The effectiveness of school-based programs and projects in decentralized education systems increasingly hinges on schools’ capacity to mobilize community stakeholders and sustain collaboration with external institutions, yet empirical evidence at the elementary level remains limited, particularly in geographically isolated contexts such as Catanduanes, Philippines. Anchored in the School-Based Management (SBM) framework, this study examined the levels of community engagement and institutional collaboration and analyzed their individual and combined influence on the effectiveness of school-based program implementation in public elementary schools in Zone 2 of the Division of Catanduanes using a quantitative descriptive– correlational design with a predictive component. Data were gathered from 215 randomly selected elementary school teachers through a validated researcher-developed questionnaire, with weighted means to determine variable levels and Pearson’s correlation and multiple regression analyses to test relationships and predictive effects. Results showed that both community engagement and institutional collaboration were rated at high levels, with participation in decision-making and joint planning emerging as the strongest dimensions, while program implementation was likewise perceived as highly effective, particularly in planning and monitoring processes. Statistical analyses revealed strong and significant associations between community engagement and program effectiveness (r = 0.724) and between institutional collaboration and effectiveness (r = 0.704), while regression findings confirmed that both variables significantly predict program effectiveness, with community engagement emerging as the stronger predictor. Overall, the findings highlight the critical role of participatory governance and coordinated institutional support in strengthening school-based programs and provide empirical grounding for a targeted action plan to enhance stakeholder participation, cross-agency collaboration, and governance practices, thereby contributing to the advancement of Sustainable Development Goal 4 on inclusive and quality education

Keywords: participatory governance; stakeholder partnerships; decentralized education; program implementation effectiveness; basic education management; school leadership support; SDG-4