Javascript is not enabled.

Javascript must be enabled to use this site. Please enable Javascript in your browser and try again.

Skip to content
Content starts here
Leaving Website

You are now leaving and going to a website that is not operated by AARP. A different privacy policy and terms of service will apply.

Section 5: ready to enroll 

How to Sign Up During a Special Enrollment Period

If you delayed signing up for Medicare because you or your spouse was working, you have another chance to enroll 






• 11 steps to enroll online in Part B

• Other ways to sign up

In certain situations, you can sign up for Parts B and D outside of your initial enrollment period, without having to pay a late enrollment penalty. These are called special enrollment periods (SEP).


For instance, if you or your spouse is still working and you have health insurance through either of your employers, you might decide to sign up for premium-free Part A hospital coverage only. You can delay enrolling in Part B doctor and outpatient services coverage and hold off on choosing a Part D prescription drug plan because of your employer coverage. But when that health insurance ends, either because of retirement or another reason, you’ll need to sign up for Part B — and perhaps make your choices about Medigap, Part D or Medicare Advantage.


For Part B, you’ll need to sign up before your employer coverage ends or within eight months of losing your job-based coverage to avoid a late enrollment penalty. Keep in mind that you have a 6-month Medigap open enrollment period, when Medigap insurers can’t reject you because of preexisting conditions. This begins the first day of the month you have Part B when you’re 65 or older.


For Part D, you have a shorter special enrollment period — two months after the month that your previous prescription drug coverage ends. The end of creditable coverage can happen for several reasons, such as:


• Either you or your spouse with employer coverage retires and loses that coverage.

• Your retiree drug plan ends.

• You move out of your plan’s service area.


You can decide to buy a Part D plan to cover prescriptions or enroll in a Medicare Advantage plan that includes drug coverage.

We’ll tell you more about signing up for a Part D plan — which is the same process during initial, special or open enrollment periods — in How to Enroll in a Part D Plan.




If you need to enroll in Part B during a special enrollment period, visit the Social Security Administration (SSA) website. To complete the form, you’ll need your Medicare number, documentation of your spouse’s or your health insurance and an email address.

1. At the bottom of the first page, check a box indicating that you understand the agency’s policies. Click Start application and you’ll link to the application page.

2. Scroll down and fill out the application for enrollment. Provide your Medicare number, then click yes when you’re asked if you want to sign up for Part B. Type in your name, address and phone number. In the Remark field, identify the date you’d like your Part B coverage to start.

a screenshot of section A of the medicare part b online application with the section “remark” circled in red

In Section B, provide information about the employer you’re receiving health insurance from.

a screenshot of section B of the medicare part b online application with the section “employment information” circled in red

In Section C, provide information about your group health plan.

a screenshot of section C of the medicare part b only application with the section "for employer group health plans only" circled in red

In Section D, you’ll need to provide evidence of your coverage. Complete Section A of form CMS- L564 and ask your employer to complete Section B. The employer can send the form directly to the SSA or the company can send you a digital copy, which you’ll need to upload.

If your employer cannot provide evidence of your group health coverage, you’ll need to submit proof of your employment and health insurance coverage. The following documents are acceptable:

• Tax returns that show your health insurance premiums were paid.

• W-2s that show pretax medical contributions.

• Pay stubs that indicate your health insurance premiums were deducted.

• Health insurance cards that show the date your policy began.

• Explanation of benefits statement from the health plan.

• Statements or receipts that show paid health insurance premiums.

If you need to include these documents, you’ll upload them in the yellow spaces.

a screenshot of section D of the medicare part b online application with the two section click to attach employment verification fields circled in red

Once you’ve completed Section D, type in your name and click the blue Apply button. 

screenshot of where you electronically sign your name on the Medicare part B online form

Watch for a screen with a black bar at the bottom, then click the blue Click to Sign button.

a screenshot of where the click to sign button is on the medicare part b enrollment form

Enter your email address and click the Click to Sign button.

a screenshot of where to enter your email to sign the medicare part b online form

Go to your email account and look for a message from Adobe Sign. Click on the link that says Confirm my email address.

a screenshot of a social security email from sender adobe sign. Confirm my email address is circled in red in the email body

You’ll be taken to a page that confirms your e-signature was verified. Watch for a second email that confirms your application was submitted.

11. The SSA will send you a letter informing you of your application’s status. If it’s denied, you can appeal the decision by following the instructions.




If you don’t want to enroll online, print the form and mail it, fax it or bring it to your local Social Security office. Alternatively, you can fill out Form CMS-40B and have the employer who provides your health insurance complete Form CMS-L564. If the employer is unable to complete the form, you can submit the documents that show you had health insurance.

To avoid long lines, contact your local office to find out whether you can go in person or must mail your application.

To find your local office, use the Social Security Field Office Locator. If you want to mail your application, use certified mail, which provides confirmation that your document was delivered. 

Updated February 6, 2023

How to Sign Up During Your Initial Enrollment Period
How to Sign Up During the General Enrollment Period