The COVID-19 pandemic has highlighted the persistent fragmentation of health systems and has amplified the necessity for integration. This issue is particularly pronounced in decentralise settings, where fragmentation is evident with poor coordination that impedes timely information sharing, efficient resource allocation and effective response to health threats. It is within this context that the Philippine Universal Health Care law introduced reforms focusing on equitable access and resilient health systems through intermunicipal cooperation, enhancing primary care networks and harnessing digital health technologies—efforts that underline the demand for a comprehensively integrated healthcare system. The WHO and the global community have long called for integration as a strategy to optimise healthcare delivery. The authors contend that at the core of health system integration lies the need to synchronise public health and primary care interventions to enhance individual and population health. Drawing lessons from the implementation of a pilot project in the Philippines which demonstrates an integrated approach to delivering COVID-19 vaccination, family planning and primary care services, this paper examines the crucial role of local health officers in the process, offering insights and practical lessons for engaging these key actors to advance health system integration. These lessons may hold relevance for other low-income and middle-income economies pursuing similar reforms, providing a path forward towards achieving universal health coverage.