Antecedents of enrollment in social health insurance among small and medium-sized enterprises (SMEs)

Despite the potential of social health insurance to protect against catastrophic health expenditures, enrollment among small and medium-sized enterprises (SMEs) in Tanzania remains low. This study examines how SMEs’ capability and opportunity influence enrollment behavior directly and via motivation and how institutional trust shapes and moderates these relationships. Data were collected from 269 SME owners and managers in Dar es Salaam. Partial least squares structural equation modeling was employed to test the proposed model. Findings reveal that institutional trust is the strongest determinant of enrollment, while motivation mediates the effect of capability and opportunity. Specifically, capability drives enrollment indirectly through motivation, whereas opportunity exerts both direct and indirect effects. Trust further amplifies the motivational pathway, demonstrating the conditional role of institutional trust. This study advances the capability–opportunity–motivation–behavior theory by incorporating institutional trust and offers actionable guidance for policy makers and practitioners, to enhance SME enrollment through trust-building and access-oriented strategies.