Question: Our ob-gyn injected Alpha Interferon, which the patient supplied, into six sites of her vulva. Is there a procedure code for this or is it just an injection? Alabama Subscriber Answer: You have not stated a reason for the injections, and this information may change the coding advice that follows. Alpha Interferon is a chemotherapeutic agent used to limit the growth of malignant cells. If the physician injected the drug subcutaneously or intramuscularly, you should bill 96400 (Chemotherapy administration, subcutaneous or intramuscular, with or without local anesthesia). This code includes preparation of the agent to be administered. If the ob-gyn injected the Alpha Interferon into multiple lesions, you should use 96405 (Chemotherapy administration, intralesional; up to and including 7 lesions) if he or she injected one to seven lesions. Or if the doctor injected more than seven lesions, you would use 96406 ( more than 7 lesions). The payer, however, would expect to see a cancer diagnosis with these injection codes. If the purpose was other than limiting the growth of malignant cells, you may have to look at other coding options, such as trigger point injections into the muscle (20552, Injection[s]; single or multiple trigger point[s], one or two muscle[s]; or 20553, single or multiple trigger point[s], three or more muscles) or the regular injection code (90782, Therapeutic, prophylactic or diagnostic injection [specify material injected]; subcutaneous or intramuscular) using the number of injections sites as the quantity on the CMS 1500 form.