A Study Comparing Dexcom Continuous Glucose Monitoring to Point of Care Glucose Testing for the Management of Hospital and Post-Discharge Subjects With 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