Dexcom CGM vs Blood Glucose Testing for Type 1 Diabetes

Inclusion Criteria: * Known history of T1D treated with insulin therapy (human regular or rapid-acting analogs or ultra-rapid analogs \[lispro, aspart, glulisine, fast-acting insulin aspart, insulin lispro\]), intermediate-acting (NPH and premixed formulations) or long-acting basal (glargine, detemir, degludec) formulations. * Admission diagnosis of T1D with poorly controlled diabetes (blood glucose \> 180 mg/dl, HbA1c \> 7%), including diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar state (HHS). * Expected length of hospital stay \> three days at the time of randomization Exclusion Criteria: * Patients admitted to the ICU * Subjects using CGM technology before admission * Subjects with type 2 diabetes * Treatment with systemic immunosuppressive agents * Cystic fibrosis * Prisoners * Patients expected to require MRI procedures during hospitalization. * Female subjects who are pregnant or breastfeeding at enrollment into the study. * Subjects not willing to wear a CGM device * Subjects with clinically relevant hepatic disease (diagnosed liver cirrhosis and portal hypertension) and end-stage kidney disease (eGFR\< 30 ml/min), or terminal illness. * Subjects with a history of cognitive impairment, dementia, or mental condition rendering the subject unable to understand the nature and consequences of the study