The Puerto Rico Collaborative for Excellence in Teacher Preparation (PR-CETP) is a five-year project involving seven institutions of higher education in Puerto Rico in a collaboration to reform their science and mathematics teacher preparation programs. In these five years, PR-CETP developed multiple strategies and pilot projects aimed at improving the teacher preparation curriculum, through the development of faculty who teach preservice science and mathematics courses, support for preservice students from recruitment into the program through induction into teaching, and assessment and evaluation processes. A Follow-On Evaluation Project is assessing the impact the project has had on several key aspects: institutional policies, faculty who teach the preservice courses, and the new mathematics and science teachers who were involved in the PR-CETP project. The impact of the PR-CETP on new teachers will be studied in relation to their level of participation in the reform efforts. The assessment/evaluation methods include surveys, classroom observation protocols, conceptual understanding examinations and portfolios, and the assessment of the conceptual understanding of the new teachers' students. The project is collaborating with the CETP Core Evaluation effort.