ABSTRACTThis ethnographic cross‐case study examines five teachers' year‐long efforts to implement practice‐based physics instruction within the unique organizational context of a no‐excuses charter network. The teachers were attempting to adapt their didactic, rigid, and compliance‐based instructional approach to include more opportunities for students to figure out disciplinary concepts through evidence and consensus. To assist in these efforts, teachers partnered with a university‐based physics education program to redesign the network's coherent instructional infrastructure. The program provided curricular materials aligned with the Next Generation Science Standards, facilitated professional learning sessions, and assisted with instructional coaching before and during the 2018–2019 school year. Researchers collected ethnographic field notes and artifacts during professional learning sessions, partnership meetings, and bi‐weekly lesson observations of case teachers. They also conducted interviews with teachers and students. An organizational sensemaking lens was used to analyze data and informed the production of ethnographic case profiles, vignettes, and cross‐case comparisons. Findings included the constraints and affordances of a coherent instructional infrastructure for facilitating teacher sensemaking. Hybridized instructional practices also emerged across case teachers' classrooms as products of facilitated sensemaking. Implications for supporting teachers in fitting novel instructional approaches to their organizational contexts are discussed. This paper is part of the special issue on Teacher Learning and Organizational Contexts.