The National School Lunch Program and the School Breakfast Program, administered by the Food and Nutrition Service of the U.S. Department of Agriculture (USDA), are key components of the nation’s food security safety net, providing free or low-cost meals to millions of school-age children each day. Under the most commonly adopted provisions, USDA reimburses districts for meals served on the basis of data collected in a base year, during which applications are taken. After 3 or 4 years, applications must be taken again to establish new base-year data, unless the district provides evidence that local conditions have not changed. A special provision that does not require applications to be taken every few years would reduce burden, be more attractive to school districts, and potentially increase student participation by expanding access to free meals. To support the development of such a provision, the Food and Nutrition Service asked the National Academies to study the technical and operational issues that arise in using data from the American Community Survey (ACS)–a new continuous survey replacing the long-form survey of the decennial census–to obtain estimates of students who are eligible for free and reduced-price meals for schools and school districts. Such estimates would be used to develop claiming percentages that, if sufficiently accurate, would determine federal reimbursements to districts for the schools that provide free meals to all students under a new special provision that eliminates the base-year requirements of current provisions.