Medicare has been playing a shell game with reimbursements for decades. They cut the base rate for an office visit or hospital stay to below the cost of the actual service, but allow for separate charges for various things that make up the difference so that doctors don't just stop accepting Medicare in mass. That's why you get billed $37 dollars for aspirin, $15 for drug administration, $50 for IV placement, $10/bag for saline drips, $75 for vitals checks, etc. That way the hospital can make up the money lost from the actual visit charge, this also requires more administration overhead, to both keep track of all the additional charges, and to make changes as the rules change.