202 Background: T-stage alone is currently used to guide treatment for incidentally discovered gallbladder cancer. We aimed to develop a more robust predictive model for discovering distant or locoregional residual disease at the time of re-resection. Methods: All patients with incidentally discovered gallbladder cancer who underwent re-resection at 10 institutions from 2000-2015 were included. We utilized routine pathology data from initial cholecystectomy to create a gallbladder cancer predictive risk score (GBRS) for finding distant or locoregional residual disease at re-resection and predicting overall survival (OS). Results: Of 449pts with gallbladder cancer, 262 (58%) were incidentally discovered and underwent attempted re-resection. Advanced T-stage, grade, and lymphovascular (LVI) and perineural (PNI) invasion were all associated with increased rates of distant and locoregional residual disease, and decreased OS. Each pathologic characteristic was assigned a value (T1a: 0, T1b: 1, T2: 2, T3/4: 3; ...