This study addresses a problem of practice in a suburban school district in the Northeast United States. Data showed that students identified as Multilingual Language Learners or English Language Learners (MLLs or ELLs) were more likely to be referred to special education than their English-speaking peers. Research suggests that boosting teacher efficacy in supporting MLLs and ELLs in a general education environment can reduce their disproportionate representation in special education. After engaging in a root cause analysis, a Professional Learning Community (PLC) for teachers in early elementary grades engaged in data inquiry and an Improvement Science Plan-Do-Study-Act cycle. Data was collected to analyze teacher reactions to the intervention, changes in teacher behavior, and changes in student learning. Preliminary results suggest that this intervention was positively received by teachers and increased teacher-reported efficacy for teaching MLLs and ELLs. [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.]