Sudden Death in the Young (SDY) is a tragic event with longstanding impact on families and communities. Although the causes of SDY are myriad, sudden unexpected infant death (SUID), sudden cardiac death and sudden unexpected death in epilepsy (SUDEP) are three examples that have inspired public health efforts at prevention. Yet fundamental gaps in knowledge about incidence, mechanisms, and risk factors for SDY limit the identification of effective prevention efforts. The Sudden Death in the Young (SDY) Case Registry is a collaboration between the National Institutes of Health (the National Heart, Lung, and Blood Institute (NHLBI) and the National Institute of Neurological Disorders and Stroke(NINDS)) and the Centers for Disease Control and Prevention (CDC). It was designed to address critical knowledge gaps in the epidemiology and causes of SDY and develop a resource for research that will enhance the evidence base to inform prevention efforts. The SDY Case Registry is the first prospective, population-based surveillance program that can comprehensively identify and gather data and DNA on cases of SDY in a large geographic area in the United States. Data can be used to determine the incidence of SUID, sudden cardiac death in the young, SUDEP and other causes of pediatric sudden death. The SDY Case Registry was first funded in 2013 and was built on the CDCs existing SUID Case Registry. The CDC leads surveillance efforts to identify 100% of cases of SDY in funded states/jurisdictions of the SDY Case Registry. To do this, they provide technical assistance to states/jurisdictions to increase case ascertainment and ensure consistent categorization of cases. NHLBI and NINDS focus on developing a resource for research on SDY by supporting collection of a comprehensive battery of phenotypic data elements and DNA samples to enable genomic analysis.