This study estimated the prevalence of specific language impairment (SLI) in monolingual English-speaking kindergarten children. A stratified cluster sample of 7,218 children from rural, urban, and suburban areas in the upper Midwest was screened. The language screening failure rate was 26.2%, and a diagnostic battery was administered to 2,084 children, including those who failed the screening and a similar number of controls. The estimated overall prevalence of SLI was 7.4%, with 8% among boys and 6% among girls. Prevalence varied among children of different racial/cultural backgrounds, but these factors were correlated with parental education, which was also associated with SLI. Parents of 29% of the children identified as SLI reported they had previously been informed that their child had a speech or language problem. The prevalence estimates fell within recent estimates for SLI, but demonstrated that this condition is more prevalent among females than previously reported. The clinical identification of these children remains low among kindergarteners. SLI is a developmental language disorder characterized by unexpected difficulties in acquiring spoken language. Children with SLI are at risk for social and behavioral problems and educational difficulties. The prevalence of SLI is important for understanding its impact on society and is used for public policy and planning. Variations in prevalence can help identify risk factors for the condition. The study used a stratified cluster sample of kindergarten children who were monolingual English speakers. The sample was stratified by residential setting and cluster sampled according to school building. The study was conducted in three regions of Iowa and Illinois. The sample was drawn from three regions of the states of Iowa and Illinois. The study used a cross-sectional design with a two-stage identification procedure. All children were screened with a brief language screening test, and those who failed the screening and a sample of those who passed were administered a diagnostic battery for SLI. The study found that the prevalence of SLI was 7.4%, with 8% among boys and 6% among girls. The prevalence varied among children of different racial/cultural backgrounds, but these factors were correlated with parental education, which was also associated with SLI. The study also found that the prevalence of SLI was higher among males than females. The study also found that the prevalence of SLI was higher among Native American and African American children than among White children. The study also found that the prevalence of SLI was higher among children who had a second language at home than among those who did not. The study also found that the prevalence of SLI was higher among children who had a speech or language problem reported by their parents. The study also found that the prevalence of SLI was higher among children who had a more severe language impairment. The study also found that the prevalence of SLI was higher among children who had a more severe language impairment. The study also found that the prevalence of SLIThis study estimated the prevalence of specific language impairment (SLI) in monolingual English-speaking kindergarten children. A stratified cluster sample of 7,218 children from rural, urban, and suburban areas in the upper Midwest was screened. The language screening failure rate was 26.2%, and a diagnostic battery was administered to 2,084 children, including those who failed the screening and a similar number of controls. The estimated overall prevalence of SLI was 7.4%, with 8% among boys and 6% among girls. Prevalence varied among children of different racial/cultural backgrounds, but these factors were correlated with parental education, which was also associated with SLI. Parents of 29% of the children identified as SLI reported they had previously been informed that their child had a speech or language problem. The prevalence estimates fell within recent estimates for SLI, but demonstrated that this condition is more prevalent among females than previously reported. The clinical identification of these children remains low among kindergarteners. SLI is a developmental language disorder characterized by unexpected difficulties in acquiring spoken language. Children with SLI are at risk for social and behavioral problems and educational difficulties. The prevalence of SLI is important for understanding its impact on society and is used for public policy and planning. Variations in prevalence can help identify risk factors for the condition. The study used a stratified cluster sample of kindergarten children who were monolingual English speakers. The sample was stratified by residential setting and cluster sampled according to school building. The study was conducted in three regions of Iowa and Illinois. The sample was drawn from three regions of the states of Iowa and Illinois. The study used a cross-sectional design with a two-stage identification procedure. All children were screened with a brief language screening test, and those who failed the screening and a sample of those who passed were administered a diagnostic battery for SLI. The study found that the prevalence of SLI was 7.4%, with 8% among boys and 6% among girls. The prevalence varied among children of different racial/cultural backgrounds, but these factors were correlated with parental education, which was also associated with SLI. The study also found that the prevalence of SLI was higher among males than females. The study also found that the prevalence of SLI was higher among Native American and African American children than among White children. The study also found that the prevalence of SLI was higher among children who had a second language at home than among those who did not. The study also found that the prevalence of SLI was higher among children who had a speech or language problem reported by their parents. The study also found that the prevalence of SLI was higher among children who had a more severe language impairment. The study also found that the prevalence of SLI was higher among children who had a more severe language impairment. The study also found that the prevalence of SLI