Background: Every day, hospitals across the United States (US) and Veterans Health Administration (VHA) discharge patients with vascular access devices for outpatient parenteral antimicrobial therapy (OPAT). OPAT has advantages but it is not risk-free and can result in adverse events and hospital readmissions. A high degree of commitment and task performance by patients and caregivers is also required. A 2020 VHA Antimicrobial Stewardship survey found variability in who monitors OPAT patients and that most facilities use outside contract services, which may make it difficult to coordinate care across settings. OPAT is a vital part of Veteran care, yet we know very little about how it is managed across VHA or the challenges Veterans and their caregivers face while receiving at-home therapy. Significance: This research will advance knowledge and improve care delivery by addressing VHA and research clinical and methods priorities related to quality and safety, the use of cross-cutting methods and real-world impact. This work is also aligned with VA strategic goals and core principles, including providing Veterans with care in their homes when needed and the required training and resources for their caregivers. This research will advance knowledge and lead to improvements in quality and safety, a VHA clinical priority, by identifying and deploying strategies to ensure safe and effective OPAT delivery for Veterans. Innovation & Impact: This study is the first comprehensive assessment of OPAT delivery in VHA. Findings will lead to improvements in OPAT delivery and provide knowledge for improving home infusion therapy more broadly. Focusing on the patient journey, we will highlight the interactions across different socio-organizational contexts, providing a more complete view of care delivery. Innovative methods that actively engage Veterans, caregivers and clinical providers are used throughout the research process. We will also use a collaborative co-design approach to bring stakeholders together to develop interventions that are more acceptable and feasible to implement. Methods that could be used to address other care delivery challenges. Specific Aims: Aim 1: Assess how OPAT is delivered by VHA Medical Centers, through semi-structured interviews with clinical providers at selected facilities followed by a survey of all VHA medical centers. Aim 2: Gain an in-depth understanding of the Veteran home experience using video-reflexive ethnography and photo elicitation followed by a survey assessment of Veteran experiences with a broader sample of OPAT patients. Aim 3: Design interventions to enhance OPAT safety and delivery in collaboration with Veterans, their caregivers and clinical care providers. Methodology: This study uses qualitative and quantitative methods to understand how OPAT is delivered across VHA, how patients and caregivers experience at-home OPAT and a user-centered design approach to develop interventions to address OPAT-related challen...