Wiki incident to - If a physician is in the office

Did you ever get an answer to this question? I just had an RN call me and she would like to see if she could bill for her time as well.... MD came in and saw the patient, but the RN did the procedure
Incident to can only be used when a non-physican practictioner is performing services (NPP or PA for example). Any services that an RN performs would be billed under the supervising dr and not subject to incident to....does that make sense?