Becoming a fluent reader has been established as important to reading comprehension. Prosody (expression) is an indicator of fluent reading that is linked to improved comprehension in students across elementary, middle, and secondary grades. Fluent reading is most often evaluated by classroom teachers through the use of a rubric, with the most common being the Multi-Dimensional Fluency Scale (MDFS) and the National Assessment of Educational Progress (NAEP) scale. This investigation uses a generalizability study (G-study) and a decision study (G-study) to determine reliability and efficiency of the two rubrics across five raters and two rating occasions in 177 first- through third-grade students. The results revealed the MDFS and NAEP to be parallel instruments with variance attributable to raters ranging from nearly 0 to 2.2%. Generalizability coefficients ranging from 0.91 to 0.94, indicating high reliability were found for both instruments. Recommendations for administration efficiency of each rubric are provided and instructional implications are discussed.