Impaired awareness of hypoglycemia (IAH) is attributed to hypoglycemia exposure. Continuous glucose monitoring (CGM) detects more hypoglycemia particularly during sleep. We compared rates and duration of sensor detected hypoglycemia (SDH) and patient reported hypoglycemia (PRH) in people with type 1 diabetes (T1D) using CGM or flash monitoring.We recruited 92 participants with T1D using CGM/Flash reporting >1 hypoglycemic episode in the last month. Participants were defined as normal awareness of hypoglycemia (NAH) (Gold score <4; n=70) and IAH (Gold score >4; n=22) . All wore an additional blinded CGM and recorded episodes of PRH (symptomatic episodes that resolved on carbohydrate ingestion, or a measured glucose <72mg/dl) in real time on a smartphone app for weeks. Sleep status was obtained using an actigraphy monitor. Time in range (59.4 vs. 62.4%; p=0.18) and time < 70 mg/dl (4.6 vs. 6.0%; p=0.44) were not different between groups. Rates and duration of SDH < 70 mg/dl, < 55 mg/dl and < 40 mg/dl during sleep and awake were not different (table 1) . Rates of PRH were also not different (table 1) . While CGM has benefits, it cannot be used to define IAH. CGM allows people with IAH to self-detect hypoglycemia similar to those with NAH, providing a technology supported awareness. Disclosure P.Divilly: None. S.R.Heller: Advisory Panel; Eli Lilly and Company, Medtronic, Mylan N.V., Zealand Pharma A/S, Zucara Therapeutics, Other Relationship; Eli Lilly and Company, Research Support; Dexcom, Inc., Speaker’s Bureau; Novo Nordisk A/S. M.Evans: Advisory Panel; Pila Pharma, Zucara Therapeutics, Other Relationship; Abbott Diabetes, Dexcom, Inc., Medtronic, Novo Nordisk, Research Support; AstraZeneca, Sanofi, Speaker’s Bureau; Lilly Diabetes. J.K.Mader: Advisory Panel; Abbott Diabetes, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Medtronic, Merck Sharp & Dohme Corp., Novo Nordisk A/S, Roche Diabetes Care, Sanofi-Aventis Deutschland GmbH, Speaker’s Bureau; Abbott Diabetes, Eli Lilly and Company, Medtronic, Merck Sharp & Dohme Corp., Novo Nordisk A/S, Roche Diabetes Care, Sanofi-Aventis Deutschland GmbH, Servier Laboratories, Stock/Shareholder; decide Clinical Software GmbH. S.A.Amiel: Advisory Panel; Medtronic, Novo Nordisk, Other Relationship; Sanofi. P.Choudhary: Advisory Panel; Abbott Diabetes, Lilly Diabetes, Medtronic, Research Support; Novo Nordisk, Speaker’s Bureau; Dexcom, Inc., Glooko, Inc., Insulet Corporation, Sanofi. A.Seibold: Employee; Abbott Diabetes, Stock/Shareholder; Abbott. G.Martine-edith: Other Relationship; Novo Nordisk. Z.Mahmoudi: Employee; Novo Nordisk A/S. N.Zaremba: None. U.Soeholm: Research Support; Novo Nordisk A/S. U.Pedersen-bjergaard: Advisory Panel; Novo Nordisk A/S, Sanofi. R.J.Mccrimmon: Advisory Panel; Novo Nordisk, Sanofi, Research Support; Diabetes UK, European Union, MedImmune. B.E.De galan: Research Support; Novo Nordisk. E.Renard: Consultant; Abbott, AstraZeneca, Boehringer Ingelheim International GmbH, Dexcom, Inc., Insulet Corporation, LifeScan, Lilly, Novo Nordisk, Roche Diabetes Care, Sanofi, Tandem Diabetes Care, Inc. Funding Innovative Medicines Initiative (777460)