Purpose: Self efficacy for clinical reasoning in physical therapists and physical therapy students is not well understood, but is becoming more important as the profession shifts to a predominately direct access environment. Higher levels of self-efficacy are associated with higher levels of clinical performance, and has been shown to be a positive predictor of performance among physical therapy, medical, and nursing students. The purpose of this study was to explore changes in perceived self-efficacy for clinical reasoning of PT students, as measured by the Physical Therapy Self-Efficacy Scale (PTSE) and to describe contributing factors to any changes, as the result of a Team-Based Learning (TBL) course. Methods/Description: This study utilized a sequential explanatory mixed method design including quantitative (survey) and qualitative (reflective narratives) data collection. Second-year DPT students were surveyed via Qualtrics™ using the PTSE, which has established construct validity among DPT students. Pre-post survey assessment occurred one week prior to the start of the course and one week post completion of the course. TBL pedagogy was utilized throughout a course designed for clinical integration of past-learned content in DPT curriculum. Reflective narratives with guided questions on contributors to perceived changes in self-efficacy were also completed as part of assignment in course. Descriptive statistics, and pre-post survey comparisons via paired t-test based on Shapiro-Wilk results were calculated via SPSS version 25 for quantitative analysis and grounded theory approach for qualitative data. Results/Outcomes: Sixty-three percent (28/44) of the students participated in both pre and post surveys and reflective narratives. PTSE mean scores for pre and post survey were 18.03 (+/- 2.01) and 20.62 (+/- 1.80), respectively. Paired t-test revealed significant differences, P<.001 between total PTSE score and all individual questions. Five themes were identified: confidence, curriculum, prioritization, reflection, and personal traits as contributors to the potential changes in clinical reasoning self-efficacy. Conclusions/Relevance to the conference theme: The results of this study demonstrate an increase in clinical reasoning self-efficacy among second-year physical therapy students following a semester of TBL activities. Changes in perceived self-efficacy are explained by several factors including confidence, curriculum, prioritization, reflection, and personal traits. Because self-efficacy is responsive to environmental inputs, it is proposed that a complex interaction of these factors resulted in the observed increase in PTSE scores. These results support the need for continued development of learner-centered and active learning pedagogies in DPT curriculum, fostering the skills needed for future healthcare professionals to interact in complex healthcare environments.