Tandem Diabetes Care Issues Urgent Correction for t:slim X2 Insulin Pumps Due to Potential Malfunction

The U.S. Food and Drug Administration has identified an urgent correction for certain Tandem Diabetes Care t:slim X2 insulin pumps, classifying it as the most serious type of recall. This action is necessary due to a potential issue with speaker wiring that could lead to a malfunction, halting insulin delivery and potentially causing serious harm, including death, if the device is not addressed. The correction involves a software update and does not require immediate removal of the pumps unless a malfunction occurs.

The problem, known as a “Malfunction 16” error, arises from a wiring issue within the pump’s speaker. This error can cause the device to stop functioning and cease insulin delivery. Without insulin, individuals managing diabetes could experience dangerously high blood sugar levels (hyperglycemia), which in severe cases can lead to the need for medical intervention, hospitalization, or even be fatal. To date, 59 injuries have been reported in connection with this issue, though no deaths have been reported.

Tandem Diabetes Care began notifying affected customers on July 22, 2025, with an Urgent Medical Device Correction letter. The company is recommending that all users with affected pumps confirm their device’s serial number against a provided list on tandemdiabetes.com/mal16-2025. Users are urged to complete an online form acknowledging receipt of the notice and to keep a backup method of insulin delivery readily available, as advised by their physician and outlined in their pump’s training materials.

For individuals whose pumps have not yet experienced the Malfunction 16 error, Tandem advises continuing to use their pumps as directed, but with added precautions. It is recommended to use the Tandem t:slim mobile app with push notifications enabled, as these notifications can alert users if a malfunction occurs. Users of Dexcom continuous glucose monitors are also advised to use the Dexcom mobile app as a secondary alert system. If users are unable to download or use these mobile applications, they should contact Tandem Diabetes Care for assistance.

In the event that a Malfunction 16 alert is received, users should immediately acknowledge the alarm by pressing “Silence Alarm.” They should then contact Tandem Diabetes Care at 1-877-801-6901 or Techsupport@tandemdiabetes.com to arrange for a replacement pump and switch to an alternative method of insulin delivery as directed by their healthcare provider. Regular blood sugar monitoring is also crucial to ensure glucose levels remain within a safe range.

Tandem Diabetes Care is developing a software update designed to improve early detection of speaker failures and introduce persistent vibration alerts. Affected pump users will be notified by the company when this update becomes available for installation. The t:slim X2 insulin pump is used by individuals aged two and older to manage diabetes by delivering insulin subcutaneously to help regulate blood glucose levels.

Customers in the U.S. with questions regarding this correction can contact Tandem Diabetes Care Customer Technical Support at 1-877-801-6901 or by email at Techsupport@tandemdiabetes.com. A comprehensive list of affected device catalog numbers and their corresponding Unique Device Identifiers (UDIs) is available.

Article by Mel Anara, based upon information from the U.S. Food and Drug Administration.

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