I am currently employed with a company with over 20...

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I am currently employed with a company with over 20 employees and have group insurance coverage through my employer as well as Medicare part A. I know my group insurance is primary and pays first. Question: When employer insurance is the primary payer, what parts of my copay and coinsurance from the primary insurance which I am responsible for from that insurance will Medicare cover? Thank you.

Expert Answer

When Medicare is the secondary payer of medical bills (as in your case, when your large employer provides group health insurance), it "covers" those bills in the same way as it would if it were the primary payer -- it just pays less. Here's how it works. First, Medicare (Part A or Part B) determines whether the services you've received are covered at all -- meaning that they are procedures covered by Medicare and that Medicare determines that the procedures were "medically necessary" for you. Medicare makes this coverage decision independent of whether your primary employer-sponsored insurance has decided to cover the same procedure or service.

If Medicare determines that it will cover the medical service you received, Medicare then determines its "approved amount" for that service. This is the maximum amount Medicare would pay regardless of whether it is the primary or secondary payer. This Medicare-approved amount is sometimes different from the amount the insurance company approves (because insurance companies independently negotiate with medical providers regarding the amount they will pay for specific services). Medicare then sees what the employer-sponsored insurance has paid, and will pay the difference (if the service is covered at all) between what your insurance has paid and the Medicare-approved amount. If there is any amount left over, that neither the employer-sponsored insurance nor Medicare paid, you are personally responsible for it.

To learn more about this interaction between Medicare and employer-sponsored health insurance, you can take a look through Medicare's official online booklet Medicare and Other Health Benefits: Your Guide to Who Pays First.