In this article, we present findings from our first iterative design study for Project ENHANCE to share our findings as well as provide an exemplar for others engaged in design inquiry. In particular, we explain how we used a data-informed design process with district partners to determine content and features of three foundational professional learning modules to support implementation of integrated tiered systems of support. We report findings from three groups of individuals: advisory board and expert panel members (Phase 0), Ci3T Leadership Team members (Phase 1), and role-specific user groups from school faculty and staff (Phase 2). Results indicated acceptability and overall usability of content from multiple perspectives, with priority placed on smaller units of professional learning and flexible resources (e.g., videos infographics). Results also raised questions about how to use resources without overwhelming teachers as they manage multiple responsibilities within a finite amount of time. We discuss limitations and future directions.