Anesthesia Coding Alert

Question: What is the correct way to code for field avoidance? Should certain codes and/or modifiers be used?

Tennessee Subscriber  
Answer: There is not a specific code or modifier to report procedures using field avoidance, so the billing method depends on the base units (BUs). For example, if the procedure has a BU of less than five (such as 00126, Anesthesia for procedures on external, middle, and inner ear including biopsy; tympanotomy, or 00322, Anesthesia for all procedures on esophagus, thyroid, larynx, trachea and lymphatic system of neck; needle biopsy of thyroid), increase the units charged to five. If the BUs for the procedure are higher than five (such as 00100, Anesthesia for procedures on salivary glands, including biopsy, or 00300, Anesthesia for all procedures on the integumentary system, muscles and nerves of head, neck, and posterior trunk, not otherwise specified), many coders will report the unlisted procedure and bill the unlisted-procedure code for the field avoidance (01999, Unlisted anesthesia procedure[s]). If you increase your BUs to five, include modifier -22 (Unusual procedural services) with the claim. This shows that the procedure was a special circumstance that justified more base units.