A physician assistant (PA) is a person who is licensed to perform healthcare tasks under the supervision of a physician. A physician may delegate a variety of healthcare tasks to a physician assistant such as obtaining patient histories, performing physical evaluations, ordering and performing diagnostic and therapeutic procedures, formulating a diagnostic impression, developing and implementing a treatment plan, and monitoring the effectiveness of therapeutic interventions. PAs may also assist in surgery, offer counseling and education to meet patient needs, make appropriate referrals, prescribe controlled substances, perform minor surgery and perform other nonsurgical healthcare tasks. The Arizona Regulatory Board of Physician Assistants licenses and regulates PAs.