['To understand the influence of age and comorbidities, this study analyzed the incidence and risk factors for post-hepatectomy morbidity/mortality in patients with "borderline" (BL) operability, defined by the preoperative factors: age ≥75 years, dependent function, lung disease, ascites/varices, myocardial infarction, stroke, steroids, weight loss >10%, and/or sepsis.', 'All elective hepatectomies were identified in the 2005-2013 ACS-NSQIP database. Predictors of 30-day morbidity/mortality in BL patients were analyzed.', 'A 3,574/15,920 (22.4%) patients met BL criteria. Despite non-BL and BL patients undergoing similar magnitude hepatectomies (P\u2009>\u20090.4), BL patients had higher severe complication (SC, 23.3% vs. 15.3%) and mortality rates (3.7% vs. 1.2%, P\u2009<\u20090.001). BL patients with any SC experienced a 14.1% mortality rate (vs. 7.3%, non-BL, P\u2009<\u20090.001). Independent risk factors for SC in BL patients included American Society of Anesthesiologists (ASA) score >3 (odds ratio, OR\u2009-\u20091.29), smoking (OR\u2009-\u20091.41), albumin <3.5\u2009g/dl (OR\u2009-\u20091.36), bilirubin >1 (OR\u2009-\u20092.21), operative time >240\u2009min (OR\u2009-\u20091.58), additional colorectal procedure (OR\u2009-\u20091.78), and concurrent procedure (OR\u2009-\u20091.73, all P\u2009<\u20090.05). Independent predictors of mortality included disseminated cancer (OR\u2009-\u20090.44), albumin <3.5\u2009g/dl (OR\u2009-\u20091.94), thrombocytopenia (OR\u2009-\u20091.95), and extended/right hepatectomy (OR\u2009-\u20092.81, all P\u2009<\u20090.01).'] Is borderline operability in hepatectomy patients associated with higher rates of failure to rescue after severe complications?