Modified Project Summary/Abstract Section – CORAL Research Project Pregnant and postpartum women who use drugs are fighting to survive at the crossroads of 2 of the gravest public health crises of the 21st century US: (1) the maternal mortality epidemic, and (2) an evolving overdose epidemic. In a nation with the highest maternal mortality rate of all high-income countries, overdoses are a leading cause of preventable maternal mortality. State legislatures have been actively responding to this crisis: 44 states have enacted >1 law governing drug use in pregnancy. Some laws are punitive and seek to deter prenatal drug use through criminal sanctions (e.g., classifying drug use in pregnancy as child abuse/neglect). Others seek to expand substance use disorder (SUD) treatment for pregnant women (e.g., require that treatment programs prioritize pregnant women). Unfortunately, we know remarkably little about how these ubiquitous laws shape overdose or related health service use among pregnant/postpartum women who use drugs. In part, this silence reflects de-prioritization of maternal behavioral health issues in medicine/public health: the field of maternal health has largely ignored people with behavioral health conditions, and behavioral health has neglected pregnant/postpartum women. The scant evidence that does exist is, however, alarming. The handful of studies on punitive laws largely confirm ACOG, CDC, and SAMHSA warnings that these laws adversely affect women’s health and healthcare use. The few studies of laws seeking to increase SUD treatment opportunities for pregnant women find that they have no effects or may reduce SUD treatment use among pregnant women. Guided by two Community Advisory Boards, the proposed study applies a mixed- methods sequential explanatory “QUAN qual” design to inaugurate a line of high-impact research and action into the possible effects of select laws governing drug use in pregnancy on overdoses, SUD treatment use, and prenatal/ postnatal care use among pregnant/postpartum women. Aims 1-3 are national in scope, and analyze multiple administrative databases to trace, for the first time, the pathways through which these 3 laws might shape pregnant/ postpartum women’s overdose risk and health service use. Aim 4 will explain and enrich Aim 1-3 findings through an in-depth qualitative case study of these pathways in one Metro Area (Atlanta). Aim 5 applies evidence-based methods to support local responses in Atlanta around select intervention targets identified in Aims 1-4. The proposed project will have high impact: it will help pregnant/ postpartum women who use drugs survive the collision of the maternal mortality and overdose epidemics, by either optimizing the benefits of laws governing drug use in pregnancy or mitigating their harms.