As a manager of a healthcare facility, a physician asks you to research a patient's insurance. They insist that the patient will need a procedure done in the next couple of months. This will be an inpatient procedure (surgery). You have a pre-operative diagnosis, and this needs to work as the principal diagnosis for the inpatient stay at this time.

Initial Post:

How does an insurance company determine if the procedure is medically necessary?
What if the physician insists on this procedure, knowing that there might be a denial?
What are several steps that could be taken to make sure the procedure is done and the patient will not end up with a huge medical bill?
Indicate at least two possible avenues toward a solution.
Please note there are several steps toward a solution, but not all will be in favor of the patient. (Please try, though)  Feel free to use Insurance examples like HMOs, PPOs, and State or Federal/Government.