Curriculum-based assessment for instructional design and curriculum-based measurement both involve measurements of reading fluency, which are often interpreted through comparisons to local norms. However, local norms are not always available and some scholars argue for a criterion-referenced approach when making instructional decisions. The current study examined the relationship between reading fluency and comprehension by having 49 third- and fourth-grade students orally read four passages from standardized reading assessment tools with an incremental increased percentage (0%, 10%, 20%, and 30%) of scrambled words. The number of words read correctly/minute and percentage of comprehension questions correctly answered were recorded. A suggested criterion of approximately 50 words/minute was found using the mean fluency rate of the highest passage in which students demonstrated adequate comprehension, but a wide range of normalcy was also noted. Suggestions for future research are included.