Treatment of T1D in young children presents many challenges compared to other age groups. In a recent multicenter, randomized controlled trial, we showed significant glycemic improvements when using automated insulin delivery (AID, t:slim X2 insulin pump with Control-IQ technology) compared to standard care (SC) (+12.4% TIR, -0.42% HbA1c) over 13 weeks in N=102 young children (age 2-<6 yrs) with T1D. We focus here on the multiple daily injection (MDI) users at baseline. The cohort included 36 such participants, 10 in SC and 26 using AID. No difference between MDI participants and their pump-using peers was noted for age, gender, ethnicity, or household income; though they showed degraded glycemic control at baseline: TIR 49.7% vs 59.6%, p=0.004; TBR 2.4% vs 3.8%, p=0.016. MDI participants completed 94% of visits virtually and 19/26 were transitioned to AID virtually. Compared with SC, TIR improvement with AID was statistically similar for MDI (+11.6%) and pump (+12.3%) participants (see Figure). Comparable results were seen for other CGM outcomes. With increased TIR of approximately 3h/day, the studied AID system significantly improved glycemic control for prior MDI users, even with a transition almost exclusively performed online. Improvements were not associated with increased risk of hypoglycemia and indistinguishable from the effects observed for prior pump users. Disclosure M.D.Breton: Consultant; Dexcom, Inc., Tandem Diabetes Care, Inc., Roche Diabetes Care, Sanofi, Arecor, Research Support; Dexcom, Inc., Tandem Diabetes Care, Inc., Novo Nordisk. Pedap trial study group: n/a. B.A.Buckingham: Advisory Panel; Medtronic, Novo Nordisk, Consultant; Lilly, Research Support; Medtronic, Insulet Corporation, Tandem Diabetes Care, Inc. M.D.Deboer: Research Support; Dexcom, Inc., Tandem Diabetes Care, Inc. L.Ekhlaspour: Consultant; Ypsomed AG, Tandem Diabetes Care, Inc., Other Relationship; NIH - National Institutes of Health, Research Support; MannKind Corporation, Tandem Diabetes Care, Inc., JDRF, Speaker's Bureau; Insulet Corporation. G.P.Forlenza: Advisory Panel; Medtronic, Consultant; Dexcom, Inc., Insulet Corporation, Tandem Diabetes Care, Inc., Lilly Diabetes, Research Support; Medtronic, Abbott, Dexcom, Inc., Insulet Corporation, Tandem Diabetes Care, Inc. M.Schoelwer: Research Support; Tandem Diabetes Care, Inc., Insulet Corporation. R.Wadwa: Consultant; Eli Lilly and Company, Other Relationship; Dexcom, Inc., Eli Lilly and Company, Research Support; Dexcom, Inc., Eli Lilly and Company, Beta Bionics, Inc., Tandem Diabetes Care, Inc. J.W.Lum: None. R.Beck: Consultant; Eli Lilly and Company, Novo Nordisk, Diasome, Insulet Corporation, Research Support; Tandem Diabetes Care, Inc., Beta Bionics, Inc., Dexcom, Inc., Bigfoot Biomedical, Inc., Medtronic, Ascensia Diabetes Care, Roche Diabetes Care, Eli Lilly and Company, Novo Nordisk. Funding National Institute of Diabetes and Digestive and Kidney Diseases (U01DK127551); Tandem Diabetes Care, Inc.; Dexcom, Inc.