The present study examined growth in writing quality associated with feedback provided by an automated essay evaluation system called PEG Writing. Equal numbers of students with disabilities (SWD) and typically-developing students (TD) matched on prior writing achievement were sampled (n = 1196 total). Data from a subsample of students (n = 655) was used to investigate evidence of transfer to improved first-draft performance on a follow up writing prompt. Three-level hierarchical linear modeling was used. Findings indicated that SWD produced first drafts of lesser quality than TD students, but grew at a faster rate and were able to close the gap in writing quality after five revisions. However, these effects were moderated by school quality and the availability of internet-connected devices in schools. There was no evidence of transfer for either group of students. Results document a positive association between the use of PEG Writing and growth in writing quality for SWD, and underscore the importance of having sufficient technology resources for maximizing this growth.