Mental health and substance use disorders are a serious public health problem, affecting approximately 20 percent of Americans. The two often occur together and result in significant morbidity and mortality. The Patient Protection and Affordable Care Act (ACA), passed in 2010, and the Mental Health Parity and Addiction Equity Act, passed in 2008, aim to improve the delivery of and access to treatments for mental health and substance use disorders. In this context, the Institute of Medicine (IOM) convened an expert committee to identify key steps to ensure that evidence-based, high-quality care is provided to individuals receiving mental health and substance use services. The resulting report, Psychosocial Interventions for Mental and Substance Use Disorders, details the reasons for the gap between what is known to be effective and what is currently practiced, and it offers recommendations for how best to address this gap by proposing a framework that can be used to establish standards for psychosocial interventions.