Background Medicare currently reimburses hospitals for inpatient admissions with ''bundled'' payments based on patient Diagnosis-related Groups (DRGs) regardless of true hospital costs. At present, DRG 536 (fractures of the hip and pelvis) includes a broad spectrum of patients with orthopaedic trauma, likely with varying inpatient resource utilization. With the growing incidence of fractures in the elderly, inadequate reimbursements from Medicare for certain patients with DRG 536 may lead to growing financial strain on healthcare institutions caring for these patients with higher costs. Questions/purposes The purposes of the study were to determine whether (1) inpatient length of stay; (2) intensive care unit stay; and (3) ventilator time differ among subpopulations with Medicare DRG 536. Methods A total of 56,683 patients, 65 years or older, with fractures of the hip or pelvis were identified in the 2011 and 2012 National Trauma Data Bank. This clinical registry contains data on trauma cases from more than 900 participating trauma centers, allowing analysis of resource One of the authors certifies that he (AMS) or a member of his or her immediate family, has received or may receive payments or benefits, during the study period, an amount of less than USD 10,000 from Orthopaedic Trauma Association (Rosemont, IL). One of the authors certifies that he (JML) or a member of his or her immediate family, has received or may receive payments or benefits, during the study period, an amount of less than USD 10,000 from Bone Therapeutics (Charleroi, Belgium), an amount of less than USD 10,000 from Kuros (Zurich,Switzerland), an amount of less than USD 10,000 from ISTO Technologies (St Louis, MO, USA), an amount of less than USD 10,000 from Emcyte (Fort Myers, FL, USA), an amount of less than USD 10,000 from Royal Marketing Inc (Westmount, Quebec, Canada), an amount of less than USD 10,000 from Graftys (Chicago, IL, USA), an amount of USD 100,000-USD 1,000,000 from Merck (Kenilworth, NJ, USA), and an amount of USD 100,000-USD 1,000,000 from National Institutes of Health (Bethesda, MD, USA). One of the authors certifies that he (JNG) or a member of his or her immediate family, has received or may receive payments or benefits, during the study period, an amount of USD 10,000-USD 100,000 from Bioventus (Durham, NC, USA), an amount of USD 10,000-USD 100,000 from Harvard Clinical Research Institute (Boston, MA, USA), an amount of USD 10,000-USD 100,000 from ISTO Technologies (St Louis, MO, USA), an amount of less than USD 10,000 from Medtronic (Minneapolis, MN, USA), an amount of USD 10,000-USD 100,000 from Stryker (Kalamazoo, MI, USA), an amount of less than USD 10,000 from Affinergy (Durham, NC, USA), an amount of USD 10,000-USD 100,000 from Alphatec (Carlsbad, CA), an amount of less than USD 10,000 from DePuy (Raynham, MA, USA), an amount of less than USD 10,000 from Powered Research (Research Triangle Park, NC, USA), an amount of less than USD 10,000 from KCI (San Antonio, TX, USA), an amount of less than USD 10,000...