Mounting evidence of the effectiveness of active learning strategies has prompted many mathematics departments to start engaging in transformational change efforts. Change, however, especially change in instructional practice, is a challenging endeavor. Some departments are using coordination of multi-section courses as a vehicle to enact changes and have designated or hired course coordinators to oversee efforts to transform instruction via active learning. This study explores the role of coordinators as instructional change agents for active learning using data collected from five university mathematics departments, all of which are successfully sustaining such efforts. We use Shadle et al.'s drivers for change as a framework for examining data from five retrospective case studies of change. Specifically, we investigate how these speculative drivers connect to coordinators' roles as change agents in each story. We argue that coordinators are positioned to leverage three key drivers for change: providing materials and tools, encouraging collaboration and communication, and encouraging (and providing) professional development. Coordinators must also understand the local contexts and culture in order to engage in effective processes for supporting departmental change. To conclude, we discuss implications of this research for departments seeking to transform instruction.