The present study examined Latinx school readiness and 3rd grade student achievement, considering differences based on social categories of gender, race, ethnicity, and home language. The sample included 683 racially diverse children (M[subscript age] = 4.94; SD = 0.57) of Dominican- or Mexican-origin from Spanish-English or Spanish-only proficient homes. Baseline data included a test of school readiness and mother and teacher ratings of behavior. Follow-up data included the 3rd grade New York State test. Results show that 74% of Latinx children were not proficient in 3rd grade reading, with boys and children from Spanish-only homes less likely to be at grade level. School readiness predicted achievement for all groups. On the whole, Latinx students, and especially boys and non-English speakers, appear to be marginalized in U.S. public education systems.