What codes should I submit for the following two scenarios: (1) I scrape skin and prepare a KOH prep to look for infectious agents, and (2) I perform a vaginal examination and make two slides of vaginal contents (one with saline and one with KOH) to look for infectious agents?
In the first scenario, the appropriate CPT code would be 87220, “Tissue examination by KOH slide of samples from skin, hair, or nails for fungi or ectoparasite ova or mites (e.g., scabies).” For Medicare patients, the appropriate HCPCS code would be Q0112, “All potassium hydroxide (KOH) preparations.”In the second scenario, the appropriate CPT code would be 87210, “Smear, primary source with interpretation; wet mount for infectious agents (e.g., saline, India ink, KOH preps)”; and because you have two smears, you would need to report 87210 twice or put “2” in the units-of-service space on the claim form. For Medicare patients, the appropriate HCPCS code would be Q0111, “Wet mounts, including preparations of vaginal, cervical or skin specimens,” for the slide with saline and Q0112 for the slide with KOH. Note that if you were to put a single smear on one slide with saline on one half and KOH on the other, which is often how this is done, the CPT coding would be unaffected (except that you would code this with one unit of service instead of two). However, the Medicare coding would be more problematic in this case. Reporting both codes could imply that you did two slides instead of one, which would be a misrepresentation of your work. Reporting only one of the two codes is probably the more reasonable option.