The problem addressed in this study was low student achievement among students from underrepresented student groups. In this quasi-experimental research study, the self-efficacy theory was utilized to examine the relationship between teachers' receipt of instructional coaching and student achievement scores. The purpose of this quasi-experiment was to use a series of independent sample t-tests to determine if a statistically significant difference existed between the mean achievement scores of diverse students instructed by novice and veteran teachers who had received instructional coaching support. Student achievement data was collected from the participating school district's third-grade students' State of Texas Assessments of Academic Readiness tests administered during the Spring of 2021 and 2022. The results showed that only the White student group exhibited a significant difference in both achievement scores. Overall, data demonstrated trends of greater student achievement for students with teachers who were veteran in receiving instructional coaching support. [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.]