Theory and limited research indicate that race and socioeconomic status (SES) interact dynamically to shape children's developmental contexts and academic achievement, but little scholarship examines how race and SES intersect to shape Black-White achievement gaps across development. We used data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 (N [approximately equal to] 9,100)--which tracks a nationally representative cohort of children in the United States--to investigate how race and family SES (i.e., parental education and household income) intersect to shape trajectories of academic skills development from kindergarten entry through the spring of eighth grade. Results reveal that household income and parental education were differentially related to academic development, with Black-White gaps narrowing (and Black children's skills growing slightly faster) at higher income gradients but widening (and Black children's skills developing more slowly) at higher levels of educational attainment. Despite performance advantages at kindergarten entry, large baseline disparities meant that higher-income Black students underperformed their White peers by middle school, whereas Black students with better-educated parents consistently trailed their White counterparts. Taken together, these findings suggest that failure to examine how race and SES intersect to shape achievement gaps may obscure complex patterns of educational inequality.