Booster seat laws are premised on the need to improve seat belt fit for young children to reduce their injury risk. This paper provides the first extensive examination of national crash data for children in seat belts. Using regression and other models, we found no evidence that crash-involved children ages 4-7 in lap-shoulder belts fare worse on average than similarly restrained children ages 8-13 or, in sensitivity analysis, than similarly restrained adults ages 18-34. If anything, they may fare better.