Losing employer health coverage after 65

The short version

Week one: paperwork

• Get a creditable-coverage letter for your medical and drug coverage
• Get the CMS-L564 form signed by your former HR
• Confirm in writing the date your active coverage ended
• Note the date 8 months out — that's your Part B deadline

Month one: decide on Part B effective date

When you enroll in Part B during the SEP, you choose the effective date. You can backdate up to 6 months (but not before your eligibility started). Most people pick the first of the month after group coverage ends to avoid a gap.

If you've already paid for COBRA, you can still enroll Part B retroactively to when COBRA started. Talk to Social Security about your specific situation.

Part D within 63 days

The Part D window is much shorter. If your employer drug coverage was creditable, you have 63 days from when it ends to enroll in Part D (or a MAPD) without a late penalty. Confirm creditable-coverage status in writing — many small-employer drug plans aren't creditable and people don't realize it until the penalty letter arrives.

Estimate the Part D late penalty

Medigap guaranteed-issue rights

The COBRA trap

COBRA is the most common Medicare mistake we see at this stage. People assume staying on the same coverage delays the Medicare clock. It doesn't. The 8-month Part B SEP and 63-day Part D window both start when active coverage ends, not when COBRA ends.

If you're already on COBRA, enroll in Part B now. Keep COBRA for any benefits you want to maintain (often dental, vision, or family coverage). Part B should be on Medicare on time.

More on retiring after 65

If you're under 65 when you lose coverage

Marketplace coverage with subsidies based on income is usually the cheapest bridge to 65. COBRA is rarely the right choice for a long bridge — it's premium-priced for the same coverage you can often get cheaper on the Marketplace.

Frequently asked questions

How long do I have to enroll in Medicare after losing employer coverage?

Eight months for Part B (the Special Enrollment Period) and 63 days for Part D. Both clocks start when your active employment or your group coverage ends, whichever is first. COBRA does not extend either window.

Does losing employer coverage trigger Medigap rights?

Sometimes. If you had employer coverage that paid secondary to Medicare and you lose it, you get a 63-day guaranteed-issue right to specific Medigap plans (A, B, C, F, K, L, or N depending on availability). State rules can extend this further.

What if I'm laid off at 64?

You can't enroll in Medicare until you're eligible (usually 65). Options for the gap include COBRA, Marketplace coverage with subsidies based on income, a spouse's plan, or short-term coverage. None of these affect your Medicare timeline once you turn 65.

Can I delay Medicare if my new job has coverage?

Yes, if it's group coverage from an employer with 20+ employees and you're actively employed. The Part B SEP rules treat continuous active coverage as one period. If you re-enter active coverage before enrolling, the SEP pauses.

What if my spouse's job had the coverage?

The same rules apply when their coverage ends. Their employment status (or yours) triggers the SEP. If they retire or are laid off, your 8-month window starts even if you're not the one who changed jobs.