Background: Carb-counting is a significant burden for persons with diabetes who require insulin to mitigate postprandial hyperglycemia. A closed-loop (CL) system with auto meal-bolus that eliminates manual mealtime bolusing was studied in adults with T1D. Methods: The system included the MiniMed™ 780G pump and a smartphone-paired smartwatch with the KLUE application that detects eating hand-gestures using motion sensors. A smartphone algorithm converted eating hand-gestures to carb amounts that were relayed to the pump for automatic bolusing. For 6 days, participants (N=17, aged 18-75 years) with T1D used the system with the KLUE app disabled and completed traditional carb-counting and -entry (Baseline) . Thereafter, the KLUE app was enabled for 5 days and carb-counting/carb-entry was prohibited (Study) . Participants were given the same 5 test-meals (one/day) of varying caloric and carb sizes during both periods. Otherwise, they had no other meal restrictions. Results: No significant difference in TIR was observed between periods and time spent at <70 mg/dL was significantly less during the Study period (Table) . Conclusion: Data suggest that the novel CL system maintains glycemic control similar to that with manual meal bolusing. By eliminating the burden of carb-counting, the new CL system may improve the quality of life in persons with T1D. Disclosure A.Roy: Employee; Medtronic. A.Tirosh: Advisory Panel; Abbott Diagnostics, AstraZeneca, Boehringer Ingelheim International GmbH, Merck & Co., Inc., Novo Nordisk, Sanofi, Consultant; Bayer AG, DreaMed Diabetes, Ltd., Research Support; Medtronic, Speaker's Bureau; Eli Lilly and Company. B.Grosman: Employee; Medtronic. D.Miller: Employee; Medtronic. T.Engel: None. O.Cohen: Employee; Medtronic. R.Shalit: Speaker's Bureau; AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Medtronic, Novo Nordisk. S.Shalem: None. M.Laron hirsh: None. Y.Cohen: None.