Most patients will experience at least one diagnostic error in their lifetime, according to the AHRQ-sponsored report, Improving Diagnosis in Health Care, published by the National Academies of Medicine in September 2015. These errors occur in all settings of care, contribute to about 10 percent of patient deaths, and are the primary reason for medical liability claims. Substantial effort is needed to identify research priorities, including how to measure and reduce diagnostic errors, and ensure this information is integrated into practice, where it will translate meaningful benefits for patients. This interactive meeting will explore the state of the science of diagnosis in health care and discuss ways AHRQ and other stakeholders can contribute to a collaborative approach to improving diagnostic performance, as well as identify the research and evidence, tools and training, and data and measures that are needed to improve diagnostic performance.