Helping Hands, Healthier Infants: The Effect of Medicaid Doula Coverage Mandates on Birth Outcomes

Over the last decade a wave of U.S. states began reimbursing doula services through Medicaid, hoping to improve infant health and narrow stark racial gaps in birth outcomes. I evaluate these mandates using the staggered 2021-2024 rollout, a panel of 32.1 million births from CDC WONDER (2016-2024), and a newly assembled measure of the state doula workforce drawn from the national provider registry. Identification comes from the policy's timing rather than from comparing doula users to non-users, addressing the selection problem that limits the existing observational literature. On average I find no detectable effect on low birth weight (LBW). Consistent with the heterogeneity emphasized by Peet (2022) and the maternal-health-disparities literature, however, the effect concentrates among the group at greatest risk: Black mothers, for whom LBW falls by roughly half a percentage point (about 5% of the baseline) in the states with the longest exposure, with flat pre-trends and a coherent upward shift in the birth-weight distribution. The estimate is marginal once I use inference valid for few treated clusters, and the binding constraint is statistical power: most mandates took effect in 2024-2025, at or beyond the end of the data. A two-stage least squares analysis shows that coverage roughly doubles the doula workforce (first-stage F approximately 21-35), and that the induced increase in doula supply is associated with lower Black LBW, though imprecisely. I read the results as credible early evidence that doula mandates work where they have had time to operate and where the need is greatest, rather than as a finished causal claim.