Abstract: Research is failing to consistently report theoretical frameworks, increasing the gap between research and practice, and increasing the difficulty teachers face in effectively matching interventions with student needs. However, this lack of theoretical understanding has not been well documented in the current literature. The purpose of this systematic review is to determine the literacy theories used in published articles within the Journal of Adolescent and Adult Literacy (JAAL). JAAL is a peer-reviewed literacy journal that focuses on providing research-based practices for teachers. The present study includes an overview of published theories of reading and writing and the results of coding for these theories within a sample of ninety-four published intervention articles. Through this review, we have uncovered several areas for future research: (1) clarification of the differences between sociocultural and sociocognitive theories, (2) an increased emphasis on the mutual impact of reading and writing, and (3) a need to diversify theories used for reading and writing instruction. on building resilience with struggling readers and writers, while Feng and Kuo focus on secondlanguage learners. All four researchers have an interest in teacher educators. The current project on reading and writing theories blossomed out of their combined interest to prepare highly qualified literacy teachers. They noted that teacher candidates and in-service teachers did not have opportunities to learn theories in their preparation programs, and many journal articles for practitioners did not emphasize theories. To document the specific limitations presented in research, the teach convened and conducted a systematic literature review of what literacy theories were presented with instructional practices. Their work notes that significant gaps in the theories presented do exist, and that many researchers do not explicitly describe the theories that underpin their research endeavors. PUBLIC INTEREST STATEMENT Researchers and teachers know that literacy includes both reading and writing; however, research consistently focuses on reading while leaving writing behind. Moreover, teachers are aware that they should be providing clear instruction based on best research-based practices and theoretical understandings. Yet, teachers are not often given specific training on what theories apply to reading, writing, and generalized literacy. In this study, we reviewed research articles written for practitioners to determine how reading and writing theories are applied to best practices. We summarize theories and provide recommendations for including theoretical perspectives in future research. Teachers and literacy professionals benefit from our work by better understanding theories supporting reading and writing in classrooms.