Students with intellectual disability (ID) have been participating in statewide general and alternate reading assessments during the past two decades. However, these students' reading performance on statewide assessments over time has not been adequately examined. The purpose of this study was to examine the relationship between students with ID's 5th grade reading achievement and their 8th grade reading achievement as measured by statewide standardized assessments. We used a longitudinal dataset from an urban school district in a Midwestern state in the United States. Results showed that students with ID's 5th grade reading achievement did not significantly predict their 8th grade reading achievement in the general assessment. On the other hand, students with ID's 5th grade reading achievement significantly predicted their 8th grade reading achievement in the alternate assessment. Implications of these results were discussed and recommendations for future research were provided.