Introduction: In the USA, endovascular capable stroke centers (ECC) that perform mechanical thrombectomy (MT) for large vessel stroke can be accredited by a number of agencies. However, there remains little evidence on recommendations for minimum case volume required for centers to maintain competency. Hypothesis: Clinical outcomes (namely hospital mortality and home discharge disposition) of stroke patients treated by MT are associated with center volume but not accreditation status. Methods: We obtained nationwide MedPAR data from the Center for Medicare and Medicaid Services (CMS) for 2017 and 2018. Endovascular MT cases were identified using ICD 10 codes. A list of ECCs was obtained from the Joint Commission, HFAP, DNV, and State Health Departments and was cross-referenced with a list of accredited centers. Independent t-tests were used to compare the mean rates of mortality and home discharge between accredited and non-accredited centers. Pearson’s correlation was used to test the association of annual case volume (in 10 groups in logarithmic increments from minimum to maximum) with the rates of mortality and home discharge. Results: In 2017 and 2018, we identified 29,536 cases of MT that were performed at 847 centers (of which 354 were accredited) across the USA. There was no significant difference between accredited and non-accredited centers with regard to hospital mortality (14.8% vs. 14.5%, p-value=0.34) and home discharge disposition (12.1% vs. 12.0%, p-value=0.78). Hospital mortality was significantly negatively correlated with center volume (r=-0.83, 95%CI=-0.96 to -0.44, p-value=0.003), whereas home discharge disposition was significantly positively correlated with center volume (r=0.68, 95%CI=0.09 to 0.92, p-value=0.030). Conclusions: Accreditation showed no correlation to clinical outcomes. However, increasing volume of MT cases in ECCs correlated to increasing mortality and decreasing rate of home discharge.