["Journal of Risk and Insurance, EarlyView. ", "\nAbstract\nAlthough many researchers have studied the introduction of social medical insurance schemes, few have examined their long‐term effects on children. This paper estimates the impact of China's Urban and Rural Resident Basic Medical Insurance (URRBMI) on children's health. The policy was rolled out gradually across Chinese provinces. Using recent econometric methods that avoid the issue of negative weights in staggered treatments, we show that URRBMI reduced sickness frequency. It also led to decreased hospital use and lower out‐of‐pocket costs. The policy also improved satisfaction, boosted insurance participation, and strengthened human capital indicators. We find stronger effects for boys and children living in urban areas. In contrast, the impact on rural children takes longer to appear. These results hold across different econometric methods and variable definitions.\n"]