This article reported the concurrent, predictive, and diagnostic accuracy of a computer-adaptive test (CAT) and curriculum-based measurements (CBM; both computation and concepts/application measures) for universal screening in mathematics among students in first through fourth grade. Correlational analyses indicated moderate to strong relationships over time for each measure, with correlations between CAT and CBM measures across the three assessment periods low to moderate, with the strongest relationships between the CAT and CBM concepts/application measure. Relationships to the state assessment for math for third- and fourth-graders was found to be stronger for the CAT measure than for either the CBM computation or concepts/application measures, with the CAT measure the only significant predictor of the state assessment. Diagnostic accuracy indices found all measures to produce acceptable levels of specificity but limited levels of sensitivity. The study offered one of the first direct comparisons of CAT and CBM measures in screening for mathematics. Implications of using CAT and CBM measures in conducting screening in elementary mathematics were discussed. (Contains 3 tables.)