Purpose: This research note presents a secondary data analysis of language impairment (LI) prevalence rates of children in public schools before and after a statewide mandate for response-to-intervention (RTI) implementation. Method: Statewide and district-level LI prevalence rates were compared across 10 school years. Prevalence data from 67 school districts located in 1 state in the United States are reported as the proportion of the general student population (students ages 3-21 years) who were identified with a primary disability of LI. Results: The mandated implementation of RTI within special education prereferral, evaluation, and eligibility processes coincided with significant changes in LI prevalence as a primary disability for most of the school districts. The majority of school districts experienced an increase in LI prevalence within 1 school year following RTI implementation. However, the degree and direction of change in prevalence rates varied across some of the school districts. Similar degrees of change were not evident across the other years of prevalence data review, suggesting the systemic change that occurred via RTI requirements coincided with fluctuations in the LI prevalence rates for the majority of school districts in the state. Conclusion: A causal relation between RTI and LI prevalence cannot be established with the current data; however, this study establishes a temporal connection between the timing of RTI implementation and changes in LI prevalence in public schools of 1 very large state. Implications are presented for further research investigating the potential impact of systemic mandates on the identification of school-age children with LI.