Language immersion education (with various related approaches called bilingual and dual-language education) is a complex topic that includes many different linguistic, educational, social, and political facets. There has been much debate about the best method with which to educate children in a language that is not their mother tongue. While the goal of language immersion education is to immerse a child in the second language, in order for the child to be bilingual there must remain a support system for their first language. Many researchers have sought to determine the best way to achieve these two goals, to gain a second language while also maintaining and enhancing a child's home language. The results of these studies are diverse, but findings from second language acquisition research can help to create conditions for successful language immersion education. While it is by no means exhaustive, as new studies are being published everyday, this synthesis of language immersion research and pedagogical models, drawing primarily on research focusing on K-5 French immersion education in the U.S. and Canada, hopes to provide a clear overview of research-informed approaches for language immersion education in the North American context.