The Common Core State Standards (CCSS) in ELA/literacy call for increased rigor, close reading of complex texts, evidence-based argumentation in academic English, and collaborative conversations. For English language learners (ELLs), achieving the standards requires that they double their efforts to simultaneously learn both academic English and content. For ELLs to be successful, they need highly qualified teachers; however, many teachers feel unprepared to implement the standards for both content and language for ELLs. Using a dual theoretical framework that included social constructivism and academic language, this study sought to understand how teachers experience the instructional shifts from the earlier California standards to the CCSS, especially as they relate to working with ELLs. Using the Interpretative Phenomenological Analysis methodology, this study engaged seven participants in three semi-structured interviews. The findings indicated six major themes, including: earlier mandates were constraining and left teachers open to the CCSS; teachers viewed the CCSS as an opportunity to build students' competence; teachers needed more preparation for the instructional shifts; teachers experienced greater satisfaction with the instructional shifts; teachers described improved student engagement with the CCSS; and teachers experienced success teaching ELLs the CCSS. This study concludes that teachers' experiences of the shift to the CCSS was primarily positive and provided superior learning opportunities for the ELLs with whom they worked; however, teachers initially felt unprepared for the shifts, particularly with ELLs, and were uncertain how they and their colleagues should make the shift to the new standards. [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.]