This study examines the impact of organizational purposes and values on reforming physics instruction to align with a practice-based instructional approach, in a case of engaging in infrastructuring with a no-excuses charter network. The network's instruction was guided by organizational purposes of ensuring predictable academic success and collegiate access for all students and was supported by a robust system of instructional infrastructures that were initially incoherent with a practice-based approach to science education. To manage this incoherence, the network engaged in infrastructuring with a university-based team of physics education researchers and curriculum developers. Infrastructuring included the redesign of network standards, curricular materials, assessments, instructional coaching routines, and professional development workshops during a 33-month partnership. Extensive ethnographic data were collected during this process and analyzed using a mixture of inductive and deductive coding that facilitated the production of analytical memos, interpretive vignettes, and cross-case comparisons. Analysis revealed reform motivations unique to the no-excuses context and elements of instructional infrastructures that were mutable and immutable to change. During implementation, some redesigned infrastructure elements supported a practice-based approach to physics instruction, including adaptations to daily instructional materials and valued student learning outcomes. Other infrastructure elements constrained reform efforts, including expectations of standards coverage. Implications for instructional reform programs and working with no-excuses networks are discussed.