Psychology has been recognized as a health care science and profession, and psychologists have been working clinically with medically ill patients and within organized health care settings and hospitals for decades. The potentially daunting environment of organized health care should be seen by psychology as an opportunity to further develop and expand its scope of practice. With knowledge of that environment's rules, regulations, ethics, bylaws, and traditions, the clinically competent psychologist who is first seeking to practice in hospitals should succeed alongside psychologists with busy practices who are already exclusively or occasionally within an organized health care setting or medical facility. This article reviews issues of competency, credentialing, privileges, bylaws, and practice expansion to guide psychologists toward a successful hospital practice with medically ill patients. (PsycINFO Database Record (c) 2016 APA, all rights reserved)