In which scenario is Medicare considered the primary payer?

Medicare is considered the primary payer in a scenario where a patient is over 65 and has a Group Health Plan (GHP) through a large employer. This is because when an individual is eligible for Medicare and also has coverage through a GHP, the size of the employer's group health plan matters. For individuals over 65, Medicare becomes the primary payer if the employer has less than 20 employees. However, if the employer's plan has 20 or more employees, then the GHP is usually the primary payer. It's important to understand that Medicare typically acts as a secondary payer in cases where individuals have other qualifying health insurance, especially employer-based coverage.

In the context of the other scenarios:

• If a patient is under 65 and has private insurance, Medicare would not be the primary payer since the individual is not of Medicare age, and private insurance would usually take precedence.

• For Medicare patients with no other insurance, while that may seem straightforward, it's important to clarify that Medicare automatically becomes the primary payer due to the absence of insurance; thus, this scenario does not highlight the nuances of the coordination of benefits as the selected scenario does.

• Treatment in a non-hospital facility does not inherently determine whether Medicare is the