PS230005 Control-IQ 1.5 Post-Approval Study

Eligibility Criteria

• * Self-reported type 1 diabetes who have been prescribed the Control-IQ 1.5 system in the t:slim X2 or Mobi insulin pump
• * Age 2 to \<6 years at time of screening
• * Using an insulin approved for use in the pump
• * Using an iCGM sensor approved for use with the pump
• * Agreement to use Control-IQ technology 1.5, and to continue use for at least 12 consecutive months after study enrollment.
• * Agree to provide HbA1c result, obtained within the 6-month period prior to enrollment.
• * Ability for parent/guardian to respond to alerts and alarms, and to provide basic diabetes self-management.
• * Reside full-time in the United States.
• * Willingness to download the t:connect Mobile application to their smartphone and keep it active throughout the study if using a Tandem t:slim X2 pump. Participants who are unable to use the t:connect mobile application must be willing to manually upload their insulin pump data to Tandem Source every three months and at the completion of the study.
• * Participant's parent/guardian has read, understood and agreed to participate in the study, and has electronically signed the Informed Consent Form (ICF).
• * Use of any glucose-lowering therapy other than insulin.
• * A medical or other condition, or medications being taken that in the investigator's judgement would be a safety concern for participation in the study.