["The International Journal of Health Planning and Management, EarlyView. ", "\nABSTRACT\n\nBackground\nImproving health system performance in decentralised settings requires coordinated governance structures, sustainable financing mechanisms, and targeted equity policies. However, empirical evidence on how these institutional mechanisms interact to influence service delivery, financial protection, and equitable access remains limited in many low‐ and middle‐income countries.\n\n\nMethods\nThis study examined the determinants of health system performance in Southwest Nigeria using cross‐sectional survey data collected from health sector stakeholders. Robust ordinary least squares regression models with heteroskedasticity‐consistent standard errors were estimated to assess the relationships between governance coordination, financing reform implementation, equity‐targeted interventions, and three performance outcomes: service delivery effectiveness, financial access protection, and equitable access to care. State fixed effects and stakeholder and organizational controls were included in all models.\n\n\nResults\nGovernance coordination demonstrated a significant positive association with service delivery effectiveness in the baseline model (β = 0.295, p < 0.01). Financing reform implementation was strongly associated with improved financial access protection (β = 0.311, p < 0.01), while equity‐targeted interventions exhibited the strongest and most consistent relationship with equitable access outcomes (β = 0.335, p < 0.01). Expanded institutional models revealed that public trust was positively associated with multiple performance indicators, whereas corruption displayed a negative relationship with financial protection and service delivery outcomes.\n\n\nConclusion\nThe findings suggest that health system performance improvements are driven by the combined effects of governance coordination, pooled financing mechanisms, and equity‐focused policy interventions operating within supportive institutional environments. Strengthening intergovernmental coordination, expanding financial risk‐pooling arrangements, and prioritising targeted equity policies may substantially enhance progress towards universal health coverage in decentralised health systems.\n\n"]