This study examines associations between enrollment in high-quality PreK and growth in children's (N = 422; M[subscript age] = 5.63 years; 47% female; 15% Asian, 19% Black, 30% White, 31% Hispanic; 5% other or mixed race) academic, executive functioning, and social-emotional skills across kindergarten (2017-2018) and first grade (2018-2019). Associations between PreK enrollment and language and math skills were sustained through first grade. More convergence between PreK enrollees and non-enrollees in language skills occurred during first grade than kindergarten. Convergence patterns were stronger in math during kindergarten than in first grade. There were no associations between PreK enrollment and executive functioning by spring of first grade; most convergence occurred in first grade. All other associations were null by first grade.