Could anyone help me with the proper codes to use for drug and alcohol related services in an office setting? DX is 305.00. I need advice on the procedure code for the initial evaluation, individual sessions (>45 mins.), and for group sessions with peers. I have not billed for substance abuse before and just used the usual behavioral health codes (now 90791, 90834, and 90853) for this current claim with the DX of 305.00 (Non-Dependent Alcohol Abuse). Aetna is not recognizing services as coded as being related to substance abuse, which reduces the co-payment of $10 to $0 for the patient if the treatment is drug/alchohol related. Thanks!