Exclusionary discipline practices have a direct negative impact on individual students, schools, and society at large. To improve equity and cultural responsivity, active efforts to assess the contextual fit of effective strategies are necessary. The following study describes the Inclusive Skill-building Learning Approach (ISLA), an intervention designed to support school staff in carrying out preventative strategies and outlines instructional responses for educators and office staff. Additionally, an iterative approach to inform changes was used as part of the development process of ISLA. This paper aims to capture and incorporate the voices of students and staff using multiple methods to seek feedback for refining the quality, feasibility, and contextual fit of the ISLA intervention in middle schools. A total of 53 school staff provided feedback on the ISLA intervention. Further, Design Team members (n = 26) participated in semi-structured interview meetings to inform changes to ISLA. Last, student participants (n = 23) engaged in focus groups that were transcribed and coded via an independent co-coding strategy. The findings provide support for preventative school-based interventions that use alternatives to exclusionary discipline, as well as strategies for improving the ISLA intervention. [For the corresponding grantee submission, see ED618111.]