Kindergarten teachers in one large district in Arkansas are inconsistently implementing science, technology, engineering, and mathematics (STEM)-integrated lessons into their curriculum despite a systemic plan for increasing equitable access to high-quality STEM-focused education for all students by the state department of education. While researchers suggest that barriers for lower elementary teachers in implementing STEM include low STEM content and pedagogical efficacy, few studies explore how kindergarten teachers implement STEM lessons with their students. Hence, the purpose of this descriptive-interpretive study was to explore Arkansas teachers' experiences with and perspectives on implementing STEM lessons in their kindergarten classrooms within the context of the Arkansas (AR) STEM Model Program. This study, framed by Bandura's social cognitive theory and constructivism, was driven by research questions focused on exploring kindergarten teachers' perceptions of how they currently implement STEM-integrated learning and their successes and challenges in doing so. Interviews were conducted with 12 kindergarten teachers. Data were analyzed thematically with open and axial coding techniques. The results of this study indicated that various factors influence how consistently STEM lessons are integrated into these classrooms. Outside factors, such as a limited amount of curriculum, administrative support, professional training, and internal influences, such as self-efficacy and knowledge, influenced how often STEM was implemented. The results of this study could influence teacher professional development and encourage necessary shifts in curriculum development to better meet the needs of students and provide them with opportunities to develop essential 21st-century skills. [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.]