Question: Wisconsin Subscriber Answer: The Advair Diskus is an "aerosol generator" and therefore teaching someone to use one falls under 94664 (Demonstration and/or evaluation of patient utilization of an aerosol generator, nebulizer, metered dose inhaler or IPPB device). For example, a pulmonologist starts a patient with asthma (493.00, Extrinsic asthma; unspecified; or 493.20, Chronic obstructive asthma; unspecified) on Advair. A nurse then teaches the patient how to use the Diskus. You should report 99201-99215 for the office visit and 94664 without a modifier, according to CPT. Furthermore, CMS transmittal R954CP also indicates that modifier 25 (Significant, separately identifiable E/M service by the same physician on the same day of the procedure or other service) applies only to E/M services performed with procedures that carry a global fee, which 94664 does not have. But before dropping 25 from 99201-99215 with 94664, check with your major insurers. Some payers may require modifier 25 appended to the E/M when performed with 94664 or any "pulmonary" service.