Communities nationwide have formed cross-sector partnerships to face the needs of an aging population, particularly for the purpose of improving long-term supportive service systems. Research is limited on how evaluation strategies are incorporated into partnership work, especially in the field of aging. This retrospective qualitative study reviewed administrative and key informant interview data to examine how 15 community partnerships (CPs) within the Community Partnerships for Older Adults (CPFOA) national program incorporated evaluation into their work. The four overarching lessons drawn from our inquiry suggest that effective CPs: (a) incorporate both formative and summative methods into evaluation, (b) use and develop the knowledge and skills of its members, (c) support flexible and creative evaluation methods and strategies, and (d) use internal and external resources to support evaluation efforts, particularly with nontraditional partners. There is a need for continued research to capture the methodological complexity of partnership evaluation.