Preservice teachers engage in clinical experiences with in-service teacher mentors to observe and apply theories being learned in coursework in classroom settings. Among the obstacles with clinical experiences is that mentor teachers may lack knowledge of theories being practiced by preservice teachers and may struggle to provide mentorship supports. This convergent mixed-method study engaged four undergraduate student researchers in exploring how a clinical-based course supports the development of the preservice teacher and how professional learning and mentoring experience support the development of the in-service mentor teacher. Findings indicate increases in knowledge and applications of PBI for preservice teachers and mentor teachers and increases in confidence from the in-service teachers to serve as mentors.