COBRA can temporarily continue an employer health plan, but Medicare does not treat COBRA as coverage based on current employment for the Part B Special Enrollment Period.

That distinction can create a serious timing problem if someone waits until COBRA ends before applying for Medicare.

Why COBRA and active employer coverage are different

Coverage through your or your spouse’s current employment may allow you to delay Part B. COBRA continues a former employer plan after employment ends, so it does not pause or restart the Part B enrollment clock.

The eight-month Part B window

Your Part B Special Enrollment Period generally lasts eight months after employment or group health coverage based on current employment ends, whichever happens first. Choosing COBRA does not extend it.

  • Confirm the final day of active employment
  • Confirm the final day of active-employment coverage
  • Apply before the desired Medicare effective date

Part D has a different rule

Ask whether the COBRA prescription coverage is creditable. Going 63 days or more without Part D or other creditable drug coverage may create a Part D late enrollment penalty. This is separate from the Part B eight-month window.

Coordinate before you retire

Before employment ends, compare the cost of COBRA with Medicare and verify when Part A, Part B, Medigap, Medicare Advantage or Part D should begin. Keep written proof of the employer coverage dates.

Important: This article is for educational purposes and is not a complete statement of Medicare rules. Enrollment rights, costs, benefits and plan availability can vary by situation and location. Confirm current guidance before making a coverage decision.