Lexia® Core5® Reading performance measures were shown to be valid indicators of reading ability based on comparisons with scores on the Dynamic Indicators of Early Literacy Skills (DIBELS) Next version. Strong correlations between Core5 performance measures and DIBELS Next scores were significant at the beginning, middle, and end of the school year. Additionally, when students are On Target or reach benchmark, their performance in Core5 is associated with proficiency on DIBELS Next at the end of the year. These findings indicate that Core5 can serve – not only as an instructional program – but as a key component in a school's literacy assessment.