However, if the physician already delegates prescriptive authority to other APNs or PAs a primary practice site, she/he will probably prefer to maintain the current medically underserved designation for the school-based clinic. By definition, a physician can only have one primary practice site. Also, a physician is limited to delegating to no more than 3 APNs and/or PAs in a primary practice and/or alternate practice site. There is no limit to the number of APNs to whom a physician may delegate prescriptive authority in a medically underserved site and a physician may delegate at up to 3 medically underserved sites simultaneously. For more information on the physician supervisory requirements that are linked to each type of prescriptive authority site, refer to TSBME Rule §193.6 or other articles in the Prescriptive Privileges section of this Web site.