Studies across the STEM disciplines have shown that active learning improves student engagement, retention, and understanding, with the largest impact on women and previously low-achieving students. Embedding active learning into large enrollment gateway has the potential to improve outcomes for thousands of students every year, but effecting large-scale change across multiple instructors, sections, and courses is challenging. We are building and supporting multi-generational teams of faculty, graduate teaching assistants, and undergraduate learning assistants to help make active learning a more integral part of the classroom experience in gateway courses in several STEM disciplines. We are using a Communities of Practice (CoPs) framework to bring together and support these teams as they seek to make change. CoPs centered around teaching provide opportunities for instructors to share teaching knowledge and experience, as well as to build community and ongoing conversation among colleagues with similar interests or concerns. Our effort has taken a layered approach to CoPs to both support the multigenerational teams and to help spread the effort beyond these teams. We have built and interwoven course-based communities, GTA communities, departmental communities, and cross-departmental communities. This session will introduce our efforts to build CoPs and some of the differences in structure for the different communities. We will ask the audience to consider what CoPs might help support their change effort and what characteristics will be important for each one. We will debrief on how one might build these communities and weave them together into an effective effort for change.