In the case of a Medicare patient under the age of 65 who is covered by their spouse's Blue Cross Blue Shield (BCBS) plan through the Federal Government, the primary payer is BCBS. This is because when an individual is under 65 and is eligible for Medicare due to a disability, Medicare typically serves as a secondary payer when there is additional primary coverage available, such as a group health plan provided by an employer or a spouse’s employer.
Since the spouse's BCBS plan is a group health insurance plan, it takes precedence as the primary payer over Medicare in this situation. As a result, any medical claims would first be submitted to the BCBS plan, and after that coverage limits are reached, or if any services are not covered, the claims can then be submitted to Medicare for secondary processing. This coordination of benefits maximizes coverage for the patient and minimizes out-of-pocket expenses.