This report compared the academic achievement of prekindergarten students who were enrolled in Houston Independent School District (HISD) early childhood centers (ECC) during the 2015-2016 school year to their peers who attended school-based programs. Academic achievement was measured on the HISD CIRCLE English and Spanish language, literacy, and mathematics subtests. Key findings include: (1) The overall increase of student's ages 3.5 to < 4.0 years old who achieved proficiency in English and Spanish language, literacy, and mathematics was typically higher from the middle-of year (MOY) to end-of-year (EOY), regardless of prekindergarten program attended; (2) The overall increase of student's ages 4.0 years and older achieving proficiency in English and Spanish language, literacy, and mathematics was typically higher from the beginning-of year (BOY) to MOY for students who attended an ECC; (3) A positive, statistically significant relationship was found between students' BOY total score and their proficiencies in language, literacy, and mathematics by the EOY regardless of age group and language version of the subtests administered; and (4) Prekindergarten program type was observed to predict proficiencies in language, literacy, and mathematics for students ages 4.0 years old and older, regardless of language version of the subtests. Recommendations include: (1) The Early Childhood Department may want to identify and monitor factors that impact the educational experiences of students once they enroll in HISD Pre-K programs to provide further insight as to why 3.5 to < 4.0 year-old students were more likely to achieve higher proficiency in language, literacy, and mathematics at a school-based program (SBP), in contrast to 4.0 to < 4.5 year-old and 4.5 or above year-old students were more likely to achieve higher proficiency if they attended an early childhood center (ECC); (2) The Early Childhood and Research and Accountability departments may want to monitor the academic growth and achievement gaps of students in the context of demographic characteristics and content area; and (3) The Early Childhood Department may consider working with the Student Assessment Department, Special Education Department and/or Research and Accountability Department to identify and implement with fidelity an inclusive, monitored assessment to measure all children's strengths, progress, and needs upon entering and exiting HISD prekindergarten programs.