The modifiers for anesthesia are located in Current Procedural Terminology (CPT) manual. This was developed by the American Society of Anesthesiologist in order to help coders to distinguished between different levels of complexity of anesthesia service by the help of physical status modifiers or P modifiers for each patient. Then the coder will attached it on claim forms after the procedure code.
In addition, all anesthesia services are reported with the five-digit procedure code and the addition of a physical status modifier.