The purpose of this study was to determine which of four Response to Intervention (RTI) programs, System 44, Read 180, Lexia Reading Core5, or Read Naturally, was most effective for alleviating phonics and phonemic awareness reading deficits in students struggling to read fluently and comprehensively. The problem related to this research is that students are progressing from one grade-level to the next without the ability to read proficiently. This study examined 75 fourth-grade students from a Tennessee public school. The research utilized a quasi-experimental research design and ran a Welch ANOVA and Games-Howell post hoc analysis to determine the most accurate results. Based on the Welch ANOVA, one of the intervention programs was effective. Following the Welch ANOVA, the Games-Howell post hoc analysis showed that Read 180 was effective for alleviating struggling students' reading deficits and raising end-of-year English/Language Arts (ELA) scores. Results also showed that System 44, Lexia Reading Core5, and Read Naturally were not effective intervention programs for this population. With System 44 being the correlating perquisite to the Read 180 program, the results, surprisingly, did not show any significant gains for students enrolled in this intervention. Lexia Reading Core5 resulted in scores which almost closed the knowledge gap, however, Read 180 proved the more effective program. [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.]