The book is primarily written for health professions students and practitioners—physicians, nurses, nurse practitioners, physician assistants, pharmacists, social workers, community health workers, public health experts, and others—who will benefit from understanding the complex environment in which they work. Physicians feature prominently in the text, but in the actual world of clinical medicine, patients’ encounters with other health care providers are an essential part of their health care experience. Physicians would be unable to function without the many other members of the health care team. Patients seldom appreciate the contributions made to their well-being by public health personnel, research scientists, educators, and many other health-related professionals. We hope that the many nonphysician members of the clinical care, public health, and health professions education teams as well as students aspiring to join these teams will find the book useful. Nothing can be accomplished without the combined efforts of everyone working in the health care field.