Is Medicare automatically primary?


Editorial team Published on

Medicare is primary in most cases, but it depends on whether you have other health coverage like an employer plan, Medicaid, or retiree insurance.

To see official rules and details, you can visit the Medicare Coordination of Benefits page.

When Medicare is Primary

Medicare pays first when it is your only health coverage. It also acts as the primary payer in these common situations:

  • Small employer plans: You have job-based insurance from an employer with fewer than 20 employees.
  • Medicaid: You have both Medicare and Medicaid (Medicaid always pays last).
  • Retiree coverage: You have health insurance from a former employer or union retirement plan.
  • COBRA: You have COBRA continuation coverage after leaving a job (if you are already enrolled in Medicare).

When Medicare is Secondary

Medicare pays second (meaning your other insurance pays first) in these situations:

  • Large employer plans: You or your spouse are actively working and have group health coverage from an employer with 20 or more employees.
  • Disability and large employers: You have Medicare due to a disability and work for an employer with 100 or more employees.
  • Workers' compensation: You have a work-related injury or illness covered by workers' compensation.
  • End-Stage Renal Disease (ESRD): For the first 30 months of your Medicare eligibility due to ESRD, a group health plan pays first.