Abstract Alcohol consumption adversely affects up to 28% of hospitalized patients and contributes to a loss of 133 million disability-adjusted life years and 5.3% of worldwide deaths each year. As alcohol use has substantial health and economic impact, much attention has been directed toward the numerous adverse health outcomes in patients with unhealthy alcohol use. Alcohol use disorder (AUD) occurs on a spectrum from mild to severe and is precipitated by binge drinking and heavy alcohol use. We and others have shown that AUD is a modifiable perioperative risk factor and is present in up to 18% of surgical patients. Despite its significant clinical impact, AUD is often overlooked in the design of perioperative care plans. Although AUD affects 9% of the US population, less than one in ten individuals with AUD receives any treatment. Barriers to treatment are multiple and include scarce care availability, limited access, and social stigma. Although anesthesiologists routinely provide guideline- concordant treatment for non-operative medical conditions such as coronary artery disease, AUD-specific care is rarely provided, even to high-risk patients. Thus, there is a compelling opportunity to integrate AUD screening and treatment into routine perioperative care. Our central hypotheses are that AUD health services initiated in the perioperative period will 1) leverage the significant resources made available to perioperative care in the US, 2) forge novel synergistic alliances between previously disconnected healthcare settings, and 3) break down barriers to access to care for health disparity populations. A multi-institutional team of anesthesiologists, biostatisticians, psychologists, and psychiatrists with expertise in AUD treatment and novel clinical trial designs will lead the Leveraging Alcohol Use Disorder Screening for Treatment in Routine Perioperative Care: AllUsCare proposal and proposes three aims: 1) Leverage our existing EHR-integrated Alcohol Use Disorders Identification Test-Concise (AUDIT-C) screening tool to increase provision of AUD-specific perioperative care, 2) Conduct a two-center prospective observational cohort study to assess patient acceptability of interventions, feasibility of outcome data collection, and optimum outcome measures for a future pragmatic trial, and 3) Optimize perioperative AUD intervention bundles most likely to be effective in a future pragmatic randomized factorial cluster trial through a health equity lens. This R34 planning grant will lay the groundwork for identifying the most effective health service intervention bundles in surgical patients at high risk for AUD. To maximize inclusion of NIH health disparity populations, we will conduct our study in two centers that serve inner-city and rural populations and will deliberately include patients aged 12 years and older. At the conclusion of AllUsCare, we will have established the research team, designed an AUD intervention bundle most likely to be effec...