Universal screening in reading is a common, and often required, practice in early elementary school. Computer-adaptive screening tools, such as "Istation's Indicators of Progress-Early Reading" (ISIP-ER), are often chosen for this purpose in schools. In our present study, we examine the validity evidence between the ISIP-ER in kindergarten and third grade "State of Texas Assessments of Academic Readiness" (STAAR) reading scores, the classification accuracy of ISIP-ER to predict which students will meet STAAR reading expectations, and a cut score to maximize classification accuracy for the local context. The sample included 962 students (M[subscript age] = 6.19 years; SD[subscript age] = 0.37) from 15 elementary schools in one suburban school district in Texas. As for validity, the correlation between ISIP-ER in kindergarten and the third grade STAAR was moderate (r = 0.48). Classification accuracy analyses using the vendor-recommended cut score found sensitivity (0.63) and specificity (0.70) were all below recommended levels. Using a locally determined cut score, sensitivity (0.92) was improved, but specificity (0.33) was substantially decreased. The findings suggest ISIP-ER has some limitations in the accurate identification of students at risk for poor outcomes on a state-mandated reading test and will likely need to be combined with other assessments or progress monitoring data.