Question: I am being instructed to code Z51.12 for a patient seen in our infusion clinic for a Prolia (denosumab) injection, which is accompanied by a provider’s diagnosis of age-related osteoporosis (M81.0). Is the encounter code for this visit correct? AAPC Forum Participant Answer: Even though Prolia can be used to treat patients with bone cancer, in this case, the infusion is being linked to a diagnosis of age-related osteoporosis, coded to M81.0 (Age-related osteoporosis without current pathological fracture). Because of that, you cannot use Z51.12 (Encounter for antineoplastic immunotherapy) as a code to document this encounter. Why? The Excludes2 instructional note accompanying Z51.1- (Encounter for antineoplastic chemotherapy and immunotherapy) tells you to “code to condition” any “encounter for chemotherapy and immunotherapy for nonneoplastic condition.” While an Excludes2 note instructs you that the Excludes2 condition is medically related to the main condition being treated, an Excludes2 condition can also occur independently of that condition. It is separately reportable under a different ICD-10-CM code and not included in the ICD-10-CM code or group under which the Excludes2 note appears. That means if the patient is receiving the Prolia infusion for both osteoporosis and bone cancer, you would report the osteoporosis diagnosis along with the cancer diagnosis and the diagnosis code for the immunotherapy infusion encounter. However, as that is not the case in the encounter as you report it, you would just code to osteoporosis — the only condition being treated at this visit. Bruce Pegg, BA, MA, CPC, CFPC, Managing Editor, AAPC