Approximately 7.4 million people in the United States live with an intellectual or developmental disability (IDD). According to a 2001 report from the U.S. Surgeon General, individuals with IDD face exceptional challenges to staying healthy and getting appropriate health services when they are sick. Though the nation has taken important steps in the two decades since the release of that report, people with IDD still face significant barriers that impede greater access to quality health care and meeting their health goals. These barriers include being excluded from public campaigns to promote wellness, difficulty finding health care professionals who will accept them as patients and know how to meet their specialized needs, and struggling with unwieldy payment structures designed when people with IDD often died young or spent their lives in residential institutions. To explore the challenges and opportunities for creating an optimal care system for individuals with IDD, the National Academies of Sciences, Engineering, and Medicine Board on Population Health and Public Health Practice hosted a three-part virtual public workshop, Optimizing Care Systems for People with Intellectual and Developmental Disabilities, on December 8, 10, and 14, 2021. It featured invited presentations and discussions that explored questions related to models of care, workforce, cross-discipline and cross-sector coordination, and financing and payment for care. This publication summarizes the presentations and discussions of the workshop.