Graduate teaching assistants (GTAs) are crucial facilitators of undergraduate education, yet many begin their teaching appointments with minimal knowledge of teaching practices. Chemistry Instructional Coaching offers GTAs at the University of Michigan an opportunity to develop their instructional practice through a collaborative, nonevaluative, and reflective coaching program. We implemented an instructional coaching program designed in collaboration with the Knowles Teacher Initiative to meet the needs of GTAs teaching in a postsecondary setting. In a coaching cycle, a trained GTA (the coach) guides a recruited GTA (the coachee) through conversations that allow the coachee to develop a teaching-related goal, plan how to implement changes to their instruction, and reflect on the measurable outcomes. This iterative cycle builds on itself over the course of one or two semesters, with new goals being identified for each cycle. Through adapting the program in our department over time, we utilized feedback from coaches and coachees to adjust the structure of the coaching program and develop relevant materials to support knowledge of instructional practice. Herein, we report on the program design, enrollment, and current structure, and we discuss the main adaptations that we implemented to develop a sustainable program within the chemistry department. We believe that this graduate-student-led instructional coaching program has the potential to be integrated into other departments or postsecondary settings.