PROJECT SUMMARY Approximately 3 million known persons living with dementia (PLWD) visit the emergency department (ED) annually. This is likely an underestimated value as most cases of dementia go unrecognized in the ED. Most PLWD are treated and released, implying that they do not need medical oversight and are on the road to recovery. Yet, for PLWD, the ED-to-home transition is associated with increased risk of ED revisits, adverse events, and mortality. The critical need for effective care transition interventions for PLWD has been identified by the NIA-funded Geriatric Emergency Care Applied Research 2.0 Network – Advancing Dementia Care. Our adaptation of the Coleman’s Care Transitions Intervention, delivered by community paramedics for community- dwelling older adults transitioning from ED-to-home, reduced the odds of ED revisits within 30 days by 75% among patients with cognitive impairment. These results lay the foundation for testing the Community Paramedic-Led Transitions Intervention (CPTI) in a large-scale embedded pragmatic clinical trial to rigorously evaluate its effectiveness in improving the ED-to-home transitions for PLWD. In this study, we will test our hypothesis that the CPTI will improve the ED-to-home transition and utilization outcomes for PLWD, both alone and when combined with other interventions. We will leverage community paramedicine, an innovative and new health care model where paramedics function outside their traditional roles to deliver community health interventions. We will optimize the CPTI across two sites in coordination with the Nurse-led Telephonic Care and ED Care Redesign for PLWD, assessing intervention acceptability and engagement. We will test the CPTI’s effectiveness alone and in combination with the other interventions in an 80-center, cluster- randomized, multifactorial embedded pragmatic clinical trial for community-dwelling PLWD and their care partners experiencing an ED visit by analyzing ED revisit rates, hospitalizations, and total days at home following an index ED visit. We will also determine site, provider, and patient-level characteristics that are associated with CPTI outcome variations using the RE-AIM framework, such that future implementation can adequately address these care gaps. Upon its completion, this study will address the important gap of overlooked ED-to-home transitions for PLWD receiving ED care. By rigorously investigating the CPTI, we will provide critical evidence on ways to improve PLWD health outcomes and enable underutilized healthcare resources for this vulnerable population.