Infectious disease is no longer the biggest threat to our survival in the westernized world. Instead, human populations face diseases of slow accumulation such as diabetes, stroke, heart disease, and certain cancers. These modern diseases are caused by more than diet and exercise alone and are highly influenced by underlying inequalities that exist in Western societies. "The Impact of Social Factors on Health: A Critical Reader for the Physician Assistant" helps physician assistant students and professionals understand the importance of social factors and how they affect population health in US society. The selected readings were written by prominent physician assistant and public health scholars. The text examines social policy and how the social environment is organized around gender, race, and socioeconomic position. The reader is designed specifically to prepare more culturally competent physician assistants in an ever-changing society. Dedicated to making physician assistants fully aware of critical information needed for best practices, "The Impact of Social Factors on Health" is well suited to courses on cultural competency as well as public and preventative health and epidemiology. We encourage faculty to use these insightful chapters for key classroom discussions with their students. Dr. Darron Smith is an assistant professor in The University of Tennessee Health Sciences Center, Department of Physician Assistant Studies. With over 15 years of clinical experience helping the medically underserved, his research and scholarship now focuses on improving the social conditions that cause disease. Tasha Sabino is a practicing physician assistant with experience in acute and family medicine. She is also an adjunct faculty member in the Physician Assistant Program at Christian Brothers University in Memphis, Tennessee, and researches health inequities as they impact vulnerable populations.