Since the early 2000s, a global age-friendly communities (AFC) movement has called for improving the built, social, and service environments of localities for aging. Yet research on the outcomes of AFC initiatives, as programmatic efforts toward AFC progress, remains in its nascence. Drawing on "The Water of Systems Change" framework, our study aimed to address this gap by exploring the extent to which accomplishments of AFC initiatives are indicative of altering six conditions for systems change: policies, organizational practices, resource allocations, power dynamics, relationships, and mental models. We analyzed qualitative data from 26 key informant interviews across eight mature AFC initiatives in the northeastern United States. We engaged in iterative phases of thematic analysis to explore how the initiatives' accomplishments, as described by the participants, align with each of six focal conditions for systems change. We found especially robust and consistent evidence for outcomes in terms of enhanced organizational practices on aging; resource flows; connections within and across communities; and mental models about older adults. Evidence for outcomes concerning changes in power dynamics and policy was more limited. Conceptualizing AFC initiatives as systems-change interventions can bolster research, evaluation, and program development as the movement proliferates and diversifies into the 21st century. Insights can help to advance praxis that empowers AFC leaders as changemakers for "successful aging" at the level of society.