with child health. The NCS Program Office also provided public forums for input on a variety of initiatives. Congressional Mandate The "President's Task Force on Health Risks and Safety Risks to Children" recommended this federal initiative in 1999, after which Congress passed the Children's Health Act of 2000 (Title X, Section 1004). The Act charged NICHD to: plan, develop, and implement a prospective cohort study, from birth to adulthood, to evaluate the effects of both chronic and intermittent exposures on child health and human development; and investigate basic mechanisms of developmental disorders and environmental factors, both risk and protective, that influence health and developmental processes. The Act required this NCS to: incorporate behavioral, emotional, educational, and contextual consequences to enable a complete assessment of the physical, chemical, biological, and psychosocial environmental influences on children's well-being; gather data on environmental influences and outcomes on diverse populations of children, which may include the consideration of prenatal exposures; and consider health disparities among children, which may include the consideration of prenatal exposures Objective The NCS was designed to examine the effects of the environment—broadly defined to include factors such as air, water, diet, sound, family dynamics, community, and cultural influences— and genetics on the growth, development, and health of children across the United States. The NCS was designed to follow approximately 100,000 children, some from before birth, through age 21 years. The NCS planned to collect comprehensive information to: contribute to improving the health and well-being of all children deepen our understanding of the contribution of various factors to a range of health and disease outcomes understand factors that lead to health disparities. With this broad perspective, the NCS was designed to contribute to the implementation of health equity, where each individual has an opportunity to realize their health potential. Discontinued The NCS was in its Vanguard, or pilot phase, which was designed to assess the feasibility, acceptability, cost, and utility of Study scientific output, logistics, and operations prior to initiating the Main Study. The Vanguard Study enrolled about 5,000 children in 40 counties across the United States. General recruitment was completed in July 2013. On December 12, 2014, the National Children's Study closed, after an expert review committee advised the NIH Director that moving forward with the larger Main Study would not be the best way to add to the understanding of how environmental and genetic factors influence child health and development.