A flurry of recent research in writing studies has addressed the need for more systematic approaches to graduate-level writing support, though more research is needed into more organic models that account for graduate students' specific needs and that build infrastructure for writing support within university departments. This article reports on a graduate-level STEM Communication Fellows program at a science and engineering research university, in which graduate students in science and engineering fields help launch discipline-specific writing support in their home departments. The article begins with a discussion of program goals and departmental contexts. Then, two graduate STEM Fellows share their experiences developing support mechanisms in Earth and Environmental Sciences and Mechanical Engineering. Last, program assessment data from surveys and follow-up interviews are discussed. Findings from the STEM Fellows narratives and assessment data demonstrate different degrees of success as fellows wrestled with intricacies of the different departmental cultures. Findings also indicate the need for more structured mentoring opportunities between advanced and incoming graduate students, more focus on unstructured writing support over writing courses, and more development of asynchronous methods of peer interaction.