Why won't my insurance company pay for anesthesia services for my knee operation?

Out of network?: It is unlikely the anesthesia would not be covered as a service for an indicated surgery but it is possible the anesthesiologist may have been out of network or didn't accept your insurance.

Call Them: This sounds like there might have been a coding error somewhere in the bill that was sent to the insurance company. No one would believe that you have to have a knee operation without anesthesia. I would call the facility where you had the procedure and ask them to help you with the insurance company. Good luck!