CMS-L564 Form: Instructions, Employer Refusal, and Secondary Evidence

What the CMS-L564 Does and Why You Need It

Form CMS-L564 — officially titled "Request for Employment Information" — is the document used to verify that you had employer-sponsored health coverage based on current active employment for Special Enrollment Period eligibility. If an employer will not complete it, the Social Security Administration can consider a self-completed form with secondary evidence instead.

You need this form whenever you're enrolling in Medicare Part B after delaying enrollment because you (or your spouse) had coverage through an employer with 20 or more employees. It gets filed alongside Form CMS-40B, the actual Part B enrollment application.

Section-by-Section Breakdown

The CMS-L564 has two parts, and who fills out each section matters.

Section A — You complete this. It asks for your name, Medicare claim number (from your red, white, and blue card), and the dates your group health plan coverage began and ended. If the coverage is still active, write "present" as the end date.

Section B — Your employer completes this. The employer's HR department or benefits administrator fills in the company name, the group health plan number, the dates of your active employment, and confirms that the coverage was based on current active employment. An authorized representative signs and dates it.

If you had multiple employers since turning 65, you need a separate CMS-L564 from each one. Every gap between employers needs documentation showing you maintained continuous coverage.

When Your Employer Refuses to Sign

This happens more often than CMS probably anticipated. Companies get acquired, HR departments get restructured, or a benefits administrator simply doesn't want to deal with a form they've never seen before. Here's the process when Section B stays blank:

Step 1: Put the request in writing. Send a formal letter (email works, but keep a copy) to your employer's HR department requesting they complete Section B of Form CMS-L564. Date it and keep proof of delivery.

Step 2: Follow up and keep a record. Keep a copy of your request and any response, then proceed with secondary evidence if the employer does not respond.

Step 3: Self-certify with secondary evidence. If the employer doesn't respond or explicitly refuses, you can submit the CMS-L564 with only Section A completed, along with alternative documentation proving your coverage. The SSA accepts:

• W-2 forms showing health insurance premium deductions (Box 12, Code DD shows employer-sponsored health coverage cost)
• Pay stubs with health insurance premium deductions clearly visible
• Tax returns documenting premiums paid
• Health insurance cards showing your name, the plan name, and effective dates
• COBRA election notices (these prove the coverage existed, even though COBRA itself doesn't count as active employment coverage)
• Benefits enrollment confirmations or annual open enrollment letters from the employer

Include a written statement explaining that you attempted to get the employer's certification and describing why it wasn't possible.

When the Employer Is Out of Business

Closed companies can't sign forms. But the SSA has seen this before, and the secondary evidence path was specifically designed for this situation.

Gather every piece of documentation you have: old insurance cards, W-2s, pay stubs, benefits handbooks, letters from the company about health coverage. The more overlap between documents, the stronger your case. If the company was acquired, contact the acquiring company — they often inherited the employee records and can complete Section B.

State departments of labor sometimes maintain records of employer-sponsored health plans that can serve as additional verification.

Filing the CMS-L564

Submit the completed CMS-L564 along with your CMS-40B application to your local Social Security office. You can file by:

• Mail to your local SSA office
• Fax (call your local office for the fax number)
• In person at your local SSA office (bring originals and copies)
• Online upload through your my Social Security account at ssa.gov

Pro tip: in the "Remarks" section of your CMS-40B, write "I want Part B coverage to begin [MM/YY]" with your preferred start date. This prevents SSA from defaulting to a later effective date.

Common Mistakes That Delay Processing

Leaving dates vague. The SSA needs exact months and years for coverage start and end dates. "About three years" gets your form kicked back.

Using COBRA dates as active employment dates. COBRA coverage runs after active employment ends. If you list COBRA months as employment months, the SSA will catch the discrepancy and may deny your SEP.

Forgetting the CMS-40B. The CMS-L564 proves your eligibility — the CMS-40B is the actual enrollment application. Without both, nothing happens.

Missing the 8-month window. Your Special Enrollment Period runs for 8 months from the date your employer coverage or active employment ended, whichever comes first. File the CMS-L564 and CMS-40B well before that window closes. If you miss it, you'll wait until the General Enrollment Period (January through March) and face lifetime penalties.

What Happens After You File

The SSA reviews your CMS-L564 to confirm your SEP eligibility. If everything checks out, they process your Part B enrollment with the effective date you requested. If they need more documentation, they'll contact you — which is why including thorough secondary evidence up front saves weeks of back-and-forth.

If your SEP is denied, you have the right to appeal by filing Form SSA-561-U2 (Request for Reconsideration) within 60 days of the decision.

The Medicare Late-Enrollment Penalties and Special Enrollment guide includes a complete CMS-L564 packet with pre-written employer request letters, a secondary evidence checklist, and a self-certification template for when employers won't cooperate.

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