Background: The Veterans Choice Program and MISSION Act have transformed how VA delivers care by expanding Veterans’ eligibility to receive VA-funded care from community providers. The effects of this change on the quality and equity of care are unknown. Understanding these effects is critical, given the importance of these programs to VA and the complexity of managing care for Veterans across different health systems. To address this evidence gap, we will use a quasi-experimental regression discontinuity (RD) design and examine outcomes in medically and socially vulnerable subgroups to determine the impact of Choice and MISSION on quality and equity of Veterans’ health care. To further examine impacts on vulnerable groups, we will analyze disparities in ratings of community care from VA’s Survey of Healthcare Experiences of Patients (SHEP). Significance: This proposal addresses cross-cutting HSR&D research priorities, including evaluating the quality and equity of care for Veterans in the context of a key legislative priority for VA: the MISSION Act. We will examine how the effects of receiving community care, and patient experiences with community care, differ in vulnerable populations, addressing VA priorities related to equity. The project constitutes an advancement in the rigor of research while directly informing ongoing and high priority clinical initiatives within VA. Innovation and Impact: Our project is innovative because it uses an RD design to provide causal evidence about the effects of community care on the quality and equity of outpatient care and prescribing. The project is also innovative and impactful in its attention to subpopulations of socially and medically vulnerable Veterans, including analyses of disparities in community care patient experiences from national survey data. By working closely with operational partners and a Veterans Advisory Board, we will impact VA policy by translating findings into actionable recommendations to improve community care, particularly for vulnerable groups. Specific Aims: (1) Identify the effects of receiving outpatient community care through Choice and MISSION on quality and equity. (2) Identify the effects of community care on the quality and equity of prescribing. (3) Compare Veterans’ experiences with community care in vulnerable and other Veteran populations. Methodology: We will use an RD design and analyses of both administrative and VA survey data to assess the effects of Choice (all program years) and MISSION (2019-2022) on the quality and equity of Veterans’ health care. Aims 1-2 will use a quasi-experimental RD design that compares Veterans just above vs. below distance and travel time eligibility thresholds for VA community care in Choice and MISSION. We will study effects of community care use on quality overall and, to evaluate implications for equity, in vulnerable subpopulations defined by the presence of serious mental illness or substance use disorders, complex chronic cond...