The Short Answer
Three terms, three distinct meanings — even if they are frequently used interchangeably in conversation.
Class Action
Cornell LIIA procedural device that lets one or more plaintiffs sue on behalf of a larger class of people who suffered the same wrong. Courts can manage lawsuits that would otherwise be difficult to handle if every class member had to appear as a named plaintiff.
MDL (Multidistrict Litigation)
28 U.S.C. § 1407 / JPMLA federal procedure under 28 U.S.C. § 1407 that temporarily transfers civil actions with common questions of fact to one district for coordinated or consolidated pretrial proceedings. The JPML decides which cases transfer and selects the transferee court and judge.
Mass Tort
Federal Judiciary MaterialsA broad term for many individual injury claims arising from the same or similar product, event, or conduct. Not one single procedural rule — federal judiciary materials treat mass torts and class actions as related but distinct categories of complex litigation.
In practice, many dangerous drug and medical device cases are talked about as "mass torts," while being managed through MDL proceedings — and they are often not traditional class actions.
What Is a Class Action?
A class action allows one or more named plaintiffs to litigate on behalf of a larger class when the claims are sufficiently similar. Courts can manage lawsuits that would otherwise be unmanageable if every class member had to appear as a named plaintiff.
At a practical level, class actions are often associated with:
One representative case structure
One proposed class of similarly situated plaintiffs
Common issues predominating across the group
Outcomes that can bind absent class members if the class is certified
That does not mean every large lawsuit is a class action. People love saying "class action" because it is the only term many of them know. Reality remains irritatingly more specific.
What Is a Mass Tort?
A mass tort usually refers to many individual claims arising from the same product, event, or conduct — especially where many people allege injury but the details of each person's injury, exposure, causation, and damages may differ. Federal judicial materials treat mass torts as part of the broader universe of complex litigation, not simply as class actions with a different name.
In practical terms, mass tort litigation often involves:
Many plaintiffs
Dozens, hundreds, or thousands of individual claimants.
Similar allegations
Each plaintiff alleges harm from the same or substantially similar product or conduct.
Shared factual themes
Common questions of product safety, manufacturer conduct, or regulatory history.
Individual differences
Each claimant's exposure, injury, medical history, and damages may differ significantly.
That last point — individual differences — is precisely why dangerous drug and device cases often fit better into a mass-tort framework than into a single uniform class action model.
What Is an MDL?
An MDL, or multidistrict litigation, is a federal procedure created by Congress in 28 U.S.C. § 1407. It temporarily transfers multiple civil actions with common questions of fact to one district for coordinated or consolidated pretrial proceedings. The JPML decides whether cases pending in different federal districts should be transferred — and selects the transferee court and judge.
Why MDL Matters
Discovery can be coordinated across all related cases
Pretrial rulings can be centralized to avoid inconsistent results
Efficiency improves for courts, parties, and counsel
Common factual questions are handled in one place
An MDL is not automatically a class action. It is a case-management structure for pretrial proceedings. Individual cases retain their individual character — and individual proof requirements — within the MDL framework.
Why Drug and Device Cases Are Often Mass Torts Instead of Class Actions
Dangerous drug and medical device claims often involve significant individual variation. That makes many of these cases poor candidates for one-size-fits-all treatment.
In practice, many product-liability claims are better understood as mass torts, often coordinated through MDL, rather than as classic class actions. Federal judicial materials addressing MDL management and related proposed class actions reflect exactly this kind of complexity.
Why the Distinction Matters to Users
These structures can affect:
How cases are filed
Whether a claim enters a consolidated MDL or proceeds in individual federal or state courts.
Where pretrial proceedings happen
MDL centralizes pretrial in one district; individual cases may proceed elsewhere after pretrial.
Whether your case stays individually evaluated
Mass tort cases often retain individual proof requirements even within a larger MDL structure.
How discovery and motions are managed
MDL coordinates common discovery; individual-specific issues are handled separately.
Whether settlements or bellwether processes may emerge
MDLs often involve bellwether trials and global settlements that affect how individual claims resolve.
For most users, the practical takeaway is simpler:
If a drug or device claim is part of a broader litigation structure, that does not necessarily mean you are just one faceless name in a giant pile. Many mass-tort cases still turn heavily on individual proof, individual injury, and individual damages. That is why records, timeline, diagnosis, and product identification still matter even when there is already a large litigation structure in place.
When People Confuse These Terms
Three common assumptions that do not hold up under scrutiny.
"If it's a big lawsuit, it must be a class action."
Not true. Many big product cases are mass torts or MDLs, not traditional class actions.
"If it's in an MDL, I automatically have a case."
Also not true. MDL is a procedural structure, not proof that every claimant has a viable case.
"Mass tort just means class action with a fancier name."
No. Mass-tort practice often involves many individual claims with shared facts but important personal differences. Federal judiciary materials treat these as distinct complex-litigation realities.
How MD Law Uses This Distinction
This page supports the rest of the platform by helping users move from product name, to alleged injury, to litigation structure, to qualification, to case review.
Intended User Journey
That way users are not forced to pretend they understood "MDL" from context clues and legal smoke.
Active Lawsuits
Current drug and device litigation tracking.
Dangerous Drug Lawyer
Attorney resource for pharmaceutical claims.
Defective Medical Device Lawyer
Attorney resource for device-related claims.
GLP-1 Lawsuits
Ozempic, Wegovy, and Mounjaro litigation hub.
Drug Recall Lawsuits
How recalls differ from viable lawsuits.
How Case Evaluation Works
What happens after you submit your information.
Mass Tort vs Class Action FAQs
Clear answers to the most common questions about class actions, mass torts, and MDL.
Understand the Structure Before You Assume the Outcome
If you believe a drug or device caused serious harm, it helps to know whether the claim is being discussed as a class action, a mass tort, or part of an MDL. The structure does not prove the case, but it does change the path.
Structured. Serious. Built for medically and legally complex product claims.