PROJECT SUMMARY In response to PAR-21-235, we propose to systematically and iteratively redesign an autism implementation toolkit, entitled Autism Community Toolkit: Systems to Measure and Adopt Research-Based Treatments (ACT SMART), for middle and high schools to meet the community-identified need for tools enabling the appropriate identification and selection of autism evidence-based practices (EBPs). Unmet service needs and care disparities are common for autistic adolescents, contributing to poor outcomes and deleterious public health effects. Public schools are the most frequently accessed service system for autistic youth and schools are mandated to provide research-supported practices for autistic students. Yet, routine use of EBPs is limited and the quality of school programming is low. Educators receive limited support in identifying and selecting autism EBPs, likely contributing to poor implementation and sustainment, with downstream effects on adolescent outcomes. To date, most school implementation efforts have focused on the later implementation phases (active implementation) versus the earlier phases (adoption-decision) critical to implementation success. There is a critical need for systematic supports targeting autism EBP selection and decision making in public schools. This proposal addresses these gaps through iteratively redesigning an autism implementation toolkit targeting EBP decision-making. Funded by NIMH (K01MH093477), the ACT SMART implementation toolkit was developed and shown effective in targeting autism EBP adoption and decision-making in community settings. ACT SMART has immense potential to improve autism EBP decision-making, adoption, and implementation in schools; however, systematic and iterative redesign is necessary to optimize its fit to the unique context of public schools. The Exploration, Preparation, Implementation and Sustainment (EPIS) and Discover, Design, Build, and Test Framework (DDBT) frameworks will be applied to redesign ACT SMART. EPIS was selected given its specific development for public child service settings and application to the original development of ACT SMART, while DDBT provides the necessary guidance regarding implementation strategy development to enhance the usability and contextual fit. The proposed study is highly responsive to NIMH (e.g., Strategy 4.2C developing decision-support tools that increase intervention effectiveness in public service settings) and the IACC (e.g., the need to expand research with autistic adolescents and the translation of efficacious interventions to the community) research priorities. The specific aims are: Aim 1. Engage stakeholders to identify targets for ACT SMART redesign to optimize its fit for middle and high school providers that work with autistic adolescents. Aim 2. Conduct prototyping and usability field testing of the refined ACT SMART and iteratively refine to ensure usability, feasibility, acceptability, and appropriateness for use in scho...