OBJECTIVE: The goal was to estimate the number of children and adolescents, 0 to 19 years of age, living with spina bifida (SB) in the United States. METHODS: A retrospective study was conducted by using population-based, birth defect surveillance data from 10 US regions, with vital status ascertainment. Birth defect surveillance data were obtained from Arkansas, Georgia (5 central counties of metropolitan Atlanta), California (11 counties), Colorado, Iowa, New York (New York City excluded), North Carolina, Oklahoma, Texas, and Utah. We estimated the numbers of children 0 to 19 years of age who were living with SB in the 10 US regions in 2002, according to age group, race/ethnicity, and gender, and examined a long-term trend in the prevalence of SB among children 0 to 11 years of age in 1991-2002. RESULTS: The overall prevalence of SB among children and adolescents 0 to 19 years of age in the study regions was 3.1 cases per 10 000 in 2002. The prevalence of SB among children was lower among male and non-Hispanic black children. CONCLUSIONS: The prevalence estimates of SB among children and adolescents varied according to region, race/ethnicity, and gender, which suggests possible variations in prevalence at birth and/or inequities in survival rates. Additional studies are warranted to elucidate the reasons for these variations and to derive prevalence estimates of SB among adults. Copyright © 2010 by the American Academy of Pediatrics.