third option is to visit your local Social Security office in person. You can find the nearest office on the Social Security Administration website. Bring your Social Security card, proof of citizenship or legal residency, and proof of age (a birth certificate or passport). Staff can enroll you on the spot, though you may need to wait for an appointment.

What to do if you think you missed your window

If you believe you missed your Initial Enrollment Period, contact Medicare or Social Security right away. In some cases, you may have a second chance to enroll without penalty. This can happen if you had a Special Enrollment Period — a circumstance like losing employer coverage, moving to a new state, or a change in your family status that gives you extra time to enroll.

You may also be able to enroll without penalty if you can prove you had creditable coverage during the time you were not enrolled. Gather any documents showing you had health insurance — pay stubs listing insurance, letters from your employer's benefits department, or insurance cards from that period. Call 1-800-MEDICARE with these documents ready, and a representative can review your situation.

If you do not may have access to for a Special Enrollment Period and did not have creditable coverage, you can still enroll, but the late enrollment penalty will explore. It is still worth enrolling rather than going without coverage.

Frequently Asked Questions

Can I enroll in Medicare before I turn 65 if I am still working?

Yes. Your age is what matters, not your employment status. You can enroll during your Initial Enrollment Period even if you are working full-time. However, if you are covered through your employer's health plan, you may want to check with your benefits department first — some employers coordinate with Medicare in ways that affect your coverage.

What if my birthday is on the first or last day of the month?

It does not matter. The entire month counts as the month you turn 65. If you turn 65 on January 1 or January 31, your Initial Enrollment Period is the same: October of the previous year through April of the current year.

Do I have to enroll in all parts of Medicare at the same time?

No. You can enroll in Part A (hospital insurance) and Part B (medical insurance) at different times during your Initial Enrollment Period. However, Part D (prescription drug coverage) has its own rules — if you do not enroll when you first become may be able to access and you go without drug coverage, you will face a permanent penalty when you do enroll.

What if I am not a U.S. citizen?

You must be a U.S. citizen or a lawful permanent resident (green card holder) to enroll in Medicare. You must also have lived in the United States for at least five consecutive years. If you meet these requirements, your age may be able to access is the same as for citizens.

Can I delay enrolling in Medicare if I have good health insurance through my employer?

Yes, but only if your employer has 20 or more employees. In that case, you can delay Part B enrollment without penalty as long as you stay covered through that employer. You will still need to enroll in Part A at 65 unless you are still working and meet other conditions. When you do leave that job, you will have eight months to enroll in Part B 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.