There are few applied models for understanding large-scale spread and scale-up of evidence-based interventions. This project will create and test such a model in partnership with CTC’s ongoing activities to translate scientific findings into practical solutions for criminal legal populations. Forty-eight interviews will be conducted with a combination of JCOIN 1.0 researchers and other HEAL-funded researchers conducting criminal legal-related studies; individuals with criminal legal incarceration experience; research participants in JCOIN Hub studies; and implementation experts to understand what elements and processes should be included in a novel Implementation Translation Spread and Scale-Up (I-TranSS) Model. Interviews will consist of questions about how to best spread and scale up encouraging findings from recent clinical trials. Topics will include what types of messages to use, intended communication channels for decision-makers, anticipated barriers, implementation strategies, facilitators of implementation, and outcomes to assess. Collectively, these can inform better I-TranSS specification and application. Through formative work and iterative development over the course of JCOIN 2.0, this model will be designed to assist practitioners and researchers in the field with their spread and scale-up initiatives to increase the use of targeted EBIs dramatically.