We develop a conceptual governance framework to guide the creation and management of a modular network to address complex social problems. Drawing on theoretical foundations in modularity and inter-organizational networks, we propose that modularization of complex social problems is a dialectic, emergent process that blends a convener-led network formation with consultative problem definition and solution design. We also posit that social systems are imperfectly modular and need purposefully designed interface governance to integrate the modules. Finally, we advance how modularity may be leveraged to simultaneously advance the interests of participating actors and deliver societal value. The propositions together advance a governance framework for a modular, multi- actor adaptive system suited to tackle the scale, diversity and dynamics of complex social problems.