Failure to follow up on test results promptly can lead to delayed diagnoses. This article describes an evaluation of a quality improvement collaborative to improve follow-up on commonly missed test results related to lung and colorectal cancer across 12 VA medical centers. In the study, 11 teams implemented 47 unique interventions, including increased patient engagement through access to test results and preventing EHR notification fatigue. Researchers identified improvements in follow-up rates for abnormal test results at sites with the lowest baseline performance but did not find significant improvements across study sites overall.