Many middle school students with disabilities struggle to read fluently and express comprehension of entire passages. This is because they comprise a population of students who continue to struggle to quickly and accurately read single words in isolation, also known as word recognition automaticity. These students often have struggled for several years with word recognition automaticity, which then affects their reading self-efficacy. Middle school students with disabilities need interventions that increase word reading fluency and increase self-efficacy. The Lexia PowerUp© Literacy Program may be a viable intervention to assist in increasing both skills. This quasi-experimental one-group pretest/posttest design aimed to examine the extent to which the Lexia PowerUp© Literacy Program increased word recognition in middle school students with disabilities, thereby also potentially increasing their reading self-efficacy. Middle school students with disabilities were given the Lexia PowerUp© Literacy Program within their Language Arts classes in increments of 30 minutes 3 times a week for 12 weeks (1080 total minutes). A comparison of one-sample paired t-tests from pre- and post-intervention assessments of the "Word Recognition Fluency" subtest of the "KTEA-3" determined that the Lexia PowerUp© resulted in a significant gain in the students' word recognition automaticity. A separate pre- and post-intervention assessment using the "Reader Self-Perception Scale-2" was also completed by the same students. While self-efficacy levels did increase after the intervention overall, it was not significantly. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]