Adhia A, et al. - Admissions for unilateral TKAs at 151 Illinois non-federal hospitals from January 2016 to June 2018 from the Illinois Hospital and Health Systems Association COMPdata administrative hospital discharge database were chosen in order to describe which people were most at risk for extended length of stay (eLOS) (> 2 days), very eLOS (veLOS) (> 4 days), and non-home discharge (NHD). A total of 72,359 admissions were involved. Females, those 75 years old or more vs those 65-74 years old, non-Hispanic blacks, Hispanics and Asians vs non-Hispanic whites, Medicaid/uninsured patients vs those privately insured, obese individuals, those with non-zero Charlson comorbidity index, and those treated at low volume hospitals were more inclined to have eLOS, veLOS, and/or NHD. In conclusion, to circumvent the above-mentioned patient groups because of bundled payment programs and recent Centers for Medicare and Medicaid Services legislation, arthroplasty surgeons could be incentivized.