A VA HSR&D-funded multi-stakeholder workgroup identified ways in which research could support the VA’s goal of addressing Veterans’ unmet social needs. The workgroup identified the siloed nature of VA, the lack of effective models for finding and connecting VA patients with non-VA social services, and insufficient evidence on the health impact of healthcare-based social needs interventions as three barriers that could be addressed by research. This mixed methods pilot study will begin to address these gaps by building partnerships between the research team, relevant VA program offices, and an organization that has been developing multi-sector networks to increase Veteran access to health and social services since 2015. Through their AmericaServes Initiative, the Institute for Veterans and Military Families (IVMF) builds coordinated networks of public and private organizations to support Veterans. Their breadth of services, wraparound care coordination approach, and military-centric focus make AmericaServes a promising collaborative for VA medical facilities to join to increase Veteran access to non-VA social services. Despite the potential benefits, preliminary analyses of AmericaServes client data and communication with IVMF, the Veterans Experience Office, and other VA program offices, indicate wide variation in whether and how VA medical facilities participate in AmericaServes Networks or similar collaboratives. The impact of such participation on Veteran health-related outcomes is also unknown. The overall objective of this research is to grow the evidence base needed to guide participation of VA medical facilities in collaboratives such as AmericaServes. As a critical first step, this project will identify how VA medical facilities currently participate in AmericaServes Networks and factors that impede or facilitate collaboration across organizations. The project will also establish link AmericaServes and VA administrative data to identify areas of opportunity for increased collaboration and lay the groundwork for determining the impact of such collaboration on Veteran health-related outcomes in future studies. The project has three specific aims. Aim 1 is to characterize the level of, as well as the barriers to and facilitators of, formal and informal participation of VA medical facilities in AmericaServes Networks. Guided by Himmelman’s Developmental Continuum of Change Strategies for inter-organizational collaboration, the team will conduct semi-structured interviews with key informants from a sample of AmericaServes Networks and VA medical facilities. Rapid qualitative analysis will be used to compare the barriers to and facilitators of different levels of participation. Aim 2 is to identify the number, percentage, and characteristics of AmericaServes clients who also receive services from VA medical facilities. AmericaServes data on all 2019 AmericaServes clients will be merged with sociodemographic and clinical data from VA administrat...