BACKGROUND:
Community Health Workers (CHWs) are central to South Africa’s primary health care (PHC) reforms but remain under-recognised as actors who can coordinate care across sectors. While policy promotes integrated, people-centred care, fragmented governance and siloed services often limit its implementation. This paper reconceptualises CHWs as boundary spanners (actors who connect communities, services, and decision-making spaces) and introduces a realist-informed Theory of Change (RiToC) to support this shift.

METHODS:
We conducted a qualitative realist-informed conceptual synthesis drawing on four linked data sources: a realist synthesis of CHW studies from sub-Saharan Africa; a realist evaluation of CHW–household interactions; a realist evaluation of a collaborative governance platform; and a systems-level reframing of the WHO Integrated People-Centred Health Services framework. Insights were integrated into a RiToC to explain how CHWs can be supported to perform integrative roles across health, social, and governance systems.

RESULTS:
CHWs already connect households with clinics, social services, and local governance structures, but these roles are often informal and poorly supported. We identified seven strategic levers to strengthen CHWs’ capacity as boundary spanners: layered accountability, shared ownership across sectors, equitable resourcing, intersectoral training, professional recognition, adaptive implementation models, and multisectoral integrated tools. These levers operate through mechanisms of trust, motivation, and professional legitimacy, which together enable CHWs to coordinate care across sectors.

CONCLUSIONS:
CHWs function as de facto boundary spanners within South Africa’s PHC system. To unlock their full potential, health systems must redesign governance and support structures. Key actions include formalising CHWs’ roles in intersectoral platforms, strengthening accountability and referral feedback loops, investing in cross-sectoral training and professional recognition, and introducing integrated tools that support coordination. Methodologically, this study advances the use of a realist-informed Theory of Change as a practical and transferable approach for designing people-centred health system reforms in complex, resource-constrained settings.