Can mandating or encouraging Medicaid expansions at the national level increase access to prenatal care and improve birth outcomes? What implementation policies are useful to help achieve these goals? This study, conducted by the Urban Institute, evaluated the impact of the Medicaid eligibility expansions embodied in OBRA 1986, OBRA 1987, the Medicare Catastrophic Coverage Act of 1988, and OBRA 1989 on prenatal care use and birth outcomes by conducting three analyses: 1) multivariate analysis of the impact on race-specific prenatal care use, birth weight, neonatal mortality, and neonatal intensive care in all 50 states using national aggregate data and phone survey data; 2) multivariate analysis using Tape-to-Tape Medicaid data from four states to assess the impact on the number of Medicaid-covered deliveries and the timeliness of Medicaid coverage; and 3) case studies of how the implementation of the expansions has affected prenatal care use and birth outcomes.