Curriculum Associates' i-Ready is an adaptive diagnostic and individualized instructional tool that has been used in M-DCPS in the last few years. In addition, in 2016-2017, Curriculum Associates provided the District with results of their predictive model, which used the outcomes of the Fall and Winter i-Ready diagnostic testing to estimate the probabilities of a student scoring at every achievement level on the 2017 FSA ELA and Mathematics for students in grades 3-8. In this Brief, the results of the 2017 FSA are used to investigate the quality of the i-Ready's predictive results.