Assessments developed and field tested for the mainstream student population may not be accessible for students with disabilities (SWDs) as a result of the impact of extraneous variables, including cognitive features, such as depth of knowledge required, grammatical and lexical complexity, lexical density, and textual/visual features. This study investigates the impact of these features on the performance outcomes of SWDs in the United States. Live test items from two different states with large numbers of SWDs were evaluated for their level of depth of knowledge features, linguistic complexity, two types of lexical features, and textual and visual characteristics. Results suggest that textual features have the greatest impact on the performance of students with different types of disabilities. (Contains 5 tables and 2 notes.)