We examined the criterion validity and diagnostic efficiency of oral reading fluency (ORF), word reading accuracy, and reading comprehension (RC) for students in Grades 7 and 8 taking into account form effects of ORF, time of assessment, and individual differences, including student designations of limited English proficiency and special education status. Participants were 1,481 students in Grade 7 and 1,462 in Grade 8 attending four middle schools in the Pacific Northwest. Results indicated that (a) the majority of variance in ORF is between individuals, (b) a single ORF passage appears to be equally predictive of the state assessment of reading performance as the mean or the median across three passages, (c) ORF and RC explain 55-58% of the variance in the state assessment, and (d) a combination of ORF and RC leads to more accurate diagnosis of students who might be at risk for not passing the state assessment than either measure alone. Word reading accuracy contributes little to the prediction of state test scores or risk status. Implications for practice and future research are addressed.