In September, 2016, the National Center for Special Education Research (NCSER) and the National Center for Education Research (NCER) of the Institute of Education Sciences (IES) convened a group of experts to discuss and provide input on research needs in the area of middle and high school writing for students, including English learners (ELs) and those with or at risk for disabilities. The discussion focused on four topic areas: (1) argumentative writing, (2) support for struggling writers, (3) engaging adolescents in writing, and (4) assessment and feedback. Each session consisted of a brief review of the topic and introductory questions, presenter remarks, and general discussion. The meeting concluded with each expert identifying the most critical research need from his or her viewpoint. This report summarizes the key points and themes that emerged from the presenters' remarks and discussion.