Background: Recently, VA underwent two unprecedented disruptive changes that fundamentally altered how care is delivered to Veterans. First, the VA MISSION Act was implemented in June 2019. Arguably the biggest policy change in VA care delivery since the "Kizer revolution,” MISSION’s purpose is to improve Veteran access to care, especially for services that have traditionally been resource-limited in VA due to geographic/ temporal barriers (e.g., specialty care). While VA healthcare systems were still in the early phases of adapting to MISSION, the COVID pandemic spread rapidly across the world, resulting in a sudden and prolonged ramp- down of elective outpatient care across the entire US healthcare system. VAMCs nationwide are independently adapting to these disruptive changes in ways that directly impact Veterans’ health and experience. Significance/Impact: Currently, we know little about MISSION’s early effects on where and how Veterans access specialty care (as moderated by COVID-related disruptions), or factors influencing community care referral. We also lack a clear understanding of how individual VAMCs are responding to these disruptive forces in realigning organizational strategy/structure to optimize performance. Addressing these knowledge gaps is critical to assessing the long-term impacts of MISSION and COVID on VA specialty care delivery and helping VAMCs to tailor adaptation approaches to their local setting to optimize the health and experience of Veterans. Innovation: Expansion of VA community care under the MISSION Act represents one of the largest natural experiments in delivery transformation in any U.S. healthcare system in modern times. Thus, VA community care expansion under MISSION offers an unparalleled opportunity to study the relationship between rapid environmental change, organizational adaptation, and long-term performance. The unanticipated system "reset" caused by COVID will only amplify and accelerate the adaptation process already underway. Specific Aims: Aim 1: Examine the relationship between VAMC organizational/environmental characteristics and longitudinal performance under MISSION/post-COVID, and the extent to which facility-level organizational adaptation measurably impacts performance. Aim 2: Characterize variation in organizational adaptation by high-performing tertiary VAMCs with different organizational/environmental characteristics. Aim 3: Explore how the experience of Veterans with specialty care needs differs at high-performing VAMCs with distinct organizational adaptation approaches. Methodology: In Aim 1a, using a longitudinal pre-/post- comparison analysis, we will examine the relationship between VAMC organizational/environmental characteristics and longitudinal performance under MISSION/post-COVID, including measures of access, care coordination, and community care referral. In Aim 1b, using a difference-in-differences approach, we will leverage differences in financial incentives between VAMCs ...