Purpose: This article presents findings from a study of six schools in the Together Initiative (TI), which facilitates increased school autonomy from districts and expands teacher decision-making authority. This study aims to understand how TI's theory of action changed structures, cultures, and agency as the concepts of "site-based management" and "expanded teacher decision making" were interpreted and implemented by district and school leaders and teachers. Research Design: Data were collected over the first 2 years of the initiative using a concurrent mixed-methods design. Field notes from more than 200 hours of observations and transcripts of 231 semistructured interviews with stakeholders were coded using the constant-comparative method. Findings from qualitative data were triangulated with annual teacher survey findings. Findings: Implementation of TI varied across the six schools and depended greatly on school staffs' existing relationships the district, principal support for decision-making structures, and the extent to which school cultures reflected trust and teachers were able to enact greater agency. Only two schools experienced moderate increases in site-based management and expanded teacher decision making; those that did not were missing at least one of these structural or cultural supports. Conclusions: At a time when charter schools are touted as an effective reform model, this article informs policy and practice on the original charter concept--autonomous, innovative district schools. Our findings suggest that creating contexts where site-based management can flourish is far more complicated than changing structures or establishing supportive school cultures.