This Work in Progress Paper presents the creation of a codebook that will support a broader study focused on understanding the experiences of veterans with service-connected disabilities as they transition from the military into an undergraduate engineering program. Military careers and engineering student life have stark differences. This exploratory research study aims to develop a deeper understanding of the experiences of engineering student veterans with service-connected disabilities as they transition into higher education. To investigate these transitions, we utilized semi-structured narrative interviews with three sophomore engineering students with disabilities. The participants were purposively selected for maximum variability across particular demographic characteristics. In this thematic analysis, we explored the rich narratives of the students' transitions from military members to undergraduate engineering students by coding the data and organizing the themes as they mapped to the Schlossberg Transition Theory. Further analysis of the data resulted in a codebook consisting of eight codes - two referring to one's self, three that characterize the transitional situation, one aligned with effective social support, and two codes denoting strategies these student veterans use to overcome the unique challenges associated with their transition from military member to engineering academic. The codebook will be presented in this paper.