Anesthesia time units are calculated a special way for insurance coverage. You have a few different things to address, the first being that the Anesthesiologist was not in network (resulting in lower reimbursement, correct?) This can be appealed and in many situations, sucessfully, you will need to contact the surgeon to get a copy of the operative report. If the surgery was "elective" in nature there should have been communication prior to the surgery on what was covered and what wasn't as well as meeting / consult with anesthesiologist, normally both the surgeon, anesthesiologist will request a Pre-determination. If the surgery was elective, there's not much you can do to get the out of network covered as the carrier can say the surgery was elective and was up to you to make sure all providers were in-network. If the surgery was emergency related and/or required additional time or there were extenuating circumstances, then most likely the appeal will be successful. YOU will need the operative report no matter what. Most likely the office will help you with a letter or request for appeal as they will be wanting their balance.
Yes, these are separate bills. Facility is billed and then professional component's are billed separately (surgeon, anesthesiologist, pathology, etc) Such a racquet huh?
Do not go by the time you spent with the Anesthesiologis, as I mentioned anesthesia units are calculated for insurance purposes and not really anything you should go by, the operative report should allow for the carrier to determine if any additional benefit should be allowed either based on medical necessity and/or by overturning the out of network decision.
Good luck.. remember to follow timely filing on your appeal.. the carrier will tell you what their timely filing limit is for the appeal, most cases it's 90 days from the date on the EOB/Remittance.