The problem investigated in this study is that U.S. minority and low socioeconomic status (SES) student participation in advanced academic classes continues to lag behind that of Caucasian and economically advantaged students. The purpose of this project study was to investigate the participation gaps between minority and low SES students compared with non-minority and high SES students in advanced mathematics courses in the study district's middle school. The theoretical framework for the study was gap-analysis theory. A quantitative gap analysis of existing student test score data was conducted, utilizing a secondary analysis of existing Iowa Test of Basic Skills data from 347 middle school students, with 196 students classified as low SES and 129 as minority. Descriptive statistics and 2 one-sample chi square tests were used to examine differences by ethnicity and SES subgroups and to test whether the distributions of students who met the district's 70th-percentile cut-score were different than the hypothesized distribution of equal proportions. The results demonstrated significant enrollment gaps between minority and low SES students versus non-minority and high SES students. The study findings informed a policy recommendation project that offered suggestions for the current mathematics testing and enrollment program at the study site. Implications for social change include providing research-based findings to the administration at the local site on the enrollment gaps for minority and low SES students which may inform future decisions about enrollment policies for advanced mathematics courses.