A modified extensive reading literacy intervention was examined in this study. The problem was English Learner third and fourth-grade students reading standardized tests scores were low and educators were uncertain as to which type of intervention was best to improve English Learner student oral reading fluency and reading comprehension. This problem has negatively impacted English Learner students, teachers, and schools because of strict accountability requirements. If the problem was not addressed, educators would continue to focus their reading interventions on highly structured componential reading skills which do not impact reading fluency or reading comprehension and reading test scores would continue to be low. The purpose of this quantitative ex post facto two-group comparative quasi-experimental study with pre- and post-test design was to examine if a modified extensive reading intervention program was associated with improved DIBELS and SRI scores compared to students who did not engage in a modified extensive reading intervention. The research methodology derived from Allington (2014). A total of 104 Spanish speaking students with various WIDA levels participated in the study. Two research questions were presented in the study. Results indicated a statistical advantage for the comparison group regarding reading fluency and a slight increase in reading comprehension; however, homogeneity of variances between groups was not found for student language proficiency level which may have impacted results. A large effect size for student DIBELS growth was found (intervention group 0.82; comparison group 1.01) and a small effect size for student SRI growth was found (intervention group 0.38; comparison group 0.42). Educators can be assured that reading volume does impact student literacy. A future recommendation would be a call for more extensive reading studies, especially at the elementary 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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]