A Pilot Test of t:Slim X2 With Control-IQ Technology

Inclusion Criteria: To be eligible for the study, a subject must meet the following criteria: 1. Clinical diagnosis, based on investigator assessment, of type 1 diabetes for at least one year and using insulin for at least 1 year 2. Use of an insulin pump for at least 6 months with established parameters for basal rate(s), carbohydrate ratio(s) and insulin sensitivity factor(s) for at least 3 months. 3. Age 18.0 to \<75.0 years 4. Hemoglobin A1c \<10.5% 5. For females, not currently known to be pregnant If female and sexually active, must agree to use a form of contraception to prevent pregnancy while a subject in the study. A negative serum or urine pregnancy test will be required for all premenopausal women who are not surgically sterile. Subjects who become pregnant will be discontinued from the study. Also, subjects who during the study develop and express the intention to become pregnant within the timespan of the study will be discontinued. 6. Willingness to suspend use of any personal CGM for the duration of the clinical trial once the study CGM is in use 7. Investigator has confidence that the subject can successfully operate all study devices and is capable of adhering to the protocol 8. Currently using no insulins other than one of the following rapid-acting insulins at the time of enrollment: insulin lispro (Humalog), insulin aspart (Novolog), or insulin glulisine (Apidra). Willingness to switch to lispro (Humalog) or aspart (Novolog) if using glulisine (Apidra). 9. Total daily insulin dose (TDD) at least 10 U/day and ≤100 U/day 10. Weight at least 25 kg and not greater than 140 kg Exclusion Criteria: 1. More than one episode of diabetic ketoacidosis (DKA) in the 6 months prior to enrollment 2. More than one episode of severe hypoglycemia involving seizure or loss of consciousness in the 6 months prior to enrollment 3. Concurrent use of any non-insulin glucose-lowering agent (including GLP-1 agonists, Symlin, DPP-4 inhibitors, SGLT-2 inhibitors, biguanides, sulfonylureas and naturaceuticals). 4. Hemophilia or any other bleeding disorder 5. A condition, which in the opinion of the investigator or designee, would put the subject or study at risk 6. Participation in another pharmaceutical or device trial at the time of enrollment or during the study 7. Employed by, or having immediate family members employed by Tandem Diabetes Care, Inc. or TypeZero Technologies, LLC, or having a direct supervisor at place of employment who is also directly involved in conducting the clinical trial (as a study investigator, coordinator, etc.); or having a first-degree relative who is directly involved in conducting the clinical trial