In 2001, a seminal Institute of Medicine report, Crossing the Quality Chasm: A New Health System for the 21st Century, put forth a comprehensive strategy for improving the quality of U.S. health care. This strategy attained considerable traction within the overall U.S. health care system and subsequent attention in the mental health community as well. A new Institute of Medicine report, Improving the Quality of Health Care for Mental and Substance Use Conditions, examines the quality chasm strategy in light of the distinctive features of mental and substance use health care, including concerns about patient decision-making abilities and coercion into care, a less developed quality measurement and improvement infrastructure, lagging use of information technology and participation in the development of the National Health Information Infrastructure, greater separations in care delivery accompanied by more restrictions on sharing clinical information, a larger number of provider types licensed to diagnose and treat, more solo practice, and a differently structured marketplace. This article summarizes the Institute of Medicine's analysis of these issues and recommendations for improving mental and substance use health care and discusses the implications for psychiatric practice and related advocacy efforts of psychiatrists, psychiatric organizations, and other leaders in mental and substance use health care.