BackgroundMany low-and middle-income countries have adopted social health insurance schemes. However, the collection of contributions from the large informal sector of these economies poses a significant challenge. Employing an integrated system of contribution collection from all relevant institutions may be cost-effective. We used the integrative framework for collaborative governance, to explore and explain factors that may shape the governance of an integrated system for collecting contributions for social health insurance, pension, and taxes from the informal sector in Zambia.MethodsWe undertook a qualitative case study involving 25 key informants drawn from government ministries and institutions, cooperating partners, non-governmental organizations, and association representatives in the informal sector. Data were analyzed thematically using Emerson’s integrative framework for collaborative governance.ResultsThe main drivers of collaboration included a need for comprehensive policies and legislation to oversee the integrated system for contribution collection, prevent redundancy, reduce costs, and enhance organizational effectiveness. However, challenges such as leadership issues and coordination complexities were noted. Factors affecting principled engagement within the collaborative regime consisted of communication gaps, organizational structure disparities, and the adoption of appropriate strategies to engage the informal sector. Additionally, factors influencing shared motivation involved concerns about power dynamics, self-interests, trust issues, corruption, and a lack of common understanding of the informal sector.ConclusionThis study sheds light on a multitude of factors that may shape collaborative governance of an integrated system for contribution collection for social health insurance, pension, and taxes from the informal sector, providing valuable insights for policymakers and implementers alike. Expanding social health insurance coverage to the large but often excluded informal sector will require leveraging factors identified in this study to enhance collaboration with pension and tax subsystems.