Inpatient Use of Personal Continuous Glucose Monitor (CGM) to Improve Diabetes Mellitus Control

Inclusion Criteria: 1. Patients with ages above 18 years old at the time of informed consent. 2. Male or female 3. Admitted to non-ICU setting in brick-and-mortar medical and surgical ward or admitted to Advanced Care at Home Program. 4. Admitted under observation or inpatient status. 5. Expected to remain in the hospital for more than 48 hours. 6. Patients that are using a transcutaneous or implantable real time CGM as outpatient and are bringing it to the hospital. 7. Patients with diagnosis of diabetes mellitus or hyperglycemia requiring treatment with SQ insulin in the hospital either with multiple daily injections or subcutaneous infusion of insulin via insulin pump. Exclusion Criteria: 1. Participants unable to provide informed medical consent. 2. Participants admitted to Intensive Care Units (ICU). Enrollment is possible after transferring out of the ICU. 3. Actively being treated for DKA (diabetes ketoacidosis) or HHS (hyperosmolar hyperglycemic state) 4. Patients with a diagnosis of liver cirrhosis. 5. Patients with a diagnosis of ESRD or Acute Renal Failure on hemodialysis or peritoneal dialysis. 6. Patients with planned MRI or surgical procedure. Enrollment is possible after MRI or surgery. 7. Participants with allergy to medical grade adhesive or medical tape. 8. Participants who are pregnant, wanting to become pregnant, or nursing during study period. 9. Participants using Medtronic and Dexcom sensors and taking acetaminophen more than 4g per day or more than 1gm every 6 hours. 10. Participants using Dexcom sensors and taking hydroxyurea. 11. Participants using Libre sensors and taking over 500 mg of ascorbic acid. 12. Patients using Eversense sensors and taking tetracycline type of antibiotics. 13. Participants actively enrolled in other studies addressing their CGM use unless express permission is obtained from prior study research team principal investigator or co-principal investigator.