Written by If you were injured by a defective product or dangerous drug, you may have heard the terms MDL and class action used interchangeably. They are not the same thing. Understanding the difference between MDL and class action lawsuits matters because it determines how your case is handled, how your damages are calculated, and what you can expect at the end of the process.
This article provides general legal information; consult a licensed Illinois attorney for advice specific to your situation.
What Is a Class Action?
A class action is a lawsuit filed on behalf of a large group of people who have suffered similar harm. Federal Rule of Civil Procedure 23 governs class actions in federal court, and 735 ILCS 5/2-801 establishes the requirements for class actions in Illinois state court. In a class action, one or a few named plaintiffs represent the entire class. If the case is certified, all class members are bound by the outcome unless they affirmatively opt out.
The defining characteristic of a class action is that individual damages are not separately determined. The total recovery is divided among class members, typically on a pro rata basis or according to a distribution formula. This works well when individual damages are small and uniform — consumer fraud cases, for example, where each person overpaid by a modest amount. It works poorly for personal injury cases where one person lost a limb, another developed cancer, and a third had only minor side effects. A shared recovery does not fairly compensate people with vastly different injuries.
What Is an MDL?
Multidistrict litigation (MDL) is a federal procedural tool created under 28 U.S.C. § 1407. When many similar cases are filed in federal courts across the country — think thousands of plaintiffs injured by the same pharmaceutical drug or medical device — the Judicial Panel on Multidistrict Litigation (JPML) can consolidate those cases before a single federal judge for coordinated pretrial proceedings.
The key word is pretrial. MDL consolidation handles discovery, motions to dismiss, and case management together, which saves enormous time and prevents inconsistent rulings. But each individual case retains its own identity. Your case is yours. Your damages are determined based on your specific injuries, your medical bills, your lost wages, and your particular circumstances. If pretrial proceedings do not resolve the case through a global settlement, your case is sent back to the federal district where it was originally filed for trial.
MDL vs. Class Action: Side-by-Side Comparison
The table below outlines the core differences between these two litigation structures:
| Feature | MDL | Class Action |
|---|---|---|
| Governing law | 28 U.S.C. § 1407 | FRCP 23 / 735 ILCS 5/2-801 |
| Individual case identity | Preserved — your case is yours | Merged — you are part of the class |
| Damages | Determined individually | Shared pro rata across the class |
| Opt-out option | Not applicable (you file your own case) | Yes — class members can opt out |
| Common use | Defective drugs, medical devices, toxic torts | Consumer fraud, small uniform losses |
| Trial | Individual cases can go to trial in home district | Single trial or settlement binds the class |
Why Most Mass Tort Injury Cases Are MDLs, Not Class Actions
Courts have consistently found that personal injury cases involving different types and degrees of harm do not meet the requirements for class certification under FRCP 23. The injuries are too individualized. A person who developed a serious autoimmune disorder from a drug cannot have their damages lumped together with someone who experienced only minor side effects.
MDL is the standard structure for major mass tort cases. The JPML tracks active MDLs, which at any given time include hundreds of thousands of individual cases covering drugs, medical devices, consumer products, and environmental contamination. Active MDLs have included litigation over opioids, talcum powder, CPAP machines, hernia mesh, and other widely used products.
For plaintiffs, MDL is generally preferable for serious injury cases precisely because your damages stay individual. A global settlement in an MDL is negotiated to include a settlement matrix — a framework that assigns different compensation tiers based on diagnosis, severity, duration of use, and other factors specific to each plaintiff. You are not splitting a flat pot equally with everyone else.
What This Means for Illinois Injury Victims
If you were injured by a product that has harmed many other people, the practical steps are similar regardless of whether an MDL or class action is involved. You should consult an attorney promptly, preserve all evidence of your injuries and your use of the product, and document your medical treatment carefully.
If an MDL is already established, your attorney will file your individual case in the appropriate federal court and have it transferred to the MDL docket. If a class action exists, your attorney can advise you whether joining, opting out, or filing a separate individual claim is more advantageous given the nature and severity of your injuries.
For more information on how Illinois handles these types of claims, see the overview of mass tort and product liability claims in Illinois.
Talk to a Chicago Attorney — Free Consultation
If you were injured by a defective product, dangerous drug, or medical device, Phillips Law Offices can help you understand whether your claim is part of an existing MDL, a class action, or best pursued as a standalone case. Call (312) 346-4262 or visit our contact page for a free, no-obligation consultation.