Length of stay (LOS) after carotid endarterectomy (CEA) and carotid artery stenting (CAS) for asymptomatic disease is used as a quality measure by payers and affects hospital operating margins. Patient-level Medicaid status has been shown to be associated with longer LOS. Our goal was to assess the association between hospital-level Medicaid prevalence and postoperative LOS after CEA and CAS. The National Inpatient Sample was queried from 2006 to 2014 for CEA and CAS performed for asymptomatic carotid stenosis. Hospital-level Medicaid prevalence was divided into quartiles. The quartiles were further categorized into low Medicaid prevalence (LM; lowest quartile), medium Medicaid prevalence (MM; second and third quartiles), and high Medicaid prevalence (HM; fourth quartile) cohorts. The primary outcome evaluated was postoperative LOS >1 day. Secondary outcomes included perioperative complications. There were 984,283 patients with asymptomatic carotid stenosis who underwent CEA (88%) or CAS (12%). Among patients who underwent CEA, 1.9%, 34.7%, and 63.4% received care at hospitals with LM, MM, and HM prevalence, respectively. Among patients who underwent CAS, 1.9%, 26.4%, and 71.8% received care at hospitals with LM, MM, and HM prevalence, respectively. Hospital-level Medicaid prevalence cohorts for CEA differed by age, sex, race, insurance, hospital size, region, neighborhood income, diabetes, and anemia (P < .05). Cohorts for CAS differed by age, race, insurance, hospital size, region, neighborhood income, illegal drug use, diabetes, and chronic renal disease (P < .05). Neurologic (0.8% vs 0.9% vs 0.9%; P = .83) and cardiac complications (0.9% vs 1.2% vs 1.2%; P = .24) after CEA were similar between hospitals with LM, MM, and HM prevalence, respectively. Neurologic (1.1% vs 1% vs 1.2%; P = .42) and cardiac complications (2% vs 1.3% vs 1.5%; P = .46) after CAS were also similar. Mean postoperative LOS after CEA at hospitals with LM, MM, and HM prevalence was 1.4 ± 1.5 days, 2.1 ± 2.5 days, and 2.2 ± 2.8 days (P = .0001), respectively. Mean postoperative LOS after CAS at hospitals with LM, MM, and HM prevalence was 1.7 ± 2.6 days, 1.8 ± 2.1 days, and 2 ± 2.6 days (P < .0001), respectively. On multivariable analysis for CEA, relative to LM prevalence, MM prevalence (odds ratio [OR], 1.62; 95% confidence interval [CI], 1.17-2.24) and HM prevalence (OR, 1.66; 95% CI, 1.2-2.28; P = .009) were associated with LOS >1 day. On multivariable analysis for CAS, HM prevalence was associated with LOS >1 day (OR, 1.42; 95% CI, 1.06-1.91; P = .003). Increased hospital-level Medicaid prevalence is associated with longer LOS after CEA and CAS for asymptomatic carotid stenosis. Medicaid prevalence is important in creating appropriate risk-adjusted quality metrics and developing care pathways that optimize hospital reimbursement.