This article describes the developmental patterns of Hispanic-White math and reading achievement gaps in elementary school, paying attention to variation in these patterns among Hispanic subgroups. Compared to non-Hispanic White students, Hispanic students enter kindergarten with much lower average math and reading skills. The gaps narrow by roughly a third in the first 2 years of schooling but remain relatively stable for the next 4 years. The development of achievement gaps varies considerably among Hispanic subgroups. Students with Mexican and Central American origins--particularly first- and second-generation immigrants--and those from homes where English is not spoken have the lowest math and reading skill levels at kindergarten entry but show the greatest achievement gains in the early years of schooling. (Contains 5 tables, 10 figures and 20 notes.)