This mixed-methods study examined the factors contributing to teachers' self-efficacy in teaching for conceptual understanding and investigated the impacts of a targeted intervention on their self-efficacy to work toward all students having equitable access to teaching that builds their conceptual understanding. This three-manuscript dissertation discusses the theoretical framework, the major findings identified in the data, and the impacts of the study on future practices. Manuscript 1 includes a thorough review of the literature to examine this problem on a wider scale, as well as two local needs assessments to examine the problem at the meso-level. Manuscript 2 examines the problem of practice, significance for educational equity, and provides a refined theory of in addition to reporting the study results. Manuscript 3 provides a summary and in-depth reflection of the dissertation process, including the improvement approach, the role of leadership in educational equity work, as well as next steps for future research and improvement. [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.]