Students in grades 5-9 (N = 29) with specific learning disabilities (SLDs) (dysgraphia, dyslexia, or oral and written language learning disability, OWL LD) were asked to take notes and handwrite or type summaries of social studies texts about world geography and cultures that they read or heard. This activity required activating knowledge of academic language for the disciplinary content. Fine-grained analyses of their spelling errors focused on the phonological, orthographic and morphological aspects of word spelling affected while writing in an academic register. Nonparametric statistical analyses revealed no significant differences attributable to SLD diagnosis or combinations of the mode of the source text (reading or listening) and transcription (handwriting with stylus or typing with keyboard). Students generated similar degrees of error complexity in their spelling errors when writing in this disciplinary academic register regardless of the nature of their SLD, mode of presentation of source texts, or mode of transcription. Three types of common misspelling patterns across SLDs, mode of presentation, and mode of transcription are described in this exploratory study. Instructional applications for teaching students with SLDs to spell words in English, a morphophonemic orthography, when composing in an academic register are discussed as well as proposed future research directions.