Professional development is a central piece in the continuing education of teachers. The purpose of this study was to examine professional... Show moreProfessional development is a central piece in the continuing education of teachers. The purpose of this study was to examine professional development for teachers, in particular, the impact of one program that has the potential to positively influence educators as their careers evolve. Twenty-seven teachers who served as participants in the National Science Foundation (NSF) Graduate STEM (science, technology, engineering and mathematics) Fellows in K-12 Education Program (GK-12) volunteered to be interviewed about their experiences as teacher partners with graduate student Fellows who were considered experts in their content area and research methods. The teachers taught 1st through 12th grades in 22 different schools, and represented nine GK-12 programs in six states. The data collected in this qualitative study indicate enduring impacts on teachers and those included: affective impacts, as well as impacts on their practice, their colleagues and their professional involvement. In addition, Fellow and student impacts were reported. The teacher reports indicate that the design and goals of the GK-12 program—which is meant to impact graduate student Fellows, teachers and students—are consistent with the literature on best-practice professional development including facilitating teacher change. Thus, this program can serve as a model for designing effective professional development. A limitation of this study is that most of the data collected were from teacher reports. Ph.D. in Science Education, July 2012 Show less