Students' instructional needs are identified, and proper interventions and instructional placement are put in place to maximize student-learning potential, but there is a gap in literature regarding the impact of classroom factors on student achievement of English learner (EL) students in diverse elementary schools (Heritage, Walqui, & Linquanti, 2020). The problem involved identifying the impact of intervention type, mobility status, and language of instruction on academic achievement of fifth grade EL students. The purpose of this quantitative study was to examine the impact of classroom factors on student achievement of EL students in elementary schools in the large urban school district in Southeast Texas. Data were obtained from the Chancery System, for data regarding student information and individual state standardized testing scores, and the Intervention Assistance Team (IAT), for data regarding student level of intervention, mobility status, and language of instruction. A three-way ANOVA showed whether the three independent variables significantly differentiated from the State of Texas Assessment of Academic Readiness (STAAR) math, reading, and science achievement test scores of students and whether the three-way interaction of the independent variables had defined a difference in the STAAR achievement test scores. The results of the analyses determined that the math, reading, and science STAAR scores differed based on individual effects as well as the interactions of intervention tier, language of instruction, and mobility status. The results showed significant evidence to reject the three null hypotheses posed in the study. Educational leaders and policymakers should explore potential interventions they could implement to encourage continuous enrollment for EL students considered high-risk for increased mobility. Future researchers could build on this study by exploring the same variables and their influence on reading, math, and science scores among EL students in middle school or high school or from suburban or rural school districts. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]