Retiree health plans and COBRA at 65: what changes when Medicare starts

Why retiree plans usually require Part B, how COBRA ends or shifts at Medicare eligibility, and the guaranteed-issue Medigap rights when group coverage ends.

Leaving a job around 65 raises two questions: does your retiree plan still work, and what happens to COBRA?

Retiree plans

Most retiree plans assume you have Parts A and B and pay secondary to Medicare. Without Part B, the plan may pay little or nothing for doctor bills. Check the plan's rules before turning 65.

COBRA

• If you are on Medicare first and then elect COBRA, COBRA can continue, paying secondary.
• If you get COBRA first and then become eligible for Medicare, COBRA usually ends for you (dependents may keep it).
• COBRA is never active-employment coverage, so it does not protect you from the Part B penalty.

Medigap rights when group coverage ends

When an employer plan that pays after Medicare ends, you have a federal guaranteed-issue right to buy certain Medigap plans within 63 days. Washington adds broader switching rights; see the Washington rule.

Drug coverage

Get a creditable coverage letter from your employer or retiree plan; you will need it to avoid the Part D penalty if you join a drug plan later.

Questions people ask

Do retiree plans require Part B?

Usually, because they pay after Medicare.

Does COBRA prevent the Part B penalty?

No.

What happens to COBRA when I get Medicare?

It usually ends for you if Medicare came after COBRA started.

Is there a Medigap right when group coverage ends?

Yes, a 63-day guaranteed-issue right for certain plans.

Independent educational site. Not affiliated with or endorsed by the U.S. government, the federal Medicare program, or any insurance company. Figures are 2026 amounts published by CMS unless noted; check Medicare.gov for your situation.