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How to Sign Up for Medicare

Your step-by-step guide to enrolling in this federal health insurance program

11-minute read

Article 8 out of 15 in Medicare Basics

Dena Bunis and Kimberly Lankford,

Updated August 27, 2026

AARP

Reviewed by

Xavier Vaughn, MPH

En español

Updated August 27, 2026

AARP (Source: Getty Images)

Key takeaways

Start looking at your options before age 65.
Some enrollment is automatic. Is yours?
But most people will need to apply for Medicare.
Free personalized and local advice is available.
Sign up online for Medicare in 3 simple steps.

Turning 65 is a milestone for most Americans because they become eligible for Medicare health care coverage.

But you can sign up only at certain times, and you need to make important decisions about your coverage, so doing your homework before your birthday is a good idea. If you make Medicare enrollment mistakes, you could end up with lifetime late penalties and expensive coverage gaps.

Here are the most important things you need to know about when and how to enroll in Medicare.

First, you may not need to apply

If you’ve been collecting Social Security retirement, Social Security Disability Insurance (SSDI) or Railroad Retirement Board payments for four months before your 65th birthday, you’ll be automatically enrolled in Part A hospitalization and Part B doctor services and will get your Medicare card about three months before your birthday. Your coverage will start the first day of the month you were born or a month earlier if you were born on the first of a month.

If you’re younger but have been eligible for SSDI for 24 months, you’ll also be automatically enrolled starting in the 25th month of your disability. If you have amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, you’ll get Medicare as soon as your disability payments start.

Kidney patients be aware: If you’re in permanent kidney failure, also known as end-stage renal disease, your coverage can start as early as the first month if you’ve been trained in home dialysis and your doctor says you’re able to do your treatments at home. Most patients will become eligible for Medicare in their fourth month of dialysis.

The rub is that you’re eligible but not automatically enrolled. You’ll still have to apply for Part A and Part B. If you sign up later, your coverage will apply retroactively.

Your Medicare card isn’t everything. Once you have Part A and Part B you still have choices to make.

You’ll have 63 days after your Medicare coverage begins to enroll in a Part D prescription plan or a Medicare Advantage plan with drug coverage. If you’re in a retiree plan that is at least as good or better than Medicare’s offerings — called creditable coverage — that’s considered the equivalent and is acceptable. Without one of these forms of drug coverage, you could face lifelong penalties when you do want to sign up.

If you choose original Medicare and buy Part D, finding a Medicare supplement plan, better known as Medigap, is also a good idea. Your six-month Medigap open enrollment period begins the month your Part B starts, and during that enrollment period you can’t be turned down because of your health.

Most people will need to enroll themselves

The bottom line: If you haven’t been receiving Social Security benefits for four months before your 65th birthday, you’ll have to sign up for yourself.

That time is called your initial enrollment period, and it’s when you can enroll in Medicare without fear of a late penalty. Your initial enrollment period centers on your birthday month, starting three months before and lasting three months after for a total of seven months.

This is also the time to sign up if you’ve been getting your insurance through the Affordable Care Act’s (ACA) health insurance marketplace, Consolidated Omnibus Budget Reconciliation Act (COBRA) coverage because you lost your job, retiree health insurance from a former employer — unless you’re already getting Social Security — or the Tricare military health plan.

More people delay retirement. Turning 65 once meant employment was winding down. But now, those approaching 65 won’t reach full retirement age for Social Security until 67, so many continue to work.

The confusion comes because Medicare continues to follow the same age rules as when it began in 1966. Medicare today primarily serves Americans 65 and older, but fewer and fewer are totally retired.

Some delay Medicare. Most people are first eligible for Medicare at age 65. If you or your spouse still work, you might want to stay on your employer plan because it likely covers more than Medicare, such as dental and vision care.

That’s possible if you work for a company with 20 or more employees.

You can delay Part B, which has a monthly cost like private health insurance. But you may decide to sign up for Part A, which becomes a second potential payer after your main insurance if you’re hospitalized, because you’ve worked enough to get it premium-free.

If you work for a larger employer with a high-deductible health plan, contribute to a health savings account (HSA) and want to continue the pre-tax deductions, you should delay both Part A and Part B. Don’t sign up for Part A or Part B yet, but save the paperwork showing you’re insured to ensure you don’t face penalties later.

Some should never delay. If you work for a business with fewer than 20 employees, sign up for both Part A and Part B during your initial enrollment period. Otherwise, you’ll find that your insurance becomes secondary and won’t pay for health care costs that Medicare would cover.

You could be on the hook for thousands of dollars if you’re hospitalized or have outpatient surgery. Your work insurance won’t pay even if those costs would have been covered when you were younger.

If your small business’ health insurance includes an HSA, you can keep the money you’ve already saved but should quit the plan several months ahead and sign up for Medicare at 65. That’s because your insurance will become secondary, but the IRS will penalize you if you or your employer set aside money in a health savings account while you’re on Medicare.

Confused? Get personalized advice

Your State Health Insurance Assistance Program (SHIP), federally financed but locally maintained in your state or territory, offers free, unbiased individual guidance for your circumstances. The toll-free national number, 877-839-2675, can connect you with your local SHIP.

You also can find your area’s SHIP through an online directory. SHIP centers’ one-on-one counseling sessions cover a multitude of Medicare questions and averaged more than 30 minutes each in 2021, the latest information available.

How to sign up for Medicare in 3 steps

You may not realize this: The Social Security Administration (SSA) handles Medicare enrollment even though the Centers for Medicare & Medicaid Services (CMS) runs the program.

When you begin getting Social Security payments and Part B, the premium will be deducted from your monthly check.

If you have a secure internet connection and are comfortable using online accounts, the easiest way to sign up for Medicare is through Social Security’s website. It’s available 24/7, so you don’t have to work around SSA’s phone-in hours of 8 a.m. to 7 p.m. in most time zones or wait a month or more for an in-person appointment after you call 800-772-1213.

Walk-in service at local offices is largely a thing of the past.

1. Create an online account. If you don’t already have a my Social Security online account, you’ll have to establish one. Here’s what you’ll need to have handy for this part of the process:

A personal email address
Your state-issued identification, such as a driver’s license, or a U.S. passport
Your Social Security number
A way to receive a code for multifactor authentication, a one-time code that can be sent as a text message to your cellphone or even your landline phone
A way to take photos of your ID, such as a smartphone
A U.S. telephone number

When you click Apply for myself | Create an account on SSA’s Sign up for Medicare page, the default method goes through login.gov. You’ll enter your email and receive a link to start the process.

If you’re like a lot of people who want to handle important transactions on a computer, you’ll still need your smartphone as you go through the steps to create an account. At one point, you’ll be asked to take a photo of the front and back of your government ID and then take a selfie.

The site, which already has asked you for your mobile number to receive the verification code, switches to your smartphone to take and upload the three images. Then it returns you to your computer to finish the sign-up, which the government says will take about 20 minutes total but may take longer, depending on how much you study the legal fine print.

You also can complete the entire login.gov process on your phone.

Write down the unique password that you’ll be asked to compose. You’ll need it again before you complete the registration and can use it later to establish an online Medicare account.

If your selfie looks a lot like your official ID, you’ll be cleared immediately to start applying for Medicare.

Although the instructions ask you to wear only accessories that you also are wearing in your ID photo, the facial recognition software can figure out your face if you’re wearing clear glasses. If repeated photos don’t result in a match, you can go to a participating post office after verifying some information online and being emailed a bar code for processing. Bring your driver’s license or state ID card; passports are not accepted there.

The platform uses artificial intelligence to check your portrait against only your personal ID, not across an array of individuals, says the General Services Administration, which helped develop login.gov. You’ll receive email confirmations every step of the way: when your authentication methods are added, your identity is verified, and when you connect your account to SSA.gov.

2. Start your Medicare enrollment. If you want to take a break, you’re in the system and can sign on later or continue your work.

Before you start applying for Medicare, make sure you have this information close by:

The email address you used to establish your account
Your Social Security number
The city and state or country where you were born
Your Medicaid number and its start and end dates if you’re on this government-financed health insurance for people whose income and assets are low
The start and end dates for your most recent employment.
The start and end dates for your most recent group health plan. The start date can be approximate; sometimes insurance coverage doesn’t begin on Day 1 of a job.

You’ll be asked whether you want to sign up for Social Security benefits now, too, and whether you want Part A alone or both Part A and Part B.

After you’ve filled out the ID section, you’ll be given a reentry number that allows you to pick up where you left off. Write it down if you want to come back later.

When you arrive at the employer and insurance questions, you’ll have the option of checking a box ☐ to indicate that your employment or health insurance has not ended if you’re still working and want to sign up only for Part A. At the end of the questions, you’ll have a chance to look at and correct much of the information that you’ve just supplied.

Then you’ll have to check a box agreeing to use an electronic signature. SSA knows who you are because you’ve logged in.

Once you hit Submit Now, your application will be sent to Social Security.

3. Save your confirmation number. This number on the next screen may be more important than the ones you receive after paying bills online.

If your application gets lost in the process, this number will help show that you finished filing successfully. You’ll be able to check its status in your online Social Security account before you receive your new Medicare number in the mail.

Expect your card and Welcome to Medicare packet about two weeks after you sign up, Medicare says. The card will show the start of your Medicare coverage, which would be your birthday month if you’re in your initial enrollment period or up to six months retroactively if you waited to sign up for Part A.

If you signed up during a special enrollment or general enrollment period, coverage generally begins the month after your application is accepted.

What’s next? You’ll pick your Medicare plans

If you’re signed up for Part A alone, you can coast until the insurance at your job or your spouse’s job ends. Then you’ll be ready to sign up for Part B during an eight-month special enrollment period.

If you’ve enrolled in both Part A and Part B — like fellow enrollees who received Medicare automatically — you’ll now have to decide between original Medicare and Medicare Advantage. Then you’ll need to choose from a multitude of private plans for original Medicare’s Part D and Medigap, or among Medicare Advantage plans with a variety of prescription and provider lists.

While you wait for your Medicare card to arrive, you can do some window shopping for plans in Medicare’s Plan Finder.

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Contributing: Linda Dono, AARP

This story, originally published Dec. 8, 2022, has been updated with more guidance about online Medicare enrollment and information that kidney failure patients on Social Security disability aren’t automatically enrolled.

About the authors

Dena Bunis covered Medicare, health care, health policy and Congress. She also wrote the “Medicare Made Easy” column for the AARP Bulletin. An award-winning journalist, Bunis spent decades working for metropolitan daily newspapers, including as Washington bureau chief for the Orange County Register and as a health policy and workplace writer for Newsday.

Kimberly Lankford is a contributing writer who covers Medicare and personal finance. She wrote about insurance, Medicare, retirement and taxes for more than 20 years at Kiplinger’s Personal Finance and has written for The Washington Post and Boston Globe. She received the personal finance Best in Business award from the Society of American Business Editors and Writers and the New York State Society of CPAs’ excellence in financial journalism award for her guide to Medicare.