Background/Context: Nationally, almost a quarter of charter school students attend a school managed by a for-profit education management organization (EMO). EMOs have full executive authority over the operation and management of schools, including curriculum and instruction decisions. Because charter schools are funded with public dollars, critics have raised ethical issues associated with operating them for-profit. Purpose/Objective/Research Question/Focus of Study: This study compares the academic achievement of EMO-managed charter schools with other charter schools and traditional public schools in Arizona. Whereas prior EMO research has focused on total scores in mathematics and reading as the academic achievement variables, this study delves further by analyzing subtest scores that distinguish between basic and complex thinking skills. We use more sensitive test data in an effort to examine the differential impact of the educational practices of EMO-managed charter schools on academic achievement. Research Design: Student-level longitudinal test data are used for Arizona students who were enrolled in Grades 2-6 in 2001 and who remained in the same sector (EMO, non-EMO charter, or traditional public school) for the next 3 years. The test data include total scores for reading and mathematics, as well as subtest scores divided into basic and complex thinking skills. The analyses are based on a model that estimates the level of academic achievement in Year 3 using the sector of attendance as predictors and a twice-lagged achievement variable along with the other student-level covariates. Findings/Results: For students who remained in the same sector for 3 consecutive years, attendance in non-EMO-managed charter schools had a positive effect on achievement results in total mathematics. The outcome was driven by higher scores in mathematics procedures, the basic skills subtest. For students who remained in the same sector and same school for 3 consecutive years, EMO-managed charter schools exhibited a positive effect in reading vocabulary, a basic skills subtest, and a negative effect in reading comprehension, the complex thinking subtest. Conclusions/Recommendations: Previous research has illuminated many common teaching and learning characteristics of EMO-managed charter schools, such as drill and practice and standardized curricula that can be delivered by less experienced teaching staffs. Our results are the first empirical indication that the academic environments of EMO-managed charter schools may be associated with higher levels of academic achievement in basic skills at the expense of achievement in complex thinking skills, at least in reading. In all, the results are modest, but they deepen the available evidence about the academic impact of EMO-managed charter schools.