Home healthcare (HHC) is the fastest growing healthcare sector and an important source of care for older Americans, including populations that historically have been vulnerable to health disparities. HHC patients are at high risk for infections. The COVID-19 pandemic has put a spotlight on infection prevention and control (IPC). However, our prior work indicates that HHC IPC capacity (i.e., IPC staffing, general IPC procedures, infection specific policies and employee IPC training policies) was sub-optimal and IPC preparedness (i.e., planning for and responding to an infectious disease crisis) was insufficient before the pandemic. Informed by our work in the parent grant “Infection Prevention in Home Health Care (InHOME, R01 NR016865)” and guided by Donabedian’s Quality Model and the Minority Health and Health Disparities Framework, in this competitive renewal we propose a 5-year, mixed methods study with 4 aims: 1) To describe changes in HHC IPC capacity and preparedness over time and its association with vulnerable populations; 2) To examine associations between HHC IPC capacity and HHC patient outcomes, overall and in vulnerable populations; 3) To examine the feasibility and potential barriers to implementing best practices in IPC capacity and preparedness through qualitative interviews with HHC personnel; and, 4) To develop evidence-based recommendations for improving HHC IPC capacity and preparedness to reduce the burden of COVID-19 and non-COVID-19 infections in HHC. In Aim 1, we will conduct two national surveys of HHC agencies (n = 600 per survey) in 2022 and 2024 and link them with our 2019 survey. We will assess the evolution of HHC IPC capacity and preparedness across the nation. In Aim 2, we will estimate the associations between HHC IPC capacity and HHC patient outcomes (infections, mortality) by linking our surveys with longitudinal HHC assessments (i.e., the Outcome and Assessment Information Set), Medicare claims and encounters data, and COVID-19 environment data. In Aim 3, we will conduct qualitative interviews with 60 purposively selected HHC personnel (i.e., 20 HHC agencies, 3 participants per agency) to discuss our findings, gather insights, and gain perspectives from those with firsthand experience implementing IPC policies and caring for patients. In Aim 4, we will conduct systematic literature review and synthesize our findings to inform a Delphi panel made up of key stakeholders (i.e., experts, leaders, advocates, patients and caregivers). We will develop clinical and policy recommendations refined and endorsed by our Delphi panel. This will result in data-driven, evidence-based recommendations that we will widely disseminate. Our multidisciplinary team is uniquely qualified to conduct this study. Leveraging our unique baseline data, our study will be the first comprehensive examination of IPC changes in HHC through the pandemic and its impact on patient outcomes. The results will provide recommendations to strengthen HHC ...