Patient-reported outcomes are a useful tool to understand the impact of treatments in clinical application on a large scale. This retrospective study characterized patient-reported outcomes of a large cohort of adults in the United States with type 2 diabetes using a tubeless insulin pump (Omnipod® or Omnipod DASH™ Insulin Management System, Acton, MA). From Jan. 2015-Jan. 2020, patient-reported outcomes were recorded before and ≥90 days after initiating system use. Primary outcomes were change in self-reported A1C and total daily dose of insulin. Patients (N=2,335) were aged (mean±SD) 58±11y and 53% female. The percentage of users with a self-reported A1C ≤8% increased from 33% pre-tubeless pump to 64% post-tubeless pump, and the percentage with a self-reported A1C >9% decreased from 44% to 15% (p<0.001, Table). Self-reported A1C decreased from 9.2±2.7% to 7.9±2.2% (p<0.001). The self-reported total daily insulin for those with data available (n=2,130) was 33±49 U/d lower on average from pre-tubeless pump to post-tubeless pump, from 104±68 U/d to 71±40 U/d (p<0.001). These patient-reported outcomes provide positive evidence that use of a tubeless insulin pump was associated with glycemic outcomes that exceed U.S. National Healthcare Effectiveness Data and Information Set (HEDIS) standards for adequate diabetes management. Disclosure A.L. Carlson: Consultant; Self; Medtronic. Research Support; Self; Abbott, Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, Medtronic, Novo Nordisk A/S, Sanofi, UnitedHealth Group. L.M. Huyett: Employee; Self; Insulet Corporation. J. Jantz: Employee; Self; Insulet Corporation. A. Chang: Employee; Self; Insulet Corporation. Stock/Shareholder; Self; Insulet Corporation. T. Vienneau: Employee; Self; Insulet Corporation. Stock/Shareholder; Self; Insulet Corporation. T.T. Ly: Employee; Self; Insulet Corporation. Funding Insulet Corporation