When to Sign Up for Medicare: Age and Timing Rules

You can sign up for Medicare starting at age 65, but the exact timing matters for your costs

Medicare may be able to access begins at age 65 for most people. You do not have to wait until your 65th birthday to start the process — you can sign up during the three months before you turn 65, the month you turn 65, or the three months after. This seven-month window is called your Initial Enrollment Period. If you miss this window, you may pay higher premiums for the rest of your life, so the timing of when you sign up is worth getting right.

Some people become may be able to access for Medicare before age 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), you can sign up at any age. This guide focuses on the standard age-65 path, which covers most people.

Key Takeaways

Your Initial Enrollment Period runs for seven months: three months before your 65th birthday, the month you turn 65, and three months after.
If you delay signing up past your Initial Enrollment Period without a valid reason, you will pay a permanent penalty on your Part B and Part D premiums.
You can sign up online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
If you are still working and covered by your employer's health plan, you may be able to delay Part B without penalty — but you must tell Medicare about your coverage.

Your seven-month enrollment window and what happens if you miss it

Your Initial Enrollment Period starts three months before the month you turn 65. For example, if you turn 65 in June, your enrollment period begins in March. It ends three months after your birthday month — so in this example, it would end in September. During these seven months, you can sign up for Medicare Part A (hospital insurance) and Part B (medical insurance) without any penalty.

If you do not sign up during your Initial Enrollment Period, you enter a General Enrollment Period that runs from January 1 to March 31 each year. You can sign up then, but you will pay a penalty. For Part B, the penalty is 10 percent of the standard premium for each full 12 months you delayed — and this penalty stays with you permanently. For Part D (prescription drug coverage), the penalty is roughly 1 percent of the national average premium for each month you were without coverage, also permanent. These penalties add up quickly, so signing up on time saves you money over your lifetime.

When you can delay Part B without a penalty

If you are still working at age 65 and covered by your employer's health plan, you may be able to delay Part B without paying a penalty. This is called creditable coverage. Your employer's plan must be based on your current employment — coverage through a spouse's employer also counts. Medicare must know that you have this coverage, so you need to tell them when you sign up for Part A.

When you leave your job or lose your employer coverage, you have eight months to sign up for Part B without penalty. This eight-month window is separate from your Initial Enrollment Period. If you miss this window, the standard Part B penalty applies. Part A (hospital insurance) does not have the same penalty rule, so you can delay it longer if you have coverage through your employer.

How to sign up for Medicare at 65

You have three main ways to sign up. The easiest is online at Medicare.gov — you can create an account and complete your process without leaving home. You will need your Social Security number, birth date, and citizenship or immigration status. The process takes about 10 minutes.

You can also call 1-800-MEDICARE (1-800-633-4227). Representatives are available Monday through Friday, 8 a.m. to 8 p.m. Eastern time, and Saturday, 8 a.m. to 4 p.m. Eastern time. They can answer questions about your specific situation and help you sign up over the phone. If you are deaf or hard of hearing, you can use TTY at 1-877-486-2048.

A third option is to visit your local Social Security office in person. You can find the nearest office at ssa.gov/locator. Bring your Social Security card, proof of citizenship or immigration status, and proof of age. Staff can help you sign up for Medicare at the same time you handle any Social Security business.

What happens after you sign up

After you submit your process, Medicare will review it and send you a decision letter. This usually takes about two weeks. Once you are approved, you will receive your Medicare card in the mail — typically within two weeks of approval, though it can take longer. Your coverage usually starts on the first day of the month in which you turn 65, or the first day of the month after you sign up, whichever is later.

Before your coverage starts, you should choose a plan. If you do nothing, you will be enrolled in Original Medicare (Part A and Part B) automatically. But you can also choose a Medicare Advantage plan (Part C) or a Medigap plan instead. These choices have different costs and coverage rules, and you have until December 7 of your first year on Medicare to make changes. After that, you can only change plans during the annual open enrollment period from October 15 to December 7.

Special situations: disability, ESRD, and ALS

If you receive SSDI, you become may be able to access for Medicare after you have been on disability for 24 months. You do not have to be age 65. Medicare will contact you automatically when you reach 24 months of SSDI, and your coverage will start the month after you hit that milestone. You can also sign up earlier if you want — there is no penalty for doing so.

If you have end-stage renal disease (ESRD) — permanent kidney failure requiring dialysis or a transplant — you can sign up for Medicare at any age. Your coverage can start as early as the first day of the month you begin dialysis treatment or the month of your transplant. If you have ALS, you become may be able to access when ready upon diagnosis, with no waiting period. In both cases, contact Medicare directly to sign up, as the process is different from the standard age-65 enrollment.

Frequently Asked Questions

What if I turn 65 while I am still working?

You can still sign up for Medicare at 65. If your employer offers health coverage and you are enrolled in it, you can delay Part B without penalty — but you must tell Medicare about your employer coverage when you sign up for Part A. When you leave your job, you have eight months to sign up for Part B without penalty.

Can I sign up for Medicare before I turn 65?

Yes. You can sign up starting three months before your 65th birthday. Many people sign up at age 64 and a few months, so their coverage is ready on their birthday. You cannot sign up more than three months early.

What if I miss my Initial Enrollment Period?

You can still sign up during the General Enrollment Period (January 1 to March 31 each year), but you will pay a permanent penalty on Part B and Part D premiums. The penalty is 10 percent of the Part B premium for each full 12 months you delayed, and roughly 1 percent of the average Part D premium for each month without coverage.

Do I have to sign up for Part D when I turn 65?

You do not have to, but if you go without prescription drug coverage and do not have other creditable coverage, you will pay a penalty when you do sign up. The penalty is permanent. If you do not take prescription drugs, you can skip Part D, but tell Medicare so they know you made an active choice.

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

You can sign up for Medicare at 65 if you are a permanent resident (green card holder) and have lived in the United States for at least five years. If you are not a permanent resident, contact Medicare directly at 1-800-MEDICARE to discuss your situation, as the rules vary by immigration status.

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.