PROJECT SUMMARY/ABSTRACT Support from this Mentored Career Development Award will provide Ithan Peltan, MD, MSc the additional skills and training he needs to succeed in his goal of becoming an independent physician-scientist focused on improving early sepsis care. Dr. Peltan is a board-certified pulmonary and critical care physician at Intermountain Healthcare with a track record of research success, proven dedication to clinical investigation, and an excellent foundation in methods for high-quality clinical research. This proposal will complete Dr. Peltan’s transition to research independence via a structured career development plan that builds on his prior training and experience and leverages an environment with rich research and career development resources as well as access to granular multicenter clinical data. Specific learning objectives include (1) advanced epidemiologic and biostatistical methods; (2) implementation science and associated methodologies; and (3) the design and conduct of clinical trials. Dr. Peltan will acquire these new skills and knowledge by means of formal coursework, professional development training, and an innovative program of mentored research that will advance medical knowledge about sepsis and identify strategies to facilitate delivery of high-quality sepsis care in the emergency department. Dr. Peltan’s career development will be guided by an experienced and cohesive multidisciplinary mentorship team with expertise in critical care, emergency and prehospital research, sepsis, implementation science, clinical trials, and advanced analytic methods. Sepsis causes or complicates hospital stays for over 1 million U.S. patients every year, with mortality of 15- 20%. Early, appropriate antibiotics are critical to optimal sepsis outcomes. Many patients who present to the emergency department (ED) with sepsis, however, do not receive antibiotics within the intervals recommended by international guidelines and required under government standards. Given the barriers to accomplishing timely antibiotics using current care models, new approaches to ED sepsis care are urgently needed. The research planned for this K23 award aims to (1) validate methods to identify patients likely to have sepsis at or before ED arrival and (2) understand the unintended consequences of care systems that prioritize rapid antibiotic imitation for sepsis in order to (3) test whether redesigning ED sepsis care around multidisciplinary “Code Sepsis” teams activated on or before patient’s ED arrival could improve delivery of high-quality sepsis care. Importantly, this proposal addresses questions and develops methods applicable to care delivery for other high-risk critical illnesses. Findings from this research will provide the preliminary data for R01 or equivalent funding to support a multicenter cluster-randomized trial of the Code Sepsis protocol.