I am currently taking a physical therapy course to learn more in the field I am currently working in. One thing has me confused. Incident to rules state that "Auxiliary staff may perform services ordered where such delegation is permitted under the doctor’s license, provided that the physician is in the office suite providing supervision. The physician does not need to be in the room, but they must be in the office and immediately available to intervene if needed." For physical therapy the rules of incident to are different "For physical and occupational therapists, the rule Is slightly different. Where permitted by their licensure rules, certified assistants can provide direct patient care under the supervision of a licensed PT/OT pursuant to a plan of care developed by the physical or occupational therapist and approved by a medical physician." (Evaluation and Management Coding for Physical Medicine and Rehabilitation, published by AAPC 2020) My question is: Under Incident To rules if a PTA is performing a service under the direction of a PT (PT evaluated and the patient is coming back in for a follow up visit and is seeing the PTA) does the PT have to be in the office at the time of the visit when seeing the PTA?