Patient description: The patient is a 24-year-old man who has had type 1 diabetes for 11 years. He presents to the emergency room with hyperglycemia and concern for possible diabetic ketoacidosis after not taking his insulin for 3 days. The patient reports that he is currently homeless and has lost his supply of insulin, syringes, glucometer, and glucose testing supplies. The patient states that at the time of his initial diagnosis with type 1 diabetes he was hospitalized with a glucose value >1000 mg/dL. At the time, he was experiencing polyuria, polydipsia, and polyphagia. He reports that he has been on insulin since the time of his diagnosis, and he has never been prescribed oral agents for diabetes management. Most recently, he has been using insulin glargine 55 units once daily, and insulin aspart sliding scale 3 times daily. The patient has had previous episodes of diabetic ketoacidosis, for which he was hospitalized. With this episode of hyperglycemia, he is not experiencing any nausea, vomiting, or abdominal discomfort, and he appears well. His lab studies showed: A1c: 11.3% Creatinine: 0.9 mg/dL with eGFR >60 mL/min Aspartate aminotransferase (AST): 17 U/L Alanine aminotransferase (ALT): 14 U/L Beta-hydroxybutyrate: 0.1 mmol/L Bicarbonate: 25 mEq/L Anion

Clinical trial eligibility criteria: eligible ages (years): 7.0-999.0,  Type 1 Diabetes Type 2 Diabetes for A subject is eligible for the user evaluation study if all of the following are met: 1. Subject is 7 years or older at time of screening 2. Subject is current insulin pump user for at least 3 months 3. Subject has the following CGM experience as determined by the Investigator Has experience and is able to insert/change sensor by herself/himself and Has experience and can recharge the transmitter and Has experience and can read sensor data in real-time on her/his pump screen 4. Subject/legal representative has signed a Patient Informed Consent and is willing to comply with the study procedures; 5. Subject is willing to complete study questionnaires throughout the study 6. Must have the following clinical diagnosis: 1. Type 1 diabetes, for a minimum of 6 months prior to enrollment for A subject is excluded from the user evaluation if any of the following are met: 1. Female subject has a positive urine pregnancy screening test. 2. Female subject who plans to become pregnant during the course of study. If a woman becomes pregnant during participation, she will be withdrawn 3. Subject has any condition that, in the opinion of the Investigator or qualified Investigational Centre staff, may preclude him/her from participating in the study and completing study related procedures. 4. Subject has impaired vision or hearing problems that could compromise the handling of the device as determined by Investigator or qualified Investigational Centre staff 5. Subject is unable to tolerate tape adhesive in the area of sensor placement 6. Subject has any unresolved adverse skin condition in the area of sensor placement (e.g. psoriasis, rash, Staphylococcus infection) 7. Subject has travel plans which would make it difficult for the subject to attend on-site study visits as scheduled 8. Subject is actively participating in an investigational study (drug or device) wherein he/she has received treatment from an investigational study drug or investigational study device in the last 2 weeks (CEP267 User Evaluation is not included in this