A wide variety of diversity has become prevalent in American public schools today. Differences in gender, race, socioeconomic status, and ability levels are represented in almost all classrooms. Today's students may face the challenge of working in an environment that may not be conducive for learning. The purpose of this quantitative case study was to determine the impact of ability grouping as it relates to academic growth among an at-risk population of students. The primary research question that guided this study explored the impact of homogeneous and heterogeneous groupings on academic growth as well as the type of grouping that created a setting in which more students performed to the best of their abilities. More specifically, the type of ability grouping impacted academic growth as demonstrated on standardized tests. An urban, public elementary school was chosen for the study and proportionate sampling was used. Ten elementary emotional support students were divided into 2 instructional groups; with 5 students in each group respectively. The first group contained students who demonstrated similar math abilities and was referred to as the homogeneous group. The second group contained students who demonstrated various math abilities and was referred to as the heterogeneous group. Data consisted of quarterly standardized math assessments as well as computer generated math scores. An independent-measures t-statistics was used and revealed significantly larger academic gains for students who were grouped heterogeneously as compared to those grouped homogeneously. This study is beneficial for educators who are seeking ways to enhance student learning through cooperative learning techniques and promote positive social change in their school, district, and community.