As part of a Howard Hughes Program for Innovation in Science Education grant at Iowa State University, a series of interdisciplinary graduate teaching assistant learning communities (TALC) were developed. The purpose of these communities was to create an environment to facilitate teaching assistants' pedagogical development and training to enhance the implementation of inquiry experiences in the undergraduate laboratories. The TALC evaluated in this study were held for two consecutive semesters and included teaching assistants who facilitated multiweek course based research experiences in their respective STEM courses.Topics discussed during the TALC were based on the teaching assistants' concerns related to teaching this type of course. Evaluation consisted of weekly reflection responses, a pre- and postsurvey of instructional methods they consider to facilitate inquiry, pre-post definitions of inquiry-based instruction, and end-of-semester evaluations of the learning community experiences. This article outlines the development of the TALC and findings from the various forms of evaluation.