The Zero-Dose Learning Hub (ZDLH) conducted landscape assessments to provide a comprehensive overview of the immunization landscape within Bangladesh, Mali, Nigeria, and Uganda, with a specific focus on zero-dose (ZD) and under-immunized (UI) children. These landscapes synthesize findings from literature reviews and secondary data analyses to describe the current immunization context in each country, including coverage trends, equity, health systems, and existing programming, while also identifying important knowledge gaps. This presentation highlights the findings from the four country landscape scans and their implications for reaching ZD and UI children.