CMS L564 Form Federal Retiree: How to Prove Employer Coverage for Medicare Part B

Why CMS-L564 Matters for Federal Retirees

When federal retirees decide to enroll in Medicare Part B after age 65, they need to prove they had creditable employer-based coverage during the gap between their Initial Enrollment Period and their enrollment date. Without proof, Medicare charges the late enrollment penalty: 10% of the standard Part B premium for each full 12-month period you could have been enrolled but weren't.

For a federal retiree who delayed Part B by five years, that penalty would add about $101/month to the standard $202.90 premium — permanently. CMS-L564 (Request for Employment Information) is the form that prevents this.

What CMS-L564 Proves

The form documents that you had group health plan coverage based on current employment (or, for retirees, based on former employment that provides ongoing creditable coverage). For federal retirees, FEHB is creditable coverage — it meets or exceeds Medicare Part B standards — so as long as your FEHB enrollment was continuous, CMS-L564 confirms you don't owe a late penalty.

CMS-L564 is paired with CMS-40B (Application for Enrollment in Medicare Part B). You file both together when requesting a Special Enrollment Period (SEP) to enroll in Part B outside the standard General Enrollment Period.

Who Needs to File CMS-L564

FEHB retirees enrolling in Part B after 65. If you skipped Part B at 65 because FEHB was sufficient and now want to add Medicare (for cost savings through coordination or because you're considering a plan that requires it), you need L564 to access the SEP.

Former federal employees with FEHB coverage gaps. If you separated from federal service, lost FEHB, and are now enrolling in Part B more than 8 months after your coverage ended, L564 alone won't help — the SEP is only available within 8 months of losing employer coverage. After that window, you'd need to wait for the General Enrollment Period (January 1 – March 31, with coverage starting July 1) and may face the late penalty for the uncovered period.

PSHB postal retirees typically don't need L564. Since PSHB requires Medicare Part B enrollment to maintain coverage, most postal retirees enroll during their Initial Enrollment Period and never need a SEP. The form only becomes relevant if a PSHB retiree somehow missed mandatory enrollment and is enrolling late.

How to Get CMS-L564 Completed

The form has two sections:

Section A: Completed by You

Your name, Medicare number (or Social Security number), date of birth, and the dates you're requesting coverage documentation for. List the period from when you turned 65 (or first became eligible for Part B) through the present.

Section B: Completed by Your Employer or Plan Administrator

This is where federal retirees face a procedural question: who fills out Section B?

If you're currently enrolled in FEHB as a retiree: Contact your FEHB plan carrier (Blue Cross Blue Shield, GEHA, etc.) and request they complete Section B. Most major carriers have a process for this — call the member services number on your insurance card and ask for "CMS-L564 employer coverage verification."

If OPM is your de facto employer for coverage purposes: Some retirees contact OPM's Retirement Services division to complete Section B, since OPM administers your FEHB enrollment post-retirement. OPM can verify the dates of your FEHB enrollment.

If you recently separated and HR is still accessible: Your former agency's HR office can complete Section B documenting your coverage dates during active employment.

The required information in Section B is straightforward: the name of the group health plan, the dates of coverage, and whether the coverage was based on current employment. For retirees, the "based on current employment" question refers to the original employment relationship that established the coverage — your federal career.

Filing CMS-L564 and CMS-40B Together

Once Section B is completed, submit both CMS-L564 and CMS-40B to your local Social Security office. You can:

1. Apply online at ssa.gov (Medicare enrollment section) and upload the completed L564
2. Visit your local SSA office with both forms in hand
3. Mail both forms to your local SSA office

Processing typically takes 4–8 weeks. Your Part B effective date depends on when you file:

• File during months 1–7 of losing employer coverage: Coverage starts the first of the month after enrollment
• File during month 8: Coverage starts the first of the month after the month you file

The 8-Month SEP Window

The Special Enrollment Period for Part B lasts 8 months from the date you lose employer coverage. For federal retirees who are keeping FEHB, this creates an unusual situation: your employer coverage never actually ends. FEHB continues into retirement, so technically your 8-month window never starts.

This is the key advantage for FEHB retirees. You can enroll in Part B at any time — there's no deadline pressure as long as FEHB remains active. The L564 form simply documents this continuous coverage to waive the late penalty.

If you cancel FEHB, the 8-month clock starts on your cancellation date. After 8 months without Part B enrollment, you lose the SEP and must wait for General Enrollment.

Avoiding Common Delays

• Get L564 completed before you need it. If you're considering Part B enrollment in the next 6 months, start the paperwork now. Carrier response times vary.
• Keep copies of your FEHB enrollment records. Annual Open Season confirmations, plan brochures with your enrollment code, and SF 2809 copies all support your coverage claim if L564 processing hits a snag.
• Don't confuse CMS-L564 with CMS-40B. L564 proves coverage; 40B is the actual enrollment application. You need both.

The Federal Retirement Countdown Checklist integrates Medicare enrollment decisions into the 12-month pre-retirement timeline, including when to request L564 and how to coordinate the Part B enrollment date with your FEHB plan's Medicare coordination benefits.