As students gain access to personally-owned Mobile Communication Devices (MCDs), schools have begun to embrace MCDs as mobile-learning (m-learning) teaching and learning tools. A research gap currently exists for the innovation of m-learning with student-owned devices, which this study attempts to fill by answering the following Research Question: What are the Bring Your Own Device (BYOD) Levels of Use of teachers at a high-performing, high SES suburban high school? To answer this question, I answered 5 sub questions: (1) What instructional decisions did BYOD user-level teachers make with regards to m-learning? (2) How did teachers collaborate on BYOD with colleagues during implementation? (3) How did teachers participate in voluntary professional development for BYOD and m-learning? (4) Was there a difference in Levels of Use between early career and veteran teachers? (5) What barriers to successful implementation did teachers at this school report? To answer these questions, I conducted a Levels of Use interview with 2-3 teachers from each academic department (n=28), at a school that was in its third year of BYOD implementation, as well as observed 18 of the teachers during instruction. I triangulated data from a first and second interview with observation data, and analyzed these data sets to profile the different Levels of Use among the teachers, and present recommendations for research and practice. I rated all participants between Level 0: non-use and Level IVB: refinement; no teachers in this study were above Level IVB. The findings indicate that teachers made instructional decisions based on their Level of Use, and although they did not participate in ongoing professional development specific to BYOD, they did work with others based on their Level of Use. Few teachers participated in voluntary professional development, and cited time as a factor. This study also finds that personal experience with technology and lesson planning for student-centered learning is a greater indicator of successful BYOD implementation than age or teaching experience. Finally, the most commonly reported barriers to successful implementation of BYOD were time, equity/access, and student behavior. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]