Anesthesia Coding Alert

Question: One of our new physicians checked “field avoidance” on the superbill. What exactly is field avoidance, and how should I report it? Should I use a special code or append a modifier?

Maryland Subscriber

Answer: “Field avoidance” describes when your anesthesiologist does not have direct access to the patient’s face (or airway) because of the patient’s position. That makes the procedure more complicated for the anesthesiologist, so he’s automatically able to report a minimum of five base units for the procedure.

Check your ASA Relative Value Guide for each service’s base value. Many anesthesia services that require field avoidance have a base value of five or greater, so carriers don’t usually allow additional reimbursement. But if the base value for your physician’s procedure is less than five, you can increase the base value to five and append modifier 22 (Unusual procedural services) to the procedure code. 

Example: A patient is in the prone position during a repair of his ankle tendon (27658, Repair, flexor tendon, leg; primary, without graft, each tendon). This crosses to anesthesia code 01470 (Anesthesia for procedures on nerves, muscles, tendons, and fascia of lower leg, ankle, and foot; not otherwise specified), which has three base units. The anesthesiologist can raise the procedure’s base from three to five units for field avoidance because of the patient’s position.