The objectives of this proposal is to describe recent trends in stage II/III rectal cancer post-operative surveillance, determine factors associated with post-operative surveillance compliance and determine if compliance is associated with better survival. This is a retrospective cohort study using SEER-Medicare data. To our knowledge, no research has been done on the proposed objectives using population-based data across the United States. This proposal is also novel because it uses propensity scores to control for potential confounding by indication and delineates between rectal and colon cancer. The results of this study will help optimize the delivery of stage II/III rectal cancer post-operative surveillance in patients over age 65 by providing guidance to patients, clinicians and policy makers about the impact of surveillance on survival outcomes what constitutes best practices.