This study investigated shifts in preservice teachers’ perceived preparedness, readiness to engage in the profession, and teaching self-efficacy before and after a culminating field experience within a two-year, master’s level initial teacher education program at a large Australian university. Employing the Pre-service Teacher Professional Experience (PTPE) scale, we examined pre-service teachers’ pre- and post-field experience changes for each construct. We then used structural equation modeling to test a hypothesized causal framework, confirming theorized relationships among preparedness, readiness to engage, and self-efficacy for teaching. Path analyses revealed significant shifts in how specific dimensions of preparedness contributed to preservice teachers’ readiness to engage in the profession, which, in turn, influenced their teaching self-efficacy. Findings support the utility of the PTPE and causal framework in future research on teacher preparation, particularly as a means for teacher education programs to assess pre-service teacher development in alignment with professional standards for teaching.