Districts are relying on school autonomy to help schools differentiate educational programming for students and improve low-performing schools, yet we know little about how schools use autonomy in practice. Drawing on school case study and principal survey data from the Los Angeles Unified School District, we find variation in perceived school leader autonomy stemming from each school model's governance design, district-provided capacity building, and other organizational conditions. Principal perceptions of autonomy are positively associated with perceived implementation ease of school plans which, in turn, is positively related to reports of teacher collegiality and responsive school practices.