This study uses geocoded address data and information about parents' economic behavior and children's development from four random-assignment welfare and anti-poverty experiments conducted during the 1990s. We find that the impacts of these welfare and anti-poverty programs on boys' and girls' developmental outcomes during the transition to early adolescence differ as a function of neighborhood poverty levels. The strongest positive impacts of these programs are among boys who lived in high-poverty neighborhoods at the time their parents enrolled in the studies, with smaller or nonstatistically significant effects for boys in lower-poverty neighborhoods and for girls across all neighborhoods. This research informs our understanding of how neighborhood context and child gender may interact with employment-based policies to affect children's well-being. (Contains 7 tables.)