If your plastic surgeon has dropped out of Medicare
and is not voluntarily not accepting Medicare, you will get nothing back. If your surgeon is a provider that chooses not to accept Medicare and then accepts you as a patient, its likely your surgeon will have to accept what Medicare reimburses him/her with your 20% co-pay. Either you're a provider or you're not...
You need to talk to your surgeon's office about this. I am not sure that Medicare will reimburse you anything. First, you don't say what you are having done. The allowable charges are specific to the procedure. Next, the charges are different in different areas of the country. I am not surprised that a non-participating provider would demand payment upfront.
Medicare breast reconstruction
The reimbursement would depend on the type of reconstruction performed. Implant based reconstruction may require two stages and reimburse less than a flap based reconstruction. Best, Dr. Yegiyants