Prior research has found that public investments in North Carolina's pre-kindergarten program--NC Pre-K--generated positive effects on student reading and math achievement through eighth grade (Bai et al., 2020). This study examined whether the effect of NC Pre-K funding exposure is moderated by the educational environments children subsequently experience during elementary and middle school. The NC Pre-K effect on student reading and math achievement in eighth grade was found to be larger in school districts with lower rates of growth in academic achievement. These findings suggest that public investments in early childhood education may be particularly beneficial in the long term for children who subsequently experience low-growth school environments--consistent with a dynamic substitutability hypothesis of combined effects.