PROJECT SUMMARY/ABSTRACT There is a critical need to identify reasons underlying the unacceptably high and rising incidence of maternal mortality in the US. Of equal concern are the deep and entrenched disparities in both maternal and infant mortality that persist despite efforts to address individual-level risk factors and improvements in obstetric care quality and technologies. Previous research endeavors have largely neglected the influence of policy, despite recent calls for adoption of a human rights approach to addressing and eliminating preventable maternal mortality. Our overall objective in this application is to determine how specific state-level policies influence incidence of maternal and infant mortality. We have established and will continue to build a state policy database for monitoring changes in state-level policies of interest over time, in conjunction with over ten years of vital records for monitoring state-level maternal and infant mortality over time. Our specific aims are (1) To identify the impact of state-level policies intended to protect women's health and improve access to health care on incidence of infant and maternal mortality (policies include expanded Medicaid income eligibility to adults earning up to 138% federal poverty level [FPL], expanded Medicaid eligibility to pregnant women earning 200% FPL, mandated prevision of reasonable accommodations to pregnant workers, and paid family leave); (2) To identify the impact of state-level policies that limit or restrict women's access to abortion on incidence of infant and maternal mortality (policies include restrictions on abortion coverage in private insurance, mandatory waiting period required between counseling and abortion, parental involvement required before minor obtains an abortion, restricting to provision of abortion service by licensed physician only); and (3) To identify differential impacts of the policies explored in Aims 1 and 2 on infant and maternal mortality by race and socioeconomic status. The research analytic design makes use of a natural experiment framework and difference-in-difference analysis, allowing for the comparison of each state to itself, before and after the policy change. This approach is robust to potential biases from unmeasured characteristics that may differ between states and influence the state's population health. Findings from this work will include empirical evidence of the causal impact of state-level policy on maternal and infant deaths, data glaringly absent from both public health prevention efforts and policymaker agendas. Findings will also include evidence of the role state-level policies may play in perpetuating deep racial and socioeconomic inequities in mortality.