The goal of this project was to provide empiric evidence about the benefit to US veterans and the VA of capturing data from a citywide clinical informatics network (INPC) to assess care received outside the VA. We identified 468 veterans diagnosed with colorectal cancer from 2000–2007 in the Indianapolis VA cancer registry. Electronic VA healthcare data were linked with electronic health records from the regional health information organization (RHIO) INPC; 341 matches were found. Both the VA and INPC systems were queried regarding receipt of surveillance tests. The proportion with additional data from INPC varied by test: colonoscopy (3%), CT scan/abdomen (13%), CT scan/chest (79%), carcinoembryonic antigen test (8%), and other laboratory tests (25%–53%). An incremental benefit of linking VA and INPC data was present and may increase when expanded beyond patients with a single condition. New, important information about care outside the VA is obtained through RHIO data linkage.