Objective To examine whether delays in seeking care are associated with worse health outcomes or increased treatment costs,in children, and then assess whether insurance coverage reduces these delays. Study design We use data on 4070 children younger than 5 years from the Quality Improvement Demonstration Study, a randomized controlled experiment assessing the effects of increasing insurance coverage. We examined whether delay in care, defined as greater than 2 days between the onset of symptoms and admission to the study district hospitals, is associated with wasting or having positive C-reactive protein levels on discharge, and with total charge for hospital admission; we also evaluated whether increased benefit coverage and enrollment reduced the likelihood of delay. Results Delay is associated with 4.2% and 11.2% percentage point increases in the likelihood of wasting (P = .08) and having positive C-reactive protein levels (P = .03), respectively, at discharge. On average, hospitalization costs were 1.9% higher with delay (P = .04). Insurance intervention results in 5 additional children in 100 not delaying going to the hospital (P = .02). Conclusions In this population, delayed care is associated with worse health outcomes and higher costs. Access to insurance reduced delays; thus insurance interventions may have positive effects on health outcomes. (J Pediatr 2009,155:281-5).