Effective biliteracy education for young dual language learners (DLLs) is an important equity concern both in California and across the nation. In California, over 60 percent of children under the age of five are DLLs – children who reside in homes where languages other than English are spoken. As public Transitional Kindergarten (TK) programs expand and a focus on early foundational literacy skills gains prominence, it is essential to prioritize research on early language and biliteracy development for young DLLs. This brief, written by Dr. Elizabeth Alvarado, considers best practices for early biliteracy development in bilingual and non-bilingual settings and explores the limits of a narrowly tailored structured literacy approach for DLLs.