Updated October 18, 2026. Quick answer: Form CMS-L564 is the Medicare Request for Employment Information. You fill in Section A, your employer fills in Section B, and the signed form goes to Social Security with your Part B enrollment request (CMS-40B). It proves that you had group health coverage through current work, which is what lets you enroll in Part B in a Special Enrollment Period.
Quick reference
| Item | As printed on the form or stated in Social Security’s Medicare booklet |
|---|---|
| What the form is | Proof of group health plan coverage based on current employment |
| Section A | Completed by the person signing up for Part B |
| Section B | Completed by the employer |
| Sent with | Form CMS-40B, to your local Social Security office |
| Gap allowed | Coverage must not have ended more than 8 months ago |
| Enrollment window after employment or coverage ends | 8 months |
| Usual age to enroll | Age 65 |
| Help | 1-800-772-1213 (TTY 1-800-325-0778) |
What the form is for
The first lines of the form give its purpose: “Use this form to show proof of group health plan coverage based on current employment so you can enroll in Medicare.” It also states the test it supports: “To enroll in Medicare through a Special Enrollment Period, you must have had group health plan coverage through your or your spouse’s current employment since the first month you were eligible for Medicare Part B. Your coverage must not have ended more than 8 months ago.”
People who qualify for Medicare because of a disability face a size test: “If you qualify for Medicare because of a disability, you must have large group health plan coverage based on your, your spouse’s or a family member’s current employment.”
Who fills in what
The split is stated on the form: “You complete Section A of this form, then ask your employer to fill out Section B.” Section A has your name and Social Security number, the employee’s name and number if different, and the employer’s name and address.
| Section B question | What the employer enters |
|---|---|
| Is or was the applicant covered under an employer group health plan? | Yes or no, with the month and year coverage started |
| Did the coverage end? | Yes or no, with the month and year it ended |
| When did the employee work for the company? | From and to dates, and whether still employed |
| Large group plan and the applicant is disabled | Every month the plan was primary payer |
| Hours bank arrangements only | Whether covered, whether hours remain in reserve and the date reserve hours ended or will be used |
| All employers | Signature, date, title and phone number of a company official |
Where it goes and the CMS-40B link
The form says “Mail or fax this completed form together with your Application for Enrollment in Medicare (CMS-40B) to your local Social Security office.” Our page on Form CMS-40B covers the enrollment request it travels with.
The form prints no deadline of its own beyond the 8 month test above. The clock that matters is the one in the enrollment window, which the Social Security booklet describes as “the eight-month period that begins the month after the employment ends or the group health coverage ends, whichever happens first”.
If your employer will not or cannot sign
The Social Security booklet covers this: “If your employer is unable to complete Section B, please complete that portion as best as you can on behalf of your employer without your employer’s signature.” You then send secondary evidence. The booklet’s list includes “Income tax returns that show health insurance premiums paid.” “Pay stubs that reflect health insurance premium deductions.” and “Health insurance cards with a policy effective date.” It also lists W-2s showing pre-tax medical contributions, explanations of benefits paid by the plan, and statements or receipts that reflect payment of health insurance premiums.
The edition read for this page is Form CMS-L564 (Revised 03/2025) as the agency served it on 2026-10-18. Check the edition printed on the copy you send, because a later edition can change the questions, the mailing instructions and the evidence asked for.
Common mistakes
- Sending CMS-L564 on its own. The form says it travels with the CMS-40B enrollment request.
- Leaving Section B for the employer without giving them the form early. Section B asks for coverage start and end dates, employment dates and a company official’s signature.
- Relying on COBRA or retiree coverage. The Social Security booklet says neither counts as current employer coverage.
- Skipping the secondary evidence when the employer cannot sign. The booklet lists the documents accepted in place of the employer’s signature.
Related: Form CMS-40B, working past 65 and Medicare, the HSA and Medicare six month lookback, and Social Security and Medicare forms.
Sources
- Form CMS-L564 (Revised 03/2025), Medicare Request for Employment Information: https://www.cms.gov/Medicare/CMS-Forms/CMS-Forms/downloads/cms-l564e.pdf
- SSA Publication 05-10043 (2026), Medicare: https://www.ssa.gov/pubs/EN-05-10043.pdf
Read from the Social Security Administration and Centers for Medicare and Medicaid Services documents linked above on October 18, 2026. General information, not legal or benefits advice. Your own facts decide the outcome, and Social Security at 1-800-772-1213 is the right place to confirm anything consequential.