Background: Building Circles of Support is an innovative strategy for developing natural support networks. This study explored some of the ambiguity in the conceptualisations, operational elements, and perceived outcomes of Circles of Support programs. Method: A comparative case study of three Australian Circles of Support programs was conducted. Data included document review and qualitative interviews with 27 key stakeholders. Qualitative analysis of the data from each program was analysed using categories of the program logic as a conceptual framework, followed by cross-case analysis to identify commonalities and differences. Results: Findings show conceptual variability between programs, which shared similar overarching intents but differed in program, strategies, target population and outcomes, which were shaped by the missions of the organisation of which they were part. Conclusion: Findings can inform the future design and evaluation of programs to support the development of informal support network for people with intellectual disabilities.