Multidistrict litigation (MDL) is quietly reshaping the legal and insurance landscape in the United States. Originally just a procedural tool for lawyers, MDL now plays a major role in handling large groups of related lawsuits in federal courts. This method allows similar claims—often tied to mass disasters or product exposures—to be grouped together under one judge for coordinated handling. This shift is having a big impact on insurers, brokers, and policyholders, especially as the 2026 court calendar sees delays in major bellwether trials.
Bellwether trials are key because they test a few representative cases first. The results help shape how thousands of other cases might settle or be handled. For insurers, these early cases can reveal how costly the broader exposure might be. Some MDLs have grown enormous. The 3M Combat Arms Earplug litigation, for example, once included 260,000 cases and led to a $6 billion settlement. Other notable MDLs include the Roundup herbicide cases and recent settlements related to defective infant sleepers.
Data from Verisk shows that in just the last two years, 48 MDLs were closed, with nearly half ending in settlements. These cases spanned a range of issues, including natural disasters, medical devices, and data breaches. But the real financial strain for insurers comes from the long duration of these lawsuits, which tend to last for years and rack up mounting defense costs.
Product liability cases continue to dominate the MDL scene. Cosmetics, pharmaceuticals, and medical devices are frequently involved, along with long-running disputes over firefighting foam and environmental contamination. Cybersecurity-related MDLs, while smaller right now, are also becoming more common.
Some MDLs are worth watching closely in 2026:
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The Johnson & Johnson Talcum Powder case tops the list with more than 67,000 cases, growing quickly as new claims come in. It’s the largest active MDL, with the first federal trial expected next year. State cases are also moving, pointing to a long road ahead for defense and settlements.
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The Aqueous Film-Forming Foam (AFFF) MDL involves over 13,900 cases linked to cancer and other health issues caused by firefighting foam. This environmental litigation is closely monitored because of its wide-reaching impact on insurers and municipalities.
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Hair Relaxer Products cases, alleging cancer risks from chemical hair treatments, have surpassed 10,000 claims. This is a fast-growing disputed area with high stakes for reputation and losses.
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The Roundup (Glyphosate) litigation, even after large settlements, still has 4,000 cases pending. It shows how these MDLs can linger long after headline deals are made.
- A new and rapidly expanding case involves GLP-1 weight-loss and diabetes drugs, with stomach and intestinal injuries alleged. This case has nearly tripled in size over the past year, signaling emerging pharmaceutical risks.
MDLs are no longer just legal procedures overlooked by most people; they have become central to how massive liability cases are handled. For the insurance industry, keeping an eye on these cases will be crucial as they continue to influence costs, legal strategies, and settlement trends in the years ahead.