Drawing on data from a writing program in English as a second language (ESL) at a large university in the midwestern United States, this article addresses the significant gap in programmatic and pedagogical responses for graduate writing support by probing the notion of ESL service courses that approach graduate writing courses as being essentially the same as undergraduate writing courses. It looks into the teaching of writing and writing instructor training in TESOL by tracing the complex phenomenon by which first-year students in a master's in teaching English as a second language (MATESL) program--both native and nonnative speakers who do not have any experience of teaching let alone writing--become instructors of ESL graduate writing courses in which many doctoral students are enrolled. It raises questions about ESL practitioners' assumptions about the transfer of writing skills across disciplines and genres and examines the implications of English for academic purposes pedagogy for graduate students' writing practices. This article aims to prompt critical reflection on, and ultimately innovation in, writing programs designed for international graduate students while contributing to the development of a meta-disciplinary awareness of the study of ESL writing in TESOL.