In 2010, the U.S. Department of Education (the Department) contracted with Synergy Enterprises, Inc. and edCount, LLC, to complete a study titled Language Instruction Educational Programs (LIEPs): Lessons From the Research and Profiles of Promising Programs. This study includes a review of the foundational literature related to LIEPs, case studies of 20 school districts with well-designed and well-implemented LIEPs, and a Lessons from the Field guide that integrates findings from the literature review and the case studies and provides practical information for local educators on selecting, designing, implementing and evaluating LIEPs. This literature review is intended to lay a foundation for the LIEP study. It provides literature-based summaries for a range of topics that may factor into LIEP designs and functions, and supports school districts in their decisions about how to choose appropriate LIEPs for their students' needs. The review summarizes critical ideas, findings, concepts, debates and practices that populate the literature on LIEP design, implementation and evaluation at present. Literature Review Search Terms and Research Questions are appended. (Contains 19 exhibits and 17 footnotes.)