We report the results of a test-retest and alternate form reliability study of grade 1, 3, 5, and 8 reading measures from the easyCBM assessment system. Approximately 50 students in each grade participated in the study. In Grade 1, we studied the following measures: Phoneme Segmenting, Letter Sounds, Letter Names, Word Reading Fluency, and Passage Reading Fluency. In Grade 3, we studied Word and Passage Reading Fluency and Multiple Choice Reading Comprehension. In both Grades 5 and 8, we studied Passage Reading Fluency and Multiple Choice Reading Comprehension. Correlations for the test-retest analyses ranged from 0.45 to 0.97. Correlations for the alternate form analyses ranged from 0.76 to 0.97. (Contains 20 tables.)