This study investigated the relation between the easyCBM Benchmark Assessments in both mathematics and reading and the Smarter Balanced assessment, widely adopted across the United States. Data for the study were obtained from a convenience sample of approximately 1,000 students per grade in grades 3-8 provided by two school districts in the Pacific Northwest. Results indicate that the easyCBM CCSS math assessments are a strong predictor of the Smarter Balanced total math score, with correlations ranging from 0.69 to 0.84 across grades and seasonal benchmarks. Linear regression analyses indicate that the different easyCBM CCSS math measures account for 68% to 77% of the variance in Smarter Balanced total math score. In addition, all of the easyCBM reading assessments are significantly related to the Smarter Balanced English language arts total score, with correlations ranging from 0.50 to 0.69 across grades, measure types, and seasonal benchmarks. Linear regression analyses indicate that the different easyCBM reading measures account for 50% to 62% of the variance in Smarter Balanced English language arts score.