ABSTRACT Online cohort graduate programs in education offer science teachers opportunities to enhance their knowledge and professional practice alongside a cohort community of educators without interrupting their careers or adversely affecting their personal lives. While it is understood that online cohort graduate programs can create robust professional communities, their impact on sustained pedagogical change for teachers is not fully understood. This research, based on a qualitative study of an asynchronous online Master of Education cohort program in Science Education, investigates its impact on K-12 teachers’ pedagogical attitudes, understandings, and practice. Focus groups were conducted with thirty teachers from two program cohorts. Findings suggest that through research exploration and collaborative culture, participating science teachers felt educated, supported, and empowered to make sustained pedagogical improvements within and across their educational contexts. This study contributes to the understanding of the potential of online cohort graduate programs in science education in fostering pedagogical transformation and can inform the design of similar programs.