Systems and methods for evaluating healthcare claim transactions for Medicare eligibility are described. A healthcare claim transaction designating a payor other than a Medicare Part B payor may be received from a healthcare provider computer, and a product or service associated with the transaction may be identified as a product or service that is eligible for Medicare Part B coverage. Based at least in part on the identification, a determination may be made as to whether a patient associated with the transaction is eligible for Medicare Part B coverage. The transaction may be routed to a claims processor computer if it is determined that the patient is not eligible for Medicare Part B coverage. However, if it is determined that the patient is eligible for Medicare Part B coverage, then a message indicating that the transaction is rejected may be communicated to the healthcare provider computer.