When to enroll when you retire

Handing off from work coverage to Medicare

Retiring is when all the timing rules come together. The goal is a clean handoff: your employer coverage ends and Medicare picks up with no gap and no penalty. That means lining up Part B, drug coverage, and your plan choice around your last day of work, rather than sorting it out afterward.

Get Part B timed right

Use your eight-month Part B Special Enrollment Period. File Form CMS-40B and Form CMS-L564 with Social Security, ideally a month or two before your coverage ends, so Part B starts the day after. Don’t lean on COBRA to bridge the gap — it doesn’t extend your Part B window and leaves you underinsured once you’re Medicare-eligible.

Add drug coverage and consider Medigap

If your work drug coverage was creditable, you have a two-month window to join a Part D plan after it ends. Leaving group coverage also often triggers a guaranteed-issue right to buy certain Medicare Supplement plans without any health questions — typically a 63-day window. That can be valuable if your health would otherwise make a Medigap plan hard to get or expensive.

Avoiding a coverage gap

The cleanest sequence is straightforward: tell HR your end date, get Form CMS-L564 signed, submit your Part B application, then choose between Medicare Advantage or Original Medicare paired with a Medigap and a Part D plan. Coordinate the effective dates so your coverage is continuous from your last day forward.