Background: VA Community Living Center (CLC) staff struggle to address behavioral and neuropsychiatric symptoms of Veterans with dementia and serious mental illness (SMI) such as schizophrenia. These behaviors of distress (agitation, aggression, and mood disturbance) are not just associated with staff stress and burnout; they also hasten residents’ functional decline, decrease quality of life, and increase mortality. Staff training in non-pharmacological interventions can be effective. Yet systems barriers, task-based traditional biomedical care models, and time constraints often result in staff employing “quicker,” less effective strategies. Montessori Approaches to Person-Centered Care for VA (MAP-VA)— a staff training, intervention, and delivery toolkit— developed in collaboration with VA operational partners, Veterans, and frontline CLC staff is positioned to respond to this challenge. Our pilot data show probable impacts on CLC quality indicators at the individual and unit level (e.g., psychotropic medications, depressive symptoms, weight loss, falls, pain). Significance / Impact: Intense media scrutiny focused on care quality in VA CLCs has created an urgent problem for VA over the past year. To restore perceived trust, safety, and quality— as described in VHA’s Modernization Plan— frontline staff need to be empowered to lead quality improvement efforts like the ones taught through MAP-VA. Innovation: MAP-VA is distinct from existing interventions in its: 1) application to Veterans with a range of diagnoses and cognitive abilities; 2) emphasis on pairing practical skill-building for staff with overcoming system-level barriers that inhibit person-centered care; and 3) engagement of all staff rather than a reliance on provider-level champions. Yet, MAP-VA is a complex intervention that requires participation of multiple stakeholder groups, making implementation facilitation necessary. To date, no studies have evaluated MAP implementation success in operational settings (community or VA) and sustainability is rarely examined. Specific Aims: A hybrid (Type 3) implementation-effectiveness study is necessary to evaluate MAP-VA for Veterans and staff in CLCs. Study Aims include: 1) evaluate implementation facilitation and identify barriers to MAP-VA adoption and fidelity; 2) determine effectiveness of MAP-VA implementation on resident behavioral, emotional, and physical health outcomes; 3) determine effectiveness of MAP-VA implementation on person- centered care practices and organizational culture; and 4) examine the extent to which MAP-VA is sustained after external facilitation support has ended. Methodology: A stepped-wedge cluster randomized controlled trial will be used to evaluate within- and between-cluster implementation success and treatment effects over 18 months. Eight CLCs (24 CLC neighborhoods) will be randomized to a sequential crossover to the intervention with six months of facilitation. Analyses will account for time trends and c...