This study evaluated the effects of a fluency-based reading program with 15 second and third grade students and 15 matched controls. Gains in oral reading fluency on untrained CBM probes were evaluated using a matched-pairs group-comparison design, whereas immediate and two-day retention gains in oral reading fluency on trained passages were evaluated using an adapted changing criterion design. Increases in WRCM due to training and number of trainings to criterion were also evaluated as a function of pre-training fluency levels. Results showed statistically significant gains on dependent measures for the treatment group, mean increases of two to three grade levels in passages mastered, and an optimal pre-training fluency range of 41-60 WRCM. Implications for fluency-based reading programs are discussed.