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November 05, 2021 | Tags: Medicare

In previous posts, we’ve described different Medicare plans, but what if you are also covered through a group-sponsored insurance plan from your (or your spouse’s) employer? You may be wondering, “how does my Medicare plan work with my other insurance?"

To better understand how your two insurance plans work together to cover your medical expenses, it’s important to understand some basic terms.

  • Payer – A payer is just another name for each type of insurance coverage you have.
  • Primary payer – The primary payer is the insurance that pays your claims first up to the limits of its coverage.
  • Secondary payer - The secondary payer pays your claims if there are any costs the primary payer didn’t cover. The secondary payer may not pay all the uncovered costs.
  • Coordination of benefits (COB) – When there is more than one payer, the coordination of benefits rules decide which insurance pays first.

Let’s talk about when Medicare is the primary payer and when it is the secondary payer behind your group-sponsored plan. There are a lot of different variables that determine whether Medicare is the primary payer or the secondary payer. Some of these include:

  • Whether you are over or under 65 years old
  • Whether you are currently employed or are retired
  • Whether your group coverage is through your employer or your spouse’s/partner’s employer
  • Whether you are also on Medicaid
  • The number of employees your employer has


Example: Primary and Secondary Payer Coordination

You visit your doctor for a normal checkup. Your doctor’s office bills both Medicare and the group insurance you have through your employer for the visit. Your group insurance is the primary payer because you’re over 65 and your employer has more than 20 employees, so your group health plan pays whatever their standard rate for a doctor’s office visit is. Medicare is the secondary payer, so they pay whatever charges are left over. If there happens to be any amount left after both Medicare and your group insurance pay what they will cover, you may have to pay the remainder to your doctor’s office.

Medicare offers a helpful guide on that covers different situations and how Medicare works with your other insurance. You can also call the Medicare Benefits Coordination & Recovery Center (BCRC) Monday through Friday, from 8:00 a.m. to 8:00 p.m., Eastern Time, except holidays, at toll-free lines: 1-855-798-2627 (TTY/TDD: 1-855-797-2627 for the hearing and speech impaired) if you have questions about who pays first.

To learn more about Medicare, visit, check the Medical Mutual website, or like our Facebook page to see the latest updates in this series. You can also download our Understanding Medicare Guide for more details.