That might be the primary obstacle to getting doctors to work for a salary. It may well the the "legal impediments" that the doctors on the CNN show were referring to.

It can be done, but it would take fairly large groups of doctors to organize a combined practice, taking all the insurance payments into a central pool and then paying the doctor-members a salary. If I understand correctly, the way the Mayo Clinic and the Cleveland Clinic work is that they provide the service and hand the patient the bill. The patient pays the bill and collects what he can from his insurance company and/or Medicare. It seems to me that's the only way the economics of a "salaried system" might work, unless all the doctors agreed to take a pretty significant cut in income when they went to a salary. That may be in the offing, as well. My understanding is that U.S. doctors have income levels that may be double what they are in countries with nationalized medicine.