The authors examined the effects of a long-term, continuous professional development (CPD) model, designed to support teachers to enact Project-Based Learning (PBLSAT). How do novice PBLSAT teachers view their acquisition of PBLSAT skills and how do expert PBLSAT teachers, who enacted the program 5–7 years, perceive the program? The authors suggest that the CPD model helps teachers develop a sense of personal ownership and customization for the program, through multi-staged support to integrate student free-choice PBL into the formal science curriculum.