How Medicare works with other insurance

If you have Medicare and other health insurance (like from a group health plan, retiree coverage, or Medicaid), each type of coverage is called a “payer.”

The “primary payer” pays up to the limits of its coverage, then sends the rest of the balance to the “secondary payer.” If the “secondary payer” doesn’t cover the remaining balance, you may be responsible for the rest of the costs. If your group health plan or retiree coverage is the secondary payer, you may need to sign up for Medicare Part B before they’ll pay. This order of payment is called “coordination of benefits.”