In 2020, 359 campuses, representing a wide range of institutional diversity in American higher education, have achieved the elective community engagement classification from the Carnegie Foundation. To receive the classification, campuses must provide extensive documentation (through an application) indicating a commitment to institutionalizing community engagement. When they do so, the Carnegie Foundation recognizes community engagement as part of the institutional identity of the campus. Unlike the basic Carnegie classification, which all campuses receive, the community engagement classification was designed to augment the basic classification in a way that encouraged campus innovation and change. What the authors offer, based on the experience of reviewing hundreds of applications for the classification, is that the Carnegie Foundation was not only encouraging campus change, but that the design of the classification suggests a theory of how institutionalization of community engagement happens. The authors have found that when working with campuses that are preparing applications, understanding the theory of change implied by the classification has been helpful in focusing attention on the importance of community engagement being located in the core academic cultures, policies, structures and practices of the campus.