To be able to write a prescription, a clinical psychologist must practice in a state that permits them to do so, and must either have a master’s degree in psychopharmacology or have completed the required advanced training program. According to the American Psychological Association (APA), five states currently permit psychologists to write prescriptions: Idaho, New Mexico, Illinois, Iowa and Louisiana. Many psychologists who are not able to write prescriptions work in partnership with psychiatrists, pediatricians or primary care doctors to help their patients who need medication.