This paper presents the protocol for a non-randomized trial of a multi-level stigma intervention called Combatting Stigma to Aid Reentry and Recovery (CSTARR) that involves two interventions: (1) training for criminal legal staff to address public stigma and (2) group-based acceptance and commitment therapy to address self-stigma among legally-involved adults enrolled in substance use treatment. Staff and client participants are engaged with a program called the Tennessee Recovery Oriented Compliance Strategy in 6 East Tennessee counties. This study examines the feasibility, acceptability, and preliminary effectiveness of CSTARR using a type 1 hybrid implementation/effectiveness trial with pre to post follow-up.