The goal of this surveillance study is to collect real-world data on adults and youth with type 1 diabetes (T1D) using twiist(TM) for insulin delivery.

Inclusion Criteria:

• Willing and able to provide informed consent (or a parent or other legally authorized representative)
• Age ≥ 6 years old
• Diagnosis of T1D
• Currently using twiist AID system, with initiation of twiist within 90 days of enrollment
• Willing to only use an insulin approved for the pump
• Residing in United States
• Willing to use twiist in accordance with the user manual
• Willing to have the study use the twiist data and any information that has been provided to Sequel Medtech, LLC or customer support since twiist was started
• Willing to complete surveys at the beginning of the study and then monthly for 12 months
• Willing to be contacted if clarification or further information is needed for any events reported on a survey or to customer support
• Willing to provide medical records or sign a record release for any hospitalizations
• Has cell service or if not, will have access to WIFI at least once a week
• For females, not pregnant or planning pregnancy in the next 12 months
• Able to speak and read English
• Able to obtain documentation of HbA1c result obtained within 6 months prior to twiist initiation

Exclusion Criteria:

• Any form of diabetes other than T1D
• Receiving dialysis for end-stage renal disease

Participants who are diagnosed with Type 1 Diabetes, are at least 6 years old, and have been prescribed and are currently using the twiist system.