Although most states have implemented a QRIS, rigorous causal research to estimate the impact of such investments is limited. QRIS research has focused primarily on implementation and validation of quality rating indicators. Using the variation in the timing of QRIS implementation across the first 25 states that implemented a system, the proposed study will use a comparative interrupted time series (CITS) approach to estimate the impacts of QRISs on children’s later academic outcomes in reading and mathematics measured by the National Assessment of Educational Progress (NAEP). The sample will focus on children who are from lower-income households (based on their eligibility for free/reduced lunch). The study will also examine how the effects of QRISs on children’s later academic outcomes (in Grade 4) vary based on how the QRIS is implemented. Specifically, the study will investigate whether differential effects exist across QRISs by how they set up their rating structure and by whether the QRIS offers financial incentives or technical assistance. (author abstract)