Sounds like you had a cut for what's called "Usual and Customary". You need the operative report to appeal. If you gave us the exact remark codes on your EOB we can better help you. If this is a U/C cut, you can appeal it but you need the help of the surgeon to provide you with a letter and operative report. When U/C cuts happen the provider needs to show WHY the fee was higher than "usual and customary". Yes the provider can bill you for the amount over if they were non participating with your insurance. Many times patient's have no control over "WHO" renders anesthesia, that is another reason for appeal. Again, I'm only GUESSING .. need the exact reason for the payment cut/denial.