Prior research has found that financial investments in North Carolina’s early childhood education programs—Smart Start and NC Pre-K—generated positive effects on student achievement in reading and mathematics through eighth grade (Bai et al., 2020). The current study examined if these effects were moderated by two dimensions of educational opportunity in NC public school districts, as measured by (1) the average level of academic achievement among third-grade students in the school district and (2) the rate of growth in academic achievement among students in the school district as they progressed from third to eighth grade. The Smart Start effect on eighth grade reading achievement was larger in school districts with higher levels of average achievement. Also, the NC Pre-K effect on eighth grade reading achievement was smaller in school districts with higher rates of achievement growth. (author abstract)