In recent years, computer-based testing (CBT) has grown in popularity, is increasingly being implemented across the United States, and will likely become the primary mode for delivering tests in the future. Although CBT offers many advantages over traditional paper-and-pencil testing, assessment experts, researchers, practitioners, and users have expressed concern about the comparability of scores between the two test administration modes. To help provide an answer to this issue, a meta-analysis was conducted to synthesize the administration mode effects of CBTs and paper-and-pencil tests on K—12 student reading assessments. Findings indicate that the administration mode had no statistically significant effect on K—12 student reading achievement scores. Four moderator variables—study design, sample size, computer delivery algorithm, and computer practice—made statistically significant contributions to predicting effect size. Three moderator variables—grade level, type of test, and computer delivery method—did not affect the differences in reading scores between test modes.