This project appears to be the first to determine growth rates for writing using Curriculum-Based Measurement-Written Expression (CBM-WE). Growth rates, or the amount of change over time, help educators track how much progress can be expected given typical instruction. CBM-WE probes were administered to a sample of 1,004 students in first through fifth grades within a school district. The writing probes were scored using production-dependent variables: Total Words Written (TWW), Words Spelled Correctly (WSC), and Correct Word Sequence (CWS). Data were analyzed by grade level and gender. Results are presented as weekly growth rates. Growth rates were calculated from fall to winter, winter to spring, and from fall to spring. This study found higher growth rates in the lower grades and the lowest growth rates in fifth grade. Negative growth was found when examining winter to spring scores for students in third through fifth grades. Girls typically showed more improvement than boys. Results will be beneficial for educators to understand and monitor elementary student progress in written expression.