I have been auditing chart records on a physician practice which includes massage therapy services. The practice is billing CPT 97140 with 4 units for each session and the massage therapist record indicates "4 units", but there is no documentation of start or stop times to support reporting 4 units. The physician is adamant that it is just fine to continue to report 4 units without documenting the actual time. Where can I find a resource that specifically addresses the documentation requirements for time-based codes? I'd like to share this with the physician.