The most frequent requests for accommodations made by students with learning disabilities at the postsecondary level are for the provision of testing accommodations. Yet, to date minimal research has been conducted to investigate the degree to which these accommodations impact the performance of those students who use them. The goal of this study, therefore, was to provide empirically based insight into the effects of testing accommodations on individual student performance. The study took place at an urban Community College, an open admission institution that serves a diverse population of students with disabilities. Ten students with documented reading disabilities participated in the study. All participants were registered with the College's Disability Resource Center and were determined to be eligible for audio-tape format and extended-time testing accommodations. A variant ABAB reversal research design was used to examine the impact of these testing accommodations on the reading comprehension test performance of each participant. The data were analyzed to discern the intra-subject performance outcomes demonstrated by students under specific testing conditions. Further analysis took place to examine the inter-subject variability demonstrated among the 10 participants in relation to the specific testing conditions. The study results corroborate findings being reported by researchers investigating the impact of testing accommodations on students with reading disabilities in secondary levels of education. The data strongly support the overall conclusion that although the main and or interactive effects of audio-tape format and extended-time are found to benefit some students with learning disabilities some of the time, neither of these accommodations, singularly or packaged, benefit all of the students all of the time. The findings further evince the negative, positive, and null effects that accommodations can have on individual test performance thereby validating the empirical assumption of heterogeneity in response to test accommodations among students with learning disabilities who use them.