How do I enroll in Medicare online?

You apply at ssa.gov through Social Security, not at Medicare.gov. It takes about 15 minutes. Here is what to have ready and what happens after.

Updated September 3, 2026 · 3 min read · by Gerino Alejos

Key points

You sign up for Medicare at ssa.gov, the Social Security website. Medicare.gov is for comparing plans after you have your Medicare number.
The application takes about 15 minutes and only signs you up for Part A and Part B. Drug coverage, a supplement or an Advantage plan come after your card arrives.
If you are already receiving Social Security payments, you do not apply at all. Your card comes in the mail about three months before your 65th birthday.

You enroll in Medicare online at ssa.gov, the Social Security website, not at Medicare.gov. The application takes about fifteen minutes and is straightforward. The confusing part is only where to go.

Where to apply: ssa.gov, not Medicare.gov

Enroll at ssa.gov. Social Security handles Medicare enrollment, even though the Medicare program itself is run by the Centers for Medicare and Medicaid Services (CMS). Medicare.gov is where you compare plans afterward. It is not where you sign up for Part A and Part B.

You can also call Social Security or go to the local office. If anything about your situation is unusual, going in person is worth the trip.

What to have ready

Your Social Security number.
Your date and place of birth.
If you were not born in the United States, your permanent resident card or your naturalization information.
Your employer's name and the dates you worked there, if you are signing up after 65 because coverage from a job ended.
Your bank information, if you want the Part B premium (the monthly bill for Part B) drafted from your account instead of taken out of your Social Security check.

You do not need to have chosen a plan yet. This step is only Part A, the hospital part, and Part B, the part that pays for doctor visits and outpatient care.

The Part B choice inside the application

The application will ask whether you want Part B. Think about this before you click.

Taking both A and B is the standard choice for anyone who is not covered by a job they are still working at.
Taking A only makes sense if you are still working and your employer coverage qualifies. There is one exception. If you put money into a Health Savings Account (HSA), even Part A alone stops your contributions.

See working past 65 for how to decide.

What happens after you submit

You get a confirmation number. Save it.
Social Security processes the application, usually within a few weeks.
Your red, white and blue Medicare card arrives by mail. It shows your Medicare number and your start dates for Part A and Part B.
Only then can you join a Part D drug plan, a Medicare Advantage plan or a Medigap policy, because all of them require your Medicare number.

Everything waits on the card. Nothing else can be set up until it arrives. That is one more reason to apply in the first three months of your window, not the last.

What the online application does not cover

Applying at Social Security puts you in Original Medicare, meaning Part A and Part B. It does not give you drug coverage, and it does not add dental or vision. It also does not put a limit on the 20 percent of most bills that Part B leaves to you.

Those are separate decisions you make after your card arrives, and they decide what you pay all year. Read Original Medicare versus Medicare Advantage before your card shows up, not after.

If you are already drawing Social Security

Then you do not apply at all. Enrollment in Part A and Part B is automatic, and the card arrives about three months before your 65th birthday. Watch the mail. A card thrown out with the junk mail creates a real headache.

Once your card arrives, the next step is choosing drug coverage and either a supplement or an Advantage plan. Call our McAllen office at (956) 687 3334, or enter your ZIP code in the plan pricing box on this page.

Common follow-up questions

Do I apply at Medicare.gov?

No. You enroll at ssa.gov through Social Security. Medicare.gov is for comparing plans after you have your Medicare number.

Can I enroll in a drug plan at the same time?

Not in the same application. You need the Medicare number from your card first. That is why applying early in your window matters.

Do I have to visit an office?

Not usually. Online handles most situations. Go in person if you are signing up late, working out timing with coverage from a job, or appealing an IRMAA decision (an income based surcharge on your premium).

Want this looked at properly?

We are an independent agency in McAllen serving Hidalgo, Cameron and Starr counties. There is no obligation to talk it through.

Call (956) 687 3334

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