We are billing for in-office urine drug screening for our pain management patients. It is a cup with 10-12 drugs tested with results displayed on the cup. We are coding the screening with CPT 80305 and diagnosis code of Z13.89. The service is being denied as the diagnosis is inconsistent with the procedure. Can someone that is familiar with this service and advise what diagnosis code we should be using for the in-office urine drug screen. Also, are we are using the correct CPT code as well. Thank you for any feedback we can receive.