Question: How do leg amputation codes differ from each other? Minnesota Subscriber Answer: Technique differentiates leg amputation codes (27880-27882). The most commonly performed procedure is coded as 27880 (Amputation, leg, through tibia and fibula), usually termed a below knee amputation (BKA). During this procedure, the orthopedist amputates the patient's leg and closes the remaining skin flaps around the amputation site. You should report 27881 instead (... with immediate fitting technique including application of first cast) if the orthopedist fits a cast in preparation for an artificial leg placement. Choose 27882 (... open, circular [guillotine]) when the surgeon amputates the leg but doesn't leave a skin flap.