Which plan would be primary if the patient has Medicare coverage and a large group health plan through a working spouse?

When determining the primary payer between Medicare and other types of insurance, the size of the employer group health plan plays a crucial role. In the case where the patient has Medicare coverage as well as a large group health plan provided through a working spouse, the large group health plan typically becomes the primary payer.

This is because, for individuals with Medicare who also have access to employer-sponsored coverage from a large group (generally defined as a plan with 20 or more employees), Medicare usually serves as the secondary payer. The large group health plan pays for most of the medical expenses first, and then Medicare may cover some of the remaining costs or specific services that are not covered by the employer plan.

Medicare supplement plans are designed to help fill gaps in original Medicare coverage; however, they do not take precedence over group health plans. Similarly, Medicaid acts as a safety net for low-income individuals and may function as the secondary payer, but it does not override the large group health plan in this scenario.