This study explores children's early academic and self-regulatory skills as potential pathways through which a preschool enrichment program -- the Chicago School Readiness Project (CSRP) -- may contribute to low-income children's long-term outcomes (N = 466; M age at baseline = 4.10 years). We find that CSRP's impact on high school grades may be partially explained by early gains in vocabulary and math skills. Although impacts on high school executive function (EF) were more equivocal, our results suggest that early improvements in math skills attributable to the intervention may, in turn, predict long-term gains in EF skills. These results complement the existing literature on preschool fade-out, while also shedding light on the cross-domain relations between academic and self-regulatory skills. [The paper was published in "Child Development" Sep-Oct 2019 (EJ1228756).]