Abbott Faces Class Action Lawsuit Over FreeStyle Libre 3 Sensors Not Working

Company also faces individual product liability lawsuits due to FreeStyle Libre 3 sensor problems causing serious injuries.

A union health benefit plan has filed a class action lawsuit against Abbott, alleging the company sold defective FreeStyle Libre 3 glucose sensors that failed to provide accurate readings, despite marketing the devices as reliable enough to replace traditional fingerstick testing.

The complaint (PDF) was brought by the International Union of Operating Engineers Local 501 Security Fund in the U.S. District Court for the Central District of California on August 14. It names Abbott Diabetes Care Inc. and Abbott Laboratories as defendants.

The fund provides health benefits to thousands of union members and their dependents and says it made reimbursements for defective FreeStyle Libre 3 and FreeStyle Libre 3 Plus sensors that were not working.

FreeStyle Libre 3 Sensor Problems

FreeStyle Libre 3 and FreeStyle Libre 3 Plus devices are wearable continuous glucose monitoring systems that track glucose levels throughout the day and send readings to a smartphone or reader. The products are intended to help people with diabetes make insulin dosing and other treatment decisions while reducing the need for routine finger-stick testing.

However, Abbott announced a recall of certain FreeStyle Libre 3 sensors in July 2024, due to the potential for falsely high readings. In September 2024, the U.S. Food and Drug Administration (FDA) assigned the action a Class I recall, its most serious designation.

Abbott initiated a second medical device correction in November 2025, involving more than 3 million FreeStyle Libre 3 and Libre 3 Plus sensors produced on a single manufacturing line. In that case, the company determined the affected devices could report falsely low glucose levels, a problem associated with hundreds of serious adverse event reports and several deaths.

The FDA later designated that action as a Class I recall in January 2026, indicating use of the affected sensors could pose a risk of serious injury or death.

Amid those safety concerns, a growing number of FreeStyle Libre lawsuits now allege inaccurate sensor readings caused users to make improper diabetes treatment decisions, resulting in complications such as hypoglycemia, hyperglycemia and diabetic ketoacidosis (DKA).

DKA is a potentially life-threatening condition that occurs when insufficient insulin prevents the body from properly using glucose for energy. The body instead begins breaking down fat, producing ketones that can build up in the blood and, without timely treatment, lead to severe dehydration, organ damage, unconsciousness or death.

Abbott FreeStyle Libre 3 Class Action Allegations

According to the complaint, the International Union of Operating Engineers Local 501 Security Fund is an end payor, which means it reimbursed some or all of the costs of sensors used by its covered members. As a result, the lawsuit is seeking compensation for economic losses rather than individual physical injuries.

Court filings allege that the fund made reimbursement decisions based on Abbott’s representations that the sensors were safe, accurate and reliable. It goes on to point out that health plans typically pay most of the cost of FreeStyle Libre sensors, which retail for roughly $224 to $235 for a 28-day supply.

The fund maintains it and other health plans would not have paid for the affected sensors, or would have paid substantially less, if Abbott had disclosed that certain lots of the company’s FreeStyle Libre 3 sensors were not working.

It specifically attacks Abbott’s “no fingersticks” marketing, arguing that the representation was misleading because manufacturing problems could make fingerstick confirmation necessary for patient safety.

The complaint alleges Abbott knew of the potential for FreeStyle Libre 3 sensor problems through internal testing and post-market surveillance before publicly announcing corrective action. It also characterizes the shift from the 2024 recall for falsely high readings to the 2025 falsely low readings recall as evidence of broader manufacturing and quality-control failures.

“Plaintiff alleges that Abbott knew, or was reckless in not knowing, about the defects at all relevant times, specifically at the time Plaintiff and the other members of the proposed Class acquired their Sensors or related accessories—such as overpatches, adhesives, additional test strips, insulin pumps, and/or Freestylecompliant cell phones—required for the Sensors themselves or necessary because of the Sensors’ defects.”

— Union of Operating Engineers Local 501 Security Fund v. Abbott Diabetes Care Inc. et al.

The fund seeks damages on behalf of a nationwide class of entities that purchased, paid for or reimbursed the cost of FreeStyle Libre 3 or Libre 3 Plus sensors covered by Abbott’s November 2025 recall and the FDA’s subsequent Class I recall designation in February 2026, dating back to May 1, 2024.

Allegations raised in the filing include fraudulent omission or concealment, unjust enrichment, breach of express and implied warranties, violations of California consumer protection laws and violations of the Magnuson-Moss Warranty Act. The lawsuit seeks actual damages, restitution, attorneys’ fees and other relief.

FreeStyle Libre 3 Sensor Lawsuits

While this complaint focuses on financial losses allegedly suffered by consumers and health plans, Abbott also faces product liability lawsuits brought by individuals who claim FreeStyle Libre 3 sensor problems caused serious injuries after they relied on faulty data to make insulin dosing and treatment decisions.

Individuals who suffered serious health problems after using a recalled FreeStyle Libre 3 or FreeStyle Libre 3 Plus continuous glucose monitor may be eligible to seek financial compensation. Injuries linked to inaccurate glucose readings may include:

• Wrongful death
• Severe hypoglycemia
• Seizures
• Confusion
• Loss of consciousness
• Diabetic ketoacidosis (DKA)
• Other serious metabolic complications requiring hospitalization

FreeStyle Libre 3 lawyers are reviewing potential claims for individuals and families nationwide who experienced complications after relying on inaccurate sensor readings. Case evaluations are available at no cost, and attorneys collect legal fees only if compensation is recovered.

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