We need new approaches for reducing the academic failure rate of children with learning disabilities that causes many to drop out of school. The long-term effects of dropping out of school include poor employment opportunities linked to poor health outcomes (Egerter et al., 2009) and lower life expectancy (Begier, Li, & Meduro, 2013). We propose that new instructional approaches based on a child's working memory profile can improve learning. Working memory encompasses an individual's ability to process and store incoming information over short periods. It is a powerful predictor of learning (Alloway, 2009; Maehler & Schuchardt, 2016). We think that by knowing a child's working memory profile, interventions and instructional approaches can be tailored to take advantage of working memory strengths and weaknesses. This approach aligns with new initiatives promoting precision medicine whereby basic science, diagnostic testing, and evidence-based knowledge are used to individualize treatment (Porche, 2015). The success of this precision approach rests on (a) our ability to comprehensively assess working memory in children, (b) a clear understanding of how working memory develops over time in children with and without learning disabilities, and (c) how working memory and other cognitive abilities, such and oral language and intelligence, interact over the course of development. These goals and the steps to achieve them are the focus of our project. In our initial R01 we developed and tested a new, comprehensive, computer-administered working memory battery for children with second graders from three states. In this renewal project we will utilize an accelerated longitudinal design to follow children with typical development (TD), dyslexia, and comorbid dyslexia and developmental language disorder (DLD) from kindergarten through 6th grade. Our project will shift current research and clinical practice paradigms by providing (a) new, empirically tested longitudinal models of working memory in children; (b) new information about the initial status and growth trajectory of working memory from kindergarten through 6th grade; (c) new information about the longitudinal relations among working memory, cognitive abilities, and academic performance over time, and (d) norms for the Comprehensive Assessment Battery for Children – Working Memory so that results can be used by researchers, educators, and clinicians to tailor interventions and instruction. This will be the first comprehensive, longitudinal study of working memory in children in the U.S.