As student achievement remains a critical discussion among federal policymakers, states, and local school districts, one response involves providing additional classroom support staff. To address deficits in mathematics education, the National Mathematics Advisory Panel (2008) urged the use of mathematics specialists (MS) to support teachers and increase student achievement through mentoring, coaching, and professional development opportunities (Association of Mathematics Teacher Educators, 2010; Berry et al., 2009; Campbell & Malkus, 2011; McGatha, 2008). This study targeted all 31 elementary schools in Unity Public Schools (UPS, a pseudonym), an urban school district in Virginia, during the 2018-2019 academic year, the last full year prior to COVID-19, a worldwide pandemic impacting all of education. This causal comparative study examined the difference in students' Virginia SOL mathematics achievement scores based on their grade level (Grades 3-5) and the presence or absence of MSs (full-time, part-time, or none). A two-way ANOVA revealed there was no statistical significance based on grade level alone, F = 1.340, p = 0.267; however, the data surprisingly uncovered an inverse dose--response showing there was statistical significance in the main effects based on the presence or absence of MSs, F = 34.054, p [less than or equal to] 0.001; more specifically, those schools with part-time or no MSs present scored higher than those with full-time MSs. These findings indicated that further examination of MSs and their effect of students' mathematics achievement scores are needed. [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.]