Tandem Diabetes Care, Inc. has issued an insulin pump safety notice for select t:slim X2 insulin pumps. The correction addresses a speaker-related issue that may result in an error known as “Malfunction 16,” which causes insulin delivery to stop and communication with the continuous glucose monitoring (CGM) device to end.
Why the Insulin Pump Safety Notice Was Issued
When this error occurs, insulin delivery is discontinued, and the insulin pump can no longer exchange data with the CGM system. As a result, users may lose access to real-time CGM Estimated Glucose Values and CGM trends. If the interruption in insulin delivery is not addressed, it can lead to hyperglycemia. In some cases, users may require medical intervention or hospitalization. This insulin pump safety notice underscores the potential risks of device malfunction for diabetes patients.
Reported Adverse Events Under the Insulin Pump Safety Notice
Tandem has reported 700 confirmed adverse events linked to this issue. These include verified instances of high blood sugar and situations that required medical assistance. The company has also reported 59 injuries, but stated that no deaths have occurred in connection with the malfunction. Tandem noted, “If not addressed, this could result in hyperglycemia due to discontinuation of insulin delivery, real-time CGM Estimated Glucose Values, and CGM trends.” The insulin pump safety notice further emphasizes the need for prompt corrective actions.
Customer Notifications and Instructions
Between July 22 and 24, 2025, the company sent out notifications to affected customers in the United States. These notices provided instructions for users on how to respond if a Malfunction 16 alert is triggered. The insulin pump safety notice advised users to remain vigilant and take immediate corrective measures to avoid health risks.
Regulatory Oversight and Software Update
Tandem has notified the U.S. Food and Drug Administration, as well as regulatory agencies outside the United States, regarding the correction. In addition to the notification, Tandem plans to release a software update. This update is intended to enhance early detection of speaker failure and introduce persistent vibration alerts, with the goal of reducing potential safety risks. Once the software becomes available, Tandem will inform all insulin pump users and ask them to complete the update. Customers in the United States who have questions regarding the correction can contact Tandem Diabetes Care’s Technical Support Team via mobile and email. Support is available 24 hours a day, seven days a week. Customers located outside the United States are advised to contact their local distributors for assistance under the insulin pump safety notice framework.
Overview of Tandem’s Insulin Pump Safety Notice
Shares of Tandem Diabetes Care fell more than 27% in premarket trading following the announcement. The correction was issued in response to the Malfunction 16 defect, which can interrupt insulin delivery and CGM communication, with potential consequences including high blood sugar. The company reiterated that although there have been confirmed injuries and medical interventions, no fatalities have been reported in connection with this insulin pump safety notice.
Importance of Device Safety in Diabetes Management
This insulin pump safety notice highlights the importance of strong monitoring and reporting systems within the medical device industry. Patients with diabetes rely heavily on consistent insulin delivery, and even short interruptions can lead to serious health complications. Manufacturers are under increasing pressure to ensure device reliability, issue proactive safety updates, and maintain open communication with both regulators and users.
Experts emphasize that while software updates and corrective measures can reduce risks, long-term trust between patients and device makers is built on transparency and timely responses. The t:slim X2 update serves as a reminder that medical technology, while life-changing, must always prioritize patient safety above all else.
