The purpose of this study was to investigate the impact of inference making, decoding, memory, and vocabulary on reading comprehension among 7th- through 12th-grade struggling readers with varying levels of inattention and hyperactivity. We categorized a group of 414 struggling readers into 3 groups based on results from factor mixture modeling: (a) low inattention + low hyperactivity, (b) high inattention + high hyperactivity, and (c) high inattention + low hyperactivity. Results indicated that vocabulary and inference making, but not decoding, predicted reading comprehension outcomes among all 3 groups of struggling readers. Working memory predicted reading comprehension among struggling readers in the low inattention + low hyperactivity and high inattention + high hyperactivity groups.