The focus of this dissertation will be on investigating the impact of middle school mathematics tracking policies, while specifically focusing on a novel idea, called Self-Selection. Self-Selection is an intervention that provides open access to all levels of mathematics classes for students in grades six through eight. Under this program model students can self-select into advanced and double advanced mathematics courses. No prerequisites are required such as class grades, standardized test scores, or teacher recommendations. This intervention allows students and families to choose the mathematics class they feel is most appropriate. The first study in this dissertation is a systematic literature review. In this study, the researcher explored various tracking and detracking policies that are implemented in middle schools today. Along with that, the researcher identified how these tracking and detracking policies impacted students' mathematics attainment. The second study in this dissertation investigates the impact of the Self-Selection intervention on enrollments in middle school advanced mathematics classes. This article allowed the researcher to determine if the Self-Selection intervention was successful in interrupting systemic demographic trends in advanced middle school mathematics classes. Results from the first study revealed that while there is evidence of successful detracked classrooms, most middle schools still implement strict tracking policies. The first study also revealed that students' high school mathematics attainment is largely unaffected by middle school tracking and detracking policies. When students' high school transcripts were analyzed, conclusive findings show that the proportion of students enrolling in higher level mathematics classes is unchanged per tracking and detracking middle school policies. Results from the second study reveal that the Self-Selection intervention was not successful at increasing enrollments of students of color in advanced mathematics courses. These results may be attributed to a lack of additional supports put in place by the school. As some detracking policies have been shown to be successful, favorable findings are largely attributed to additional interventions that were married with detracking. In the second study, we conclude that Self-Selection did not achieve its goal; however specific changes are recommended in hopes of changing future outcomes. Overall, the results from this dissertation yielded that detracking at the middle school level can be successful if additional, and effective, supports are simultaneously implemented. Because systemic mathematics attainment trends appear to be unaltered by traditional tracking and detracking policies, this dissertation provides evidence of a novel idea that may interrupt such patterns. Again, Self-Selection would need to be adjusted to account for additional obstacles students face when choosing to enroll in advanced mathematics courses, but the idea of Self-Selection is worth further exploration. The findings of this dissertation are critical because increasing the number of students of color enrolled in advanced mathematics courses is essential to closing the mathematics achievement gap and guaranteeing that more students can successfully pursue STEM-related careers. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]