PROJECT SUMMARY The goal of this study is to examine the effects of the generosity of Medicaid dental benefits for pregnant and postpartum women on access to preventive, routine and emergent dental care. Our central hypothesis is that low-income women in states that provide comprehensive dental benefits will have a higher likelihood of preventive and routine dental care in their pregnancy, and less likely to have emergency department visits for dental problems. In addition, low-income women in states that provide dental benefits in the year after birth will have greater utilization of preventive and routine dental care. To evaluate our hypothesis, we will examine the relationships between state-level generosity of Medicaid dental benefits for pregnant women and access and utilization of dental care during pregnancy and postpartum. We will use Pregnancy Risk Assessment and Monitoring Survey (PRAMS) data on dental care use and unmet dental needs from 2012-2019; and recently released nationally representative T-MSIS Analytic Files (TAF) from 2016-2019 that captures detailed types of dental utilization among more than 5 million pregnant women in the US. Our specific aims are: Aim 1. Examine the impact of pregnancy-related Medicaid dental benefits generosity on access to preventive dental care and unmet dental need during pregnancy using a causal difference-in-differences approach; Aim 2. Measure the association between pregnancy-related Medicaid dental benefits generosity and routine and emergent dental care use during pregnancy; Aim 3. Assess the relationships between postpartum Medicaid dental benefit generosity and routine and emergent dental care use in the year after birth. We will use a combination of descriptive and quasi-experimental approaches reinforced with several robustness checks. These rigorous and comprehensive approaches will enable us to make strong, generalizable conclusions about use of dental care during pregnancy and postpartum and the impacts of generosity and duration of Medicaid dental benefits. Our study will be the first to examine ED visits for dental problems in pregnancy and the patterns of postpartum dental care use. The knowledge generated through this research will inform decision-making and implementation of postpartum extensions of pregnancy-related Medicaid eligibility under the American Rescue Plan and provide preliminary data for a subsequent R01 that examines the effects of these extensions on maternal oral health.