Safety of Artificial Pancreas Therapy in Preschoolers, Age 2-6

Inclusion Criteria

• Age ≥ 2 and < 6 years old at the time of consent
• Clinical diagnosis, based on investigator assessment, of type 1 diabetes for at least 3 months and using insulin at the time of enrollment
• Use of an insulin pump in the past 3 months
• Use of Dexcom G6 for at least 11 out of the last 14 days
• Parent/guardian(s) have familiarity with and use of carbohydrate ratios for meal boluses
• Living with one or more parent/guardian knowledgeable about emergency procedures for severe hypoglycemia and able to contact emergency services and study staff
• At least one parent/guardian is willing to stay with the child during the hotel/house portion of the study on the dates selected by the study team
• Investigator has confidence that the parent/guardian(s) can successfully operate all study devices and is capable of adhering to the protocol
• Willingness to switch to lispro (Humalog) or aspart (Novolog) if not already, and to use no other insulin besides lispro (Humalog) or aspart (Novolog) during the study
• Total daily insulin dose (TDD) of at least 5 U/day
• Willingness not to start any new non-insulin glucose-lowering agent during the course of the trial
• Child participant and parent/guardian(s) willingness to participate in all training sessions as directed by study staff
• Willingness to discontinue non-Tandem t: slim insulin pumps during the entire study
• Willingness to wear a Dexcom G6 sensor during the entire study
• An understanding and willingness to follow the protocol and sign informed consent

Exclusion Criteria

• Hypoglycemia induced seizure or loss of consciousness in the past 3 months
• Diabetes Ketoacidosis in the past 3 months
• Use of diluted insulin
• Concurrent use of any non-insulin glucose-lowering agent
• Hemophilia or any other bleeding disorder
• A condition, which in the opinion of the investigator or designee, would put the participant or study at risk. These conditions may include:
• Acute illness at the time of the enrollment visit (fever of 101 or higher, vomiting, diarrhea)
• Addison's disease
• Diagnosed at less than 1 year of age without positive antibodies
• Decreased renal function
• Cystic fibrosis
• Other chronic conditions, such as an underlying seizure disorder
• Participation in another pharmaceutical or device trial at the time of enrollment or during the study.
• Having a family member(s) employed by Tandem Diabetes Care, Inc. 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.