Purpose: In this study, the authors evaluated the contribution made by dialect shifting to reading achievement test scores of African American English (AAE)-speaking students when controlling for the effects of socioeconomic status (SES), general oral language abilities, and writing skills. Method: Participants were 165 typically developing African American 1st through 5th graders. Half were male and half were female, one third were from low-SES homes, and two-thirds were from middle-SES homes. Dialect shifting away from AAE toward Standard American English (SAE) was determined by comparing AAE production rates during oral and written narratives. Structural equation modeling evaluated the relative contributions of AAE rates, SES, and general oral language and writing skills on standardized reading achievement scores. Results: AAE production rates were inversely related to reading achievement scores and decreased significantly between the oral and written narratives. Lower rates in writing predicted a substantial amount of the variance in reading scores, showing a significant direct effect and a significant indirect effect mediated by measures of oral language comprehension. Conclusion: The findings support a dialect shifting-reading achievement hypothesis, which proposes that AAE-speaking students who learn to use SAE in literacy tasks will outperform their peers who do not make this linguistic adaptation. (Contains 8 tables, 2 figures and 2 footnotes.)