 This study aims to explore the underlying causal mechanisms by which primary healthcare, PHC, leavers can contribute to universal health coverage, UHC. It will use a realist evaluation approach to identify and analyze the programmatic theories behind PHC and its impact on UHC. The study will also conduct a comprehensive literature of you to identify relevant evidence and synthesize it into a coherent narrative. The results of this study will provide insights into how PHC leavers can be used to improve health systems and achieve UHC. This article was authored by Ubelta Lasefa, Daniel Urqu, Akliluyn Dalamo, and others.