This quasi-experimental study examined differences in student reading outcomes. Participants were third grade non-struggling readers. Intervention classrooms included core curriculum instruction plus evidence-based reading comprehension instruction and differentiated repeated readings. Comparison classrooms provided core curriculum instruction only. Significant group mean differences were found on four fluency-related measures, but not for three other measures. Non-significant mean score differences had moderate effect sizes in the direction of improved reading outcomes for the intervention group, including a statewide high stakes test (Hedges g = 0.41). Results suggest that the addition of evidence-based differentiated reading instruction is beneficial for Tier I.