MAUDE Adverse Event Report: Tandem Diabetes Care t:slim X2 Insulin Pump with Control-IQ Technology; Alternate Controller Enabled Insulin Infusion Pump

Model Number	1000354
Medical Device Problem Code	Incorrect Measurement (1383)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	09/23/2026
Type of Reportable Event	Malfunction
Event or Problem Description
It was reported that insulin gauge displayed amount different than expected earlier in the day, showing 32 units when caller expected 145 units, with difference greater than 30 units.There was no reported impact to the customer¿s blood glucose level.Caller resolved issue by reloading same cartridge, and technical support advised caller to call back for troubleshooting if issue occurred again, which caller acknowledged.
Additional Manufacturer Narrative
In use at the time of the event: cgm model: unknown mobile os: ios / ios_iphone 15 pro max / unknown / ios_26.

• Brand Name: t:slim X2 Insulin Pump with Control-IQ Technology
• Common Device Name: Alternate Controller Enabled Insulin Infusion Pump
• Manufacturer (Section D): Tandem Diabetes Care; 12400 high bluff drive; san diego CA 92130
• Manufacturer Contact: john connell ; 12400 high bluff drive; san diego, CA 92130 ; +1(858)224-6281
• MDR Report Key: 50949147
• Report Number: 3013756811-2026-177877
• Device Sequence Number: 10348777
• Product Code: QFG
• UDI-Device Identifier: 00850006613793
• UDI-Public: (01)00850006613793(11)210508
• Combination Product (Y/N): N
• Initial Reporter State: NV
• Initial Reporter Country: US
• PMA/510(K) Number: K203234
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Reporter Type: Manufacturer
• Report Source: Consumer
• Type of Report: Initial
• Report Date (Section B): 09/30/2026

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Operator of Device: Lay User/Patient
• Device Model Number: 1000354
• Device Catalogue Number: 1006408
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: No
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 09/23/2026
• Initial Report FDA Received Date: 09/30/2026
• Was Device Evaluated by Manufacturer? (Y/N): No
• Date Device Manufactured: 08/05/2021
• Is the Device Labeled for Single Use? (Y/N): No
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Reuse
• Patient Sequence Number: 1
• Patient Age: 40 YR
• Patient Sex: Female
• Patient Weight: 125 LB