For decades, researchers examined the "achievement gap" between minority and nonminority students. This singular definition of "achievement gap" ignores important within-group differences. This article uses National Education Longitudinal Study (NELS:88) data to examine within-group differences and compares those across Latino, African American, and White populations. Results question the singular definition of "achievement gap." Given the importance of how issues are defined, a singular definition of "achievement gap" may mean current policies miss the mark in raising achievement levels between and within groups. (Contains 6 tables.)