Reading research indicates a student's academic achievement is connected to his or her reading ability (Tindall & Nisbet, 2010). Children do not have sufficient reading skills because they lack the literacy skills necessary to be successful readers. These fundamental areas include phonics, reading comprehension, fluency, alphabetic awareness, and phonemic awareness (Tindall & Nisbet, 2010). The purpose of the proposed quantitative, quasi-experimental study was to determine to what effect, if any, RTI supplemental reading instruction and a parent component, in addition to core curriculum direct instruction, has on student reading achievement. In the study, data for third-grade students' scores on DIBELS, as well as from a 5-point Likert-type survey completed by the students' parents, was collected. A one-tailed "t"-test and a one way ANOVA was conducted to determine whether there was a difference in reading scores of the two groups prior to the intervention. The Likert-type responses for the parent-survey questions was analyzed to determine parents' perceptions of their third-grade students' reading skills based on the parents' working with their students at home. The study results indicated the supplemental instruction, along with the core curriculum, resulted in a significant difference between the pretest and posttest scores for the class that received instruction with the DI core curriculum with RTI and the parent component and the class that received only the DI core curriculum. The mean results from the nine question survey revealed that the parent home component was effective for those who used it. Recommendations for professional development opportunities for all teachers, paraprofessionals, parents, and administrators involved in the RTI process and the use of the parent home component program were made based upon the analyzed data from the research study. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]