CMS-L564 Form: How to Complete Medicare's Request for Employment Information

Form CMS-L564 helps document coverage through current employment when you apply for Part B under an employment-based Special Enrollment Period (SEP). If you do not qualify for that SEP, a Part B late enrollment penalty may apply, depending on your circumstances.

The CMS-L564, officially titled "Request for Employment Information," documents that your delay in enrolling was covered by active group health insurance. If SSA cannot verify qualifying active-employment coverage, the delay may not qualify for the Special Enrollment Period and a late enrollment penalty can apply.

What the CMS-L564 Form Does

CMS-L564 serves one purpose: it certifies that you had group health plan coverage based on current, active employment. This is the standard documentation used to support an employment-based Special Enrollment Period (SEP) — the 8-month penalty-free window that starts when your employment or group coverage ends, whichever comes first.

The form has two sections:

• Section A — You fill this out. It asks for your name and Social Security number, the employee's name and SSN if different from yours, and the employer's name and address. Coverage and employment dates go in Section B, which your employer completes.
• Section B — Your employer fills this out. The employer answers the coverage and employment questions, including the applicable coverage dates, work dates, and whether the employee is still employed, then signs and provides their title and phone number. Separate questions cover hours bank arrangements and large group health plans for disabled applicants.

How CMS-40B Works with CMS-L564

When applying through the employment-based Special Enrollment Period, submit CMS-L564 with CMS-40B (Application for Enrollment in Medicare Part B). Think of them as a matched pair:

• CMS-40B is your actual Part B enrollment application
• CMS-L564 is the proof that your delay was legitimate

Submit both to your local Social Security office by mail or fax, as the CMS-L564 instructions direct. SSA may also offer an online Part B SEP process for some applicants; check its current instructions to see if you can use it. If SSA cannot verify SEP eligibility, the requested enrollment may be delayed or a late enrollment penalty may apply.

Step-by-Step: Filling Out CMS-L564 and CMS-40B

Use this as a planning example, not an SSA filing deadline. Medicare says you can sign up while you or your spouse are still working and have job-based coverage; check current SSA instructions for the effective date that applies to your filing.

60 days before your last day of work:

1. Download both forms from CMS.gov
2. Complete Section A of CMS-L564 with your name and SSN, the employee's details if different, and the employer name and address. Leave coverage and employment dates for the employer to enter in Section B.
3. Complete CMS-40B with your Medicare claim number and put the requested Part B start date in its Remarks section
4. Send CMS-L564 to your HR department or benefits administrator

45 days before retirement:

5. Follow up with HR to ensure Section B of CMS-L564 is completed and signed by an authorized representative
6. Get the signed form back — don't let it sit in an inbox

30 days before retirement:

7. Submit both completed forms together to your local SSA field office
8. Request the Part B start month that lines up with the end of employer coverage, then confirm the effective date with SSA and the employer plan

The 8-Month SEP Window

Your Special Enrollment Period lasts up to 8 months from when active employment or job-based coverage ends, whichever happens first. If you miss it and no other Special Enrollment Period applies, you may need to wait for the General Enrollment Period (January 1 through March 31). If you enroll then, coverage generally starts the month after SSA receives your completed application, and a late enrollment penalty may apply.

The penalty math is straightforward: the standard Part B premium in 2026 is $202.90 per month. For every full 12-month period you were eligible but didn't enroll, you pay a 10% surcharge on that premium — permanently. A 2-year delay adds $40.58 per month to your premium for the rest of your life.

Common CMS-L564 Mistakes

Employer takes time to complete Section B. Start coordinating before the last month of work so HR has time to return the form. Confirm with SSA when to submit it for the effective date you need.

Confusing COBRA with active employer coverage. COBRA does not count as group coverage based on current employment. If you retired and elected COBRA, your 8-month SEP clock started when your active employment ended — not when COBRA runs out.

Submitting CMS-40B without employment evidence. The enrollment application alone does not document job-based coverage for this SEP. If the employer cannot complete CMS-L564, contact SSA about the secondary evidence it can accept.

Waiting until after retirement to start. Medicare says you can sign up while you or your spouse are still working and have job-based coverage. Ask SSA when to submit the forms for the effective date you need; submitting early does not guarantee there will be no gap.

When to Use CMS-4040 Instead

If you don't qualify for premium-free Part A (fewer than 40 work credits) and you're not eligible for Social Security retirement cash benefits, CMS-40B won't work for you. In that case, use Form CMS-4040 (Request for Enrollment in Supplementary Medical Insurance) to apply for Part B.

Get the Complete Enrollment Toolkit

The Medicare Enrollment Guide walks through all three enrollment pathways — initial, special, and general — with pre-annotated form instructions, an employer coordination timeline, and penalty calculators. It covers the exact sequence for CMS-L564, CMS-40B, and every other form you'll need for a gap-free transition.

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