The organizational context in which nursing care is delivered plays a key role in health outcomes for patients. Through our NINR-sponsored program of research, continually funded since inception, we have produced vital information from large and representative samples of organizations (e.g., hospitals, nursing homes, primary care practices) on the impact of the context of nursing care on patient outcomes, health disparities, and nurse well-being. The modifiable features of interest include ensuring sufficient nurse staffing and resources, investing in nurse education, trusting nurses' autonomy to make informed clinical decisions and act, fostering interprofessional teamwork and respect, and involving frontline nurses in policy and decision-making. We conducted large-scale surveys of nurses in 1999, 2006, 2016, 2020, and 2021, aggregating their responses to produce organization-level nursing measures, as well as indicators of nurse outcomes (e.g., burnout) that we link with clinical outcomes data from patients in the same organizations. The majority of the work was cross- sectional, and while suggestive, falls short of providing the confidence needed to translate evidence into major policy and practice reforms. Our last renewal application enlarged the measurement and analytic frame to longitudinal analyses of organizational changes and outcomes at two points in time in 4 states. In this renewal, we will significantly extend and expand this work to enable replication of our data collection effort twice within the study period in 7 states (CA, FL, IL, NJ, NM, NY, PA), creating a unique panel dataset of organizations, the nurses working there, and the patients they care for, going as far back as 1999. We leverage a new partnership to substantially reduce the cost of data collection and add states that allow for new questions about the differential impact of nursing changes for various populations. The design emphasizes evaluation of factors inducing change in nursing practice, distinguishing the impact of the active and intentional, e.g., Magnet recognition, policies like staffing ratios, from the environmental and historical, e.g., COVID-19 pandemic, hospital consolidation trends, on outcomes for patients of all ages, risk factors, and demographics. Our aims are: 1) to determine whether there are sustainable effects of organizational change on nursing practice and associated patient outcomes and cost across a range of patient populations and settings; 2) to determine whether organizational nursing changes over time diminish health disparities and if the changes and their effects differ in minority-serving and/or safety-net organizations; and 3) to examine if nursing-related policy interventions (e.g., nurse-to-patient ratios [CA], staffing committees [NY]) and organizational innovations (e.g., Magnet/Pathway) aimed at improving outcomes through work environment reform had a sustained impact over time and in the face of challenges like COVID-19. The...