Despite growing up in a world that is permeated by mathematics, students graduating from US schools are woefully unprepared for the mathematical challenges that await them in the workplace or in higher educational pursuits. Mathematical competencies underpin not only success in college but also increase job opportunities for students after graduation, particularly jobs in technology, which have begun to outpace our ability to educate students and fill these positions. A close examination of Massachusetts state-mandated testing confirmed the underperformance of students in one small suburban New England school district; additional information from a recent student survey highlighted both weak computational fluency and a lack of confidence in applying conceptual understanding when solving mathematical problems. Classroom observations revealed an inconsistent teacher understanding of both math content and pedagogy. In 2015, the district hired six building-based math coaches to support teachers and students in mathematics. Recent research outlined the characteristics of effective coaching and supports collective inquiry models that fostered opportunities for reflection and building self-efficacy. After two years of building trust, facilitating collaborative conversations, analyzing data, and setting individual goals with teachers, coaches questioned if the work they were doing was having a positive impact. The proposed study aimed to examine the effects of the current coaching model; findings from the study inform the redesign and implementation of a unified structure for math coaching cycles that would focus on improved teacher pedagogical content knowledge, embedded professional development, and increased time for teachers and math coaches to work together. [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.]