PROJECT SUMMARY ABSTRACT The NIH has called for testing promising implementation strategies (PAR-19-274) and there is a critical need for implementation and sustainment of effective and evidence-based practices (EBPs) to address health conditions including substance use disorders (SUDs). This proposed project is consistent with NIDA’s Priority Focus Area “Strategies to improve the effective and sustainable implementation of evidence-based prevention and treatment interventions (implementation science).” Most implementation strategies do not address the complex multilevel context for implementation in public service sectors. This proposed project will expand the Leadership and Organizational Change for Implementation (LOCI) intervention, an innovative organizational change strategy for EBP implementation and sustainment, to include partnership with a statewide Department of Mental Health and Addiction (DMHA) and Community Mental Health Centers (CMHCs) in order to align state-level leadership policies and directives with organizational implementation improvement strategies. SUDs are among the most complex of public health issues and Indiana ranks as the fourth worst state in providing SUD services with about 8.5% of the population meeting criteria for a SUD, of whom only 13.6% seek treatment. Indiana DMHA approached the UCSD LOCI team to aid in the implementation of combined Motivational Enhancement Therapy/Cognitive Behavioral Therapy (MET/CBT) The main innovation in this project is that, consistent with the Exploration, Preparation, Implementation, Sustainment (EPIS) framework and system and organizational theory, we will add a system level component to LOCI with the goal of bridging outer and inner context and developing and aligning a positive implementation climate to support implementation and sustainment of MET/CBT for SUDs. This project will test an implementation strategy that seeks to align, system, organization, and clinic leadership and strategies to implement and sustain an EBP for substance use disorders. The Leadership and Organizational Change for Implementation - System Level (LOCI-SL) seeks to improve implementation leadership, climate, provider attitudes and behaviors, and EBP fidelity and client engagement in services. LOCI- SL will be tested in a statewide mental health and addiction service system and its community mental health centers.