Experience in the workforce influences teacher educators' responses to professional development efforts for adapting new practices. This study examines trajectories of novices and experienced teacher educators in a three-year longitudinal professional development community focused on infusing thinking into college teaching. A four-stage trajectory model for development was used to track changes in practice among the teacher educators. The authors' analysis identified three distinct patterns of professional development among teacher educators: one characterizing novice teacher educators and two distinct patterns for the experienced group. While novices exhibited openness toward learning, the experienced teacher educators were divided into one group that revealed an inquiry stance examining their practice and a second group that claimed expertise and was less willing to consider changing instructional practice. This initial differentiation at the first trajectory stage led to distinctions in development at later stages, resulting in a reclassification of the educators into three groups: novices, experienced experts, and experienced non-experts. These findings emphasize the importance of teacher educators' years of experience, attitude towards inquiry, and self-perception of expertise as critical determinants of successful educational reform.