Extended time to complete course examinations is the most commonly provided accommodation to students with disabilities in postsecondary institutions. However, there is a paucity of studies that examine the use and influence of extended time in true testing situations. The present study examined test accommodation used by 596 students with disabilities at a large research university. These students completed a total of 3,726 exams in 1,517 unique courses. Results indicated that extended time was used in approximately half of the tests, and of these, a nearly there was an even split between the use of less than and more than 50% additional time. In a statistical model predicting whether a participant used extended time at least once in a course, having a learning disability, having attention-deficit/hyperactivity disorder (ADHD), and taking a science, technology, engineering, and mathematics (STEM) course were statistically significant predictors of whether a participant used extended time in a course. Implications and areas for future research are presented.