Research Findings: The goal of the present study was to provide empirical evidence for the importance of mastering reading fluency in early schooling. Study participants were 1,322 students in 3rd grade in 42 schools in a northwestern state. These students were assessed using a battery of reading skill tests as well as comprehensive tests of more general reading outcomes from kindergarten through 3rd grade. Practice or Policy: The results of the study show that mastery of reading fluency prior to currently established benchmarks is a significant positive predictor of later reading skills in primary grades even after student demographic information and initial reading levels are controlled. The results provide additional evidence for the importance of early reading development, early intervention, and preventing reading difficulties as early as possible in schooling.