As the population of the United States grows increasingly diverse, health care disparities become vital to understand and mitigate. The ethical and financial implications of how groups of Americans gain access to health care have evolved into some of today's most challenging socioeconomic problems. Educators in radiology are just beginning to tackle the concepts of health care disparities, unconscious bias, and cultural competency.; In July 2017, the Accreditation Council for Graduate Medical Education required that all trainees and teaching faculty of accredited training programs receive training and experience in new areas of quality improvement to include an understanding of health care disparities as part of the core competencies. To our knowledge, there is no centralized curriculum regarding health care disparities for radiology residents and fellows. Many programs, in fact, have yet to introduce the concept to their trainees, who may have difficulty recognizing that this is even a problem affecting radiology. This manuscript serves as a primer for radiology trainees on health care disparities, with the goal of defining major concepts and providing examples of how variable access to radiological care can have substantial impact on patient outcomes. (C) 2018 Elsevier Inc. All rights reserved.