© 2015 American College of Surgeons. Background: Under bundled payment initiatives, providers will be held financially responsible for patients' acute and post-acute care costs. Certain patients, termed high utilizers, use disproportionate shares of resources during 1 year. The aim of this study was to identify high utilizers, describe their costs, and determine whether preoperative characteristics predict high utilizer status. Study Design: Colectomy patients with 1-year follow-up were identified in a linked clinical (American College of Surgeons NSQIP) and administrative (Medicare inpatient claims) dataset (2005 to 2008). Cost of inpatient care was calculated by multiplying patient Medicare charges in each cost center by cost-to-charge ratios from the Medicare cost reports. A mixed-effects logistic model quantified the association between preoperative characteristics and being a high utilizer after elective and emergent colectomies. Results: One thousand and fifty-five of 10,561 colectomy patients accounted for >50% of the inpatient care cost of the entire cohort during 1 year postoperatively. This top decile of patients were labeled high utilizers and had substantially greater costs in the following cost centers: intensive care ($36,322 vs $0), respiratory ($2,875 vs $22), radiology ($649 vs $29), and cardiology ($5,057 vs $166) (all p < 0.001). High utilizers more frequently had emergent index colectomies (43% vs 17%; p < 0.001). Patients with American Society of Anesthesiologists class IV and V had 2-fold increased odds of being high utilizers after both elective (odds ratio= 2.72; 95% CI, 1.89-3.90) and emergent colectomies (odds ratio= 2.09; 95% CI, 1.23-3.55). Conclusions: Patients in the top cost decile account for the majority of costs in the year after colectomy, disproportionately accumulate those costs in particular cost centers, and can be identified preoperatively.