Background and Purpose— Multiple randomized clinical trials have demonstrated the superiority of endovascular therapy (ET) for large vessel occlusion acute ischemic stroke (AIS). Few centers can provide ET, and significant debate exists about the most efficient and effective ways to provide ET. We sought to assess real-world utilization of ET, the extent to which patients are transferred from one hospital to another for therapy and the implications of transfer status on outcomes. Methods— We used the 2015 to 2016 Healthcare Cost and Utilization Project Nationwide Readmissions Database, which contains nationwide data on nearly half of US admissions. We identified index AIS admissions, vascular risk factors, and treatment with intravenous thrombolysis and ET using International Classification of Disease, Ninth Revision , and International Classification of Disease, Tenth Revision Clinical Modification codes. Main predictors of outcome were treatment with ET and whether there was an interhospital transfer during the index AIS hospitalization. Among patients with AIS readmitted within 30 days, we examined 3 main outcomes: total charges, length of stay, and in-hospital mortality. Results— A total of 23 121 AIS admissions were treated with ET and 874 229 without. Over 5% of patients who received ET were transferred during the index admission compared with <2% of those not treated with ET. Length of stay and total charges were significantly higher in patients transferred (12.3 versus 9.6 days and $233 626 versus $182 881, respectively). More patients treated with ET who were not transferred to the index hospital were discharged home (25.3% versus 44.4%), and ≈25% of patients transferred for ET died during the hospitalization compared with 15.5% not transferred. Conclusions— The minority of all patients with AIS receive ET. The majority of patients who receive ET present directly to the center that performs the procedure, and those transferred for ET have higher length of stay, cost, and mortality that those not transferred.