The Houston Independent School District (HISD) has provided prekindergarten classes for Houston area four-year old students since the 1985-1986 academic year. The focus of the program has been beginning literacy and oral language development that support individual needs as well as the language and cultural backgrounds of children. The central feature of the program has been communication and literacy that form the basis of children's future academic success. There are two main HISD prekindergarten program models: Early Childhood Centers and school-based programs. The vision of the HISD Early Childhood Centers initiative is to serve as a model for the district by providing a comprehensive state-of-the-art preschool program. The purpose of this evaluation was to assess the impact of two HISD prekindergarten class models on students' performance on the 2012-2013 Stanford and Aprenda reading and mathematics subtests. The most notable findings of this evaluation were: (1) There were no statistically significant differences in the mean Normal Curve Equivalent (NCE) scores on both 2012-2013 kindergarten Stanford and Aprenda reading and mathematics subtests between students who attended Early Childhood Centers and their peers in school-based programs; and (2) At the student group level, the results show that the performance of Early Childhood Center students and school-based program students on both 2012-2013 kindergarten Stanford and Aprenda reading subtests were comparable in all student groups (ethnicity, gender, economically disadvantaged, special education status, limited English proficiency (LEP), and at-risk). However, the results show that the non-at-risk students who attended the Early Childhood Centers outperformed their school-based program peers on the Stanford mathematics subtest.