PROJECT ABSTRACT U.S. physicians are at risk for poor mental health and work-related wellbeing. Obstetrician- gynecologists (OB-GYNs) are at particularly high risk due to recent changes and uncertainty in state-level reproductive health policies. Associated changes in the work environment may lead to burnout, poor mental health, and job turnover, which could have major health consequences for OB-GYNs and their patients. Our scientific premise is that the key to improving OB- GYNs' mental health and work-related wellbeing in a shifting policy climate is to focus on the role of organizational factors in buffering the impact of policy stressors. Accordingly, there is an urgent need to (1) better understand the relationships between state policy environment, work-related stressors, and mental health and work-related wellbeing, and (2) identify organizational-level factors that support OB-GYNs' health and wellbeing. Leveraging our interdisciplinary team's expertise in workplace health and wellbeing, experience with survey methods and policy analysis, and our preliminary data, we propose a convergent mixed- methods study of OB-GYNs from across the U.S. We will administer a quantitative survey to 800-900 OB-GYNs to (1) test whether OB-GYNs' mental health, work-related wellbeing, and turnover intention vary by policy context, and (2) evaluate the nature of the relationship between policy context, work experiences, and mental health and work-related wellbeing (Aim 1). We will conduct qualitative semi-structured interviews with 80 OB-GYNs from a range of state policy climates. We will then use mixed methods to synthesize survey and interview findings about the contributions of specific organizational policies and practices to OB-GYN mental health and work-related wellbeing, within and across policy contexts (Aim 2). Finally, we will draw on Aim 1- 2 findings and solicit input from key informant interviews (n=10) to develop and disseminate organizational-level resources to support OB-GYNs' mental health and work-related wellbeing (Aim 3, r2p). We will engage an interdisciplinary expert advisory board to inform the design, analysis, and dissemination. Our long-term goal is to protect and promote the work-related wellbeing of the healthcare workforce. By generating novel data from a national sample of OB-GYNs, this study will inform evidence-based recommendations and interventions to support OB-GYN mental health and work-related wellbeing. Its impacts support NIOSH's Total Worker Health® and Healthcare Worker Mental Health Initiatives, the NORA Healthcare and Social Assistance sector, and NORA's cross-sector program in Healthy Work Design and Wellbeing.