Drawing inferences about the extent to which student performance reflects instructional opportunities relies on the premise that the measure of student performance is reflective of instructional opportunities. An instructional sensitivity framework suggests that some assessments are more sensitive to detecting differences in instructional opportunities compared to other assessments. This study applies an instructional sensitivity framework to compare student performance on two different mathematics achievement measures across five states and three grade levels. Results suggest a range of variation in student performance among teachers on the same mathematics achievement measure, variation between the two different mathematics achievement measures, and variation between grade levels within the same state. Findings highlight initial considerations for educators interested in selecting and evaluating measures of student performance that are reflective of instructional opportunities.