Students at an elementary school in urban Georgia scored below grade level in comprehension on the state's end-of-the-year assessment. School leadership implemented Lexia Core5, a blended learning program. The purpose of this quantitative study was to determine the effect of the Lexia Reading Core5 program on the reading comprehension skills of non-ELL upper elementary students performing below grade level in reading comprehension. The theoretical framework was comprised of elements of Thorndike's theory of learning connectionism and Gagne's aptitude treatment interaction because Lexia Core5 allows students to practice skills to reinforce reading development and engages students in a trial-and-error style of learning. The research questions were used to detect any statistically significant differences in the overall reading achievement scores between nonparticipants and participants of fourth- and fifth-grade non-ELL students who used Lexia Core5 intervention during the 2017-2019 school years. A Mann-Whitney U test was used to evaluate if there was a statistically significant difference between the mean analysis of the state test scores (n=8). The results indicated no statistically significant difference in the state reading scores (p > 0.05). Results may encourage positive social change in school districts by encouraging additional professional development, support, and opportunities to collaborate with peers on effectively using computer-assisted instruction. Through this instruction, educators will provide interventions that will eventually reduce achievement gaps in reading comprehension of non-ELL upper elementary students reading below grade level. [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.]