This qualitative study examined the actions of district and school leaders in changing from a traditional age-based grade-level structure to a standards-based student grouping model in a Western school district. Based on interview, observation, and artifact data collected over 5 years, the findings identify specific leadership actions that advanced fundamental cultural, structural, and procedural changes in schools and classrooms across the district regarding student achievement of the state's learning standards, as well as the challenges encountered in the change process. Because of the variance in size, diversity, and socioeconomic status of the three communities that comprised the school district, the findings address community and district contextual factors that promoted or impeded the change process. (Contains 2 notes, 1 table, and 1 figure.)