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Working past 65

The 8-month SEP: leaving work without leaving a gap

When employment or group coverage ends — whichever comes first — an 8-month Special Enrollment Period opens for Part B with no penalty: file form CMS-40B plus form CMS-L564 (employer verification). Enroll before work ends and coverage can start the day after the employer plan stops, with no gap.

The window, precisely

The Part B SEP lasts 8 months, starting the month after employment ends or the month after the group coverage ends — whichever comes first. That "first" matters: keep COBRA for a year after leaving and the SEP still expired four months before COBRA did. There's no penalty for any month covered by current employment back to 65, which is what the L564 documents.

The five steps, in order

  1. Start about 90 days out. Once a retirement date firms up, begin — Part B effective dates can be coordinated so coverage begins the month after employment ends (or sooner), eliminating any gap. TFL and CHAMPVA households especially: the wraparound starts only when B does.
  2. Get CMS-L564 signed by your employer. The Request for Employment Information form proves the creditable coverage that excuses your late start. HR completes Section B; one form per employer whose coverage you're claiming since 65.
  3. File CMS-40B with Social Security. The Application for Enrollment in Part B — submit online at ssa.gov (upload the L564), by fax, or at an office. Write your requested start date on the form.
  4. Handle the drug side in parallel. Losing creditable employer drug coverage opens a 2-month window for Part D — irrelevant if VA, TFL, or CHAMPVA coverage continues, decisive if employer coverage was your only creditable drug source.
  5. Calendar the hard stop. The SEP runs 8 months from the end of employment or coverage, whichever is FIRST. Miss it and you're in General Enrollment territory: January–March signup, coverage the month after, lifelong penalty.

The veteran-specific overlay

  • TFL households: Part B's effective date is TFL's start date — sequence them to the day after the employer plan ends and the wraparound takes over without a seam. The TFL checklist covers the DEERS side.
  • CHAMPVA households: identical logic — B in place keeps CHAMPVA alive and moves it to secondary behind nothing once the employer plan exits.
  • VA-only veterans: this SEP is also your Medigap moment — the six-month guaranteed-issue window opens when this Part B takes effect, and it never reopens. Decide the Supplement question inside it, deliberately.
  • Everyone: retirement-year income drops are SSA-44 territory if IRMAA grabbed you based on a fat final working year.
One number to keep handy

Social Security: 800-772-1213. The L564/40B path is routine for them — but employer HR turnaround on the L564 is the usual bottleneck, so request it first, not last.

Ninety days out from retirement is exactly when an agent earns their keep: Part B timing, the Medigap-or-MA fork, and the wraparound handoff, sequenced in one pass.

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Frequently asked questions

What forms do I need for the Part B SEP?
CMS-40B (the Part B application) plus CMS-L564 (employment verification, completed by each employer whose coverage you're claiming). Both file together with Social Security — online, fax, or in person.
Can I enroll in Part B before my last day of work?
Yes — and you should. The SEP allows enrollment anytime while still covered by current employment, letting you set a start date that meets the employer plan's end date exactly.
Does COBRA extend my 8-month window?
No — the window runs from the end of employment or group coverage, whichever is first. COBRA is neither, so it burns SEP months while providing no protection.
Is there a penalty if I use the SEP correctly?
None — months covered by current 20+-employee employment don't count toward the Part B penalty, which is precisely what the L564 documents.
What if my employer no longer exists to sign the L564?
Social Security can accept alternative evidence of coverage — W-2s, plan documents, pay stubs showing premium deductions. Bring what you have; don't let a defunct employer stall the filing.

Related guides

The full sequenceEvery date, in order.What missing it costsThe calculator version.All the windowsWhere the SEP fits.

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