Descriptive and qualitative research was used to explore teacher training, teachers' perceptions, and instructional practice for writing in inclusive middle school science (n = 22) and social studies (n = 27) classrooms. Data sources for the two parallel studies included questionnaires and interviews with 49 participating teachers as well as four observations within each teacher's class during content-area writing instruction, resulting in a total of 196 class observations. Teachers reported during interviews that special education teacher (or paraprofessional) support for students needing small group or individualized instruction and adaptations was essential for enhancing writing for students with disabilities. Teachers' responses during interviews and classroom observations corroborate findings that tools including graphic organizers and guided notes were commonly used and are beneficial for all students in their inclusive content classrooms. Findings suggest a need for increased pre- and in-service teacher training and professional development for how to strategically teach and incorporate additional writing instruction, beyond writing notes and short responses, into science and social studies classroom instruction. This article concludes with considerations for future research, professional development, and teacher preparation to support knowledge development and content-area instruction in written expression.