This mixed-methods study included qualitative and quantitative methods to answer the questions: (1) What is the relationship between teachers’ level of knowledge (LOK) of the function of the brain as it relates to learning and teacher value of Mind, Brain, and Education science (MBE)? and (2) In what ways do teachers’ value of MBE translate to teaching practices during literacy instruction? Participants included 111 K-12 in-service teachers who have taught between 1to >15 years. There were three phases in this study: (1) A three-part cross-sectional survey was utilized to measure LOK of the function of the brain and teacher value of MBE (n=111); (2) a 4-question interview probed for educators’ beliefs and values of MBE (n=20); and (3) literacy instruction was observed using a checklist-instrument created by the researcher (n=20). Findings from this study identified significant positive correlations between teachers’ level of MBE and value of MBE. Teachers expressed the importance of knowing about brain function when providing, monitoring and modifying instruction for learners via differentiated instruction. As more students with exceptionalities are mainstreamed, the variability of learners in classrooms expands. Understanding students with exceptionalities should encompass teachers’ expansion of knowledge of brain function as it relates to teaching and learning. Therefore, pre-service teacher curriculum and professional development for in-service teachers should include teaching about brain function. Yet, it is not enough to teach educators about how the brain functions, teachers must be provided with opportunities to learn about teaching frameworks that are substantiated in neuroscience.