How do I apply for Medicare if I delayed past 65?

You file the Part B application together with an employer form that proves you had coverage through a job. That form is what keeps you out of a late penalty.

Updated September 3, 2026 · 4 min read · by Gerino Alejos

Key points

If you delayed Medicare because you had coverage through a job, you file two forms together, not just the standard application.
The second form, CMS-L564, is your employer confirming you had group coverage while working, and it is the proof that keeps you out of a late penalty.
You get eight months after your job coverage ends to sign up for Part B, but only two months to pick drug coverage, so do both at once.

You apply through Social Security with two forms: the Part B application and an employer form that proves you had coverage through a job. That second form is what keeps you out of a late penalty. Signing up after 65 is normal, and often the right call, when you kept working with good employer coverage.

Part B is the part of Medicare that pays for doctor visits and outpatient care, which is care you get without being admitted. See when employer insurance lets you delay. The application itself goes through Social Security.

The two forms: the Part B application and the employment verification

If you delayed because of employer coverage, the standard online application is not enough on its own. You file two forms together.

CMS-40B, the application to enroll in Part B
CMS-L564, the request for employment information, which your employer fills out

The L564 is the one that matters. Your employer signs it to confirm you had group health coverage while you were working. That is the proof that you qualify for a Special Enrollment Period, a sign up window for people who delayed for an approved reason, instead of a late penalty.

Start on the L564 early. Someone in your employer's HR or benefits office has to sign it. If the company was sold, merged or closed, finding a person who can sign takes time you may not have.

If your employer no longer exists

This happens, and it can be fixed. Social Security will accept other proof of coverage.

Pay stubs that show health insurance deductions
W-2 forms that show what the employer paid toward your health coverage
Health insurance cards with start dates
Explanation of benefits statements from the group plan, the summaries the plan mails after a claim
A letter from the insurance company confirming your coverage dates

Gather what you can and bring it to the office in person rather than mailing it. A visit settles these cases much faster.

How long your Special Enrollment Period lasts

You have eight months to sign up for Part B without a penalty. The clock starts when your job ends or when the group coverage ends, whichever comes first.

For Part D, the part of Medicare that covers prescriptions, the window is only two months. That mismatch is why people make the Part B deadline and still get a drug penalty. Handle both in the same sitting.

When your coverage starts

You can ask for Part B to start the month you file, or up to three months later. Line that date up with the end of your employer coverage. That way you have no gap, and you do not pay for a month you did not need.

The order to do it in

Ask HR for the CMS-L564 as soon as you know your retirement date, before your last day, while you can still reach them easily.
Fill out the CMS-40B yourself.
Take both to Social Security, in person if you can, and keep copies of everything.
When your Medicare number arrives, pick a Part D plan or a Medicare Advantage plan (a private plan that takes the place of Original Medicare) right away. The two month clock is already running.
If you plan to buy a supplement, a policy that pays the share of the bill Medicare leaves to you, your Medigap open enrollment runs six months from the day Part B starts. That protection does not come back.

That last point matters. Delaying Part B also delays your one guaranteed chance to buy a Medicare Supplement with no health questions. Read how the windows interact.

What to check before you file

If you put money into a Health Savings Account (HSA) while working, stop those contributions at least six months before you file. Part A, the part of Medicare that pays for hospital stays, can be backdated up to six months. Money you put in during those months counts as excess and gets taxed. See the HSA trap.

Ask for the L564 first, fill out the 40B, and file both together with your start date lined up to your last day of coverage. If you want a second set of eyes on the forms before you file, call the office or enter your ZIP code in the form on this page.

Common follow-up questions

Can I just apply online like everyone else?

You can start online. The CMS-L564 employer form still has to be turned in. Without it, Social Security has no record that your delay was protected.

My employer went out of business. Am I stuck with a penalty?

No. Social Security accepts other proof, such as pay stubs, W-2s and letters from the insurance company. Bring what you have to a local office.

How long does the whole thing take?

The application takes a few weeks to process. The real holdup is getting the employer form signed, which is why you start there.

Want this looked at properly?

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