Mattering is the feeling that one's actions are significant, and that one would be missed if one were gone (Rosenberg & McCullough, 1981). So far, little research has addressed the teacher's sense of mattering in the K-12 setting. This study examined the possible foundational elements or building blocks of mattering for K-12 teachers by using exploratory factor analysis. A thorough review of the literature identified the possible elements of mattering for K-12 educators; based on that, an initial theoretical construct was designed. A survey instrument consisting of 102 items was created, and it was taken by 1,110 participants from diverse backgrounds and school demographics. The analysis revealed eight factors as the foundation of mattering for K-12 teachers: community, authenticity, flow, compensation, purpose, assimilation, job crafting, and job stability. The eight factors were categorized into three thematic units: Interpersonal (community, authenticity, and flow), Intrapersonal (purpose and assimilation), and External (compensation, job stability, and job crafting). The identification of these factors will be useful in examining some of the common problems that educators face today, including high stress levels, job dissatisfaction, and low pay. Policymakers and school leaders who understand and address the foundational elements of mattering may lead to a more positive work environment, which could, in turn, lead to higher job retention among teachers. This study serves as a starting point for future research on mattering for K-12 teachers. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]