A Primer on MDLs - FAQs

What is multidistrict litigation?

Multidistrict litigation or “MDL” as it's known is the process that federal courts use to coordinate pretrial proceedings for cases with factual similarities. Congress has statutorily authorized multidistrict litigation through 28 U.S.C. § 1407.

The Judicial Panel on Multidistrict Litigation includes seven judges from throughout the country who are selected by the Chief Justice of the United States Supreme Court. The “Panel” decides whether to centralize related proceedings before a single federal judge and then which judge will receive those cases. To make this decision, the Panel considers many different factors such as whether discovery needs are similar, whether similar facts exist, the number of actions, and whether there are competing motions for class certification.

Once the Panel decides to transfer cases, they have to pick a judge to handle them. For this decision, they consider things like the location of discovery materials, the convenience of the witnesses, location of the majority of actions, knowledge of the transferee judge, and the willingness and motivation of a particular judge to handle an MDL docket.

The judge that the Panel selects to preside over related cases is called the “transferee judge.”

Chapter 1 of Mass Tort Deals: Backroom Bargaining in Multidistrict Litigation provides more details on what MDL is and what a plaintiff or her attorney might expect in an MDL situation.

What's the difference between a class action and MDL?

Multidistrict litigation is the process that federal courts use to coordinate related cases before a single judge. Sometimes that judge, the "transferee judge," will decide to certify a class action. Class certification must comply with Federal Rule of Civil Procedure 23. Rule 23 requires that class counsel adequately represent the class, that the class members are so numerous that joining them through conventional means is impractical, that class members' claims have common questions that can be answered collectively, and that class members' claims are typical of one another. In addition, to certify a Rule 23(b)(3) class, class members' claims must share a great deal in common. In the words of Rule 23, those common questions must predominate over individual questions. Most mass torts are not certified as class actions. To find out more about why so few mass torts are certified as class actions (and the trouble that this may cause), read Chapter 1 of Mass Tort Deals: Backroom Bargaining in Multidistrict Litigation.

What is a "lead lawyer" and why wasn't my attorney picked for a leadership role?

MDLs can include hundreds (and sometimes thousands) of plaintiffs. The transferee judge who presides over these cases isn't able to talk with each lawyer individually.

So, she selects a group of lead lawyers--lead counsel, plaintiffs' executive committees, liaison counsel, steering committees, and other lead roles. Those are the attorneys who do the majority of the work in a given proceeding.

Currently, judges use several factors to select leaders: experience, cooperative tendencies, and an ability to finance the lawsuits. (Large multidistrict proceedings can cost plaintiffs’ attorneys millions of dollars to develop.)

As the bubble charts below show, these factors tend to empower the same lawyers again and again. That can lead to trouble. To find out more, read Chapters 2 and 3 of Mass Tort Deals: Backroom Bargaining in Multidistrict Litigation.

How can I get my case out of an MDL proceeding?

Having a case sent back to its original court or "remanded" to its court of origin is extremely difficult. Historically, fewer than 3% of cases coordinated through an MDL proceeding are ever returned to the federal court in which they were filed. Procedurally, only the MDL Panel can remand a case. In theory, they could do this on their own. In practice, they do so only upon a suggestion of remand by the transferee judge. Chapters 5 and 6 of Mass Tort Deals: Backroom Bargaining in Multidistrict Litigation describe how the lack of remand (and the inability to threaten to take a case to trial) can hurt plaintiffs' cases. It likewise suggests several reform proposals, including episodic remands.

What's troubling about mass tort deals?

Judges and academics have long raised questions about arms-length bargaining and adequate representation in the class-action context, even though Rule 23 builds in some safeguards. In class actions, for example, judges have the authority to appoint class counsel; consider whether counsel adequately represents class members; ensure that any class settlement is fair, reasonable, and adequate; and award class counsel’s attorney’s fee. But worries about collusion, self-interest, and overreaching don’t disappear just because mass litigation can’t be certified as a class action. Instead, we might worry more because the judge lacks any clear-cut authority to police the proceedings in the same way. Those concerns can be exacerbated if repeat players exist leadership positions, which they do. That repeat players exist isn’t surprising in and of itself. Attorneys specialize all the time. It might be that they use their expertise to generate better outcomes for their clients. But playing the long game may also mean that repeat players develop working relationships with their opponents such that each side can use private settlement to bargain for what matters to them most from a self-interested standpoint. For corporate defendants and their lawyers, this means ending the litigation with the least cost. For lead plaintiffs’ lawyers, this typically means attorneys’ fees—specifically common-benefit fees (the fees they receive for the work they do on behalf of the group as a whole). As Chapter 3 of Mass Tort Deals details, repeat-player attorneys are prevalent in leadership positions on both the plaintiff and defense side in products-liability multidistrict proceedings. To the extent possible given that most of the mass-tort settlements were private, Chapter 2 examines the deals that these repeat players negotiated with one another. After confirming that one of the top five most connected repeat players participated directly in each settled proceeding’s leadership, Chapter 2 identifies the provisions within those settlements that are arguably more beneficial to plaintiffs’ lead lawyers or to the defendants than to the actual plaintiffs. How do these provisions work? To stymie the lawsuits against them, for example, defense corporations include settlement provisions designed to push as many plaintiffs as possible into the settlement program. These closure clauses might require plaintiffs’ lawyers to recommend that all their clients accept the settlement offer and, if the client refuses, take steps to withdraw from representing that client. To enter a settlement program, plaintiffs must typically dismiss their lawsuit. But those plaintiffs often don’t know what, if anything, they will receive under that program. So, plaintiffs may be giving up their lawsuit in exchange for no compensation whatsoever. For example, in litigation over the acid-reflux medicine Propulsid, out of the 6,012 claimants who entered into the settlement program, only 37 received any money. The rest received nothing, but had already dismissed their lawsuit as a condition of entering into the program. Those 37 plaintiffs collectively received little more than $6.5 million. The lead plaintiffs’ lawyers in Propulsid, however, negotiated their common-benefit fees directly with the defendant, Johnson & Johnson. Those attorneys received $27 million in common benefit fees. Much of the remaining funds then reverted back to Johnson & Johnson.Lead plaintiffs’ lawyers in Propulsid announced that they were creating a template for all future deals. Chapter 2 of Mass Tort Deals shows that they did exactly that. Considering settlements that occurred over a 14-year span, Chapter 2 shows that every deal contained at least one closure provision for defendants. Nearly all settlements also contained some provision that increased lead plaintiffs’ lawyers common-benefit fees. Bargaining for attorneys’ fees with one’s opponent is a troubling departure from traditional contingent-fee principles, which are designed to tie lawyers’ fees to their clients’ outcomes. In short, Mass Tort Deals raises the concern that as repeat players influence practices and norms in mass torts, they may undermine plaintiffs’ ability to freely consent to the settlement. That may or may not affect the substantive outcome, however. Unfortunately, most of the data on how plaintiffs fared under settlement programs was not publicly available.

Which proceedings are included in the dataset?

Here is a list of the proceedings in the dataset.

All of the documents that the book cites (and many, many more) are available (and searchable) via the MDL Docs page, courtesy of the University of Georgia School of Law. Please note that the folders dedicated to each proceeding do not contain anything close to all of the documents filed in that proceeding. Instead, they include the documents that underlie the data and arguments in Mass Tort Deals: Backroom Bargaining in Multidistrict Litigation.

New documents that may be of interest to the public and the press will be added from time to time, but again, the documents do not include all of the documents or orders in any proceeding.

Where can I find historical data on MDL proceedings?

Dr. Margaret S. Williams, a senior researcher at the Federal Judicial Center, has posted a wonderful and highly informative paper called The Effect of Multidistrict Litigation on the Federal Judiciary over the Past 50 Years.

I'm a plaintiff in an MDL, what do I need to know?

I've written a relatively short "primer" for plaintiffs who find themselves swept up in an MDL. It covers the following topics: hiring a lawyer; what to look out for when signing a retainer agreement; what multidistrict litigation is; why your lawyer doesn't want you to speak pubicly; what plaintiff fact sheets are; why your lawyer might push you to settle your lawsuit; and why you might have trouble finding a lawyer to take your case. Mass Tort Deals is also written in a way that's accessible to those with and without legal expertise.


Basic MDL Statistics

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MDLs by the Numbers

As of April 15, 2019, 205 MDL proceedings were pending in federal courts across the country. The majority of these proceedings are products liability, antitrust, or miscellaneous.


Click on each image for an interactive version. 

MDL Proceedings by Total Actions (Histor

Products-Liability Proceedings

Looking at the total number of actions filed within these 205 MDL proceedings shows that between 92-95% of all the actions filed in MDLs are products liability.

New filings in MDLs currently make up between 15-21% of all new federal civil filings.

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How Do Products-Liability Proceedings End?

Of the products-liability proceedings pending on the MDL docket in May of 2013, most ended in private, aggregate settlements.

Proceedings that principally allege economic harms are often certified as class actions.

Lead Lawyers & Repeat Players


Judges aren't able to speak directly with every lawyer in massive multidistrict proceedings. So, they appoint lead lawyers on behalf of the plaintiffs.

The number of leaders varies by proceeding, with lead counsel as the most powerful position.

As indicated by the graphs below, both plaintiff and defense leadership positions tend to be populated by repeat players.

Click on the graph for an interactive version.

Leadership Appointments by MDL Proceedin

Some lawyers appear time and again as lead lawyers in MDL products-liability proceedings.


They are pivotal in negotiating and designing mass-tort deals.

Here are the major players within the book's dataset.

Click on the bubble chart for a list and an interactive version.

Repeat Players in MDL within the Dataset

Judges tend to appoint lawyers from the same plaintiff and defense law firms to lead products-liability MDLs.

Who are those go-to firms?

Here's a bubble chart of the law firms that were appointed the most frequently within the dataset.

Click on the chart for a list and an interactive version.

Repeat Players by Law Firm - clean.png

Products-liability proceedings are some of the largest proceedings in federal court.

Proceedings with the most actions include asbestos and the pelvic-mesh proceedings before Judge Joseph Goodwin.

Click on the bubble chart for a list and an interactive version.

MDL Proceeding by Size v.2.png

Mass Tort Settlement Provisions

Mass Tort Deals marshals a wide array of empirical data on multidistrict litigation to suggest that the systemic lack of checks and balances for these cases may benefit everyone but the plaintiffs.


Analyzing mass-tort cases consolidated over 22 years and settled over 14, including the deals insiders negotiate, the “common-benefit” attorneys’ fees that the lead plaintiffs’ attorneys receive to run the litigation, and the judicial rulings, reveals a troubling pattern: repeat plaintiff and defense attorneys persistently benefit from the current system.


Defense lawyers are able to end sprawling lawsuits on their corporate client’s behalf while lead plaintiffs’ lawyers broker deals that reward them handsomely and sometimes pay litigants very little.

By identifying settlement provisions that one might argue principally benefit the repeat players, Mass Tort Deals examines the publicly available nonclass settlements these elite lawyers designed. All of those settlements can be downloaded by clicking on the links below.


Every settlement features at least one closure provision for corporate defendants (all listed and described below), and nearly all contain some provision that increases lead plaintiffs’ lawyers’ common-benefit fees.


Bargaining for attorneys’ fees with one’s opponent is a stark departure from traditional contingent-fee principles, which are designed to tie lawyers’ fees to their clients’ outcome. Based on the evidence available, there is reason to be concerned that when repeat players influence the practices and norms that govern multidistrict proceedings and settlement programs—when they “play for rules,” so to speak—the rules they develop may principally benefit them at plaintiffs' expense.

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Settlement Agreements

(Click below to view)

Lead Plaintiffs' Lawyers' Fees Negotiated with Defendant


All Settlements Except NuvaRing and American Medical Systems (data unavailable)

Whatever money is left in a settlement fund after the program doles it out then reverts to the corporate defendant, which can incentivize defendants to craft strict recovery criteria.

All Settlements

If fewer than the desired percentage of plaintiffs enter the settlement program, the corporate defendant may call the deal off.  Required participation rates ranged from 85-100%

Yasmin/Yaz I & II, DePuy ASR I & II, Vioxx, NuvaRing, Actos, Zimmer Durom Hip Cup

Dealmakers jointly petition the judge to issue a census that requires all attorneys with a case in the MDL proceeding to register all their clients' state and federal claims, whether filed or unfiled, so that the corporate defendant can use that number as the denominator for calculating compliance with the walkaway percentage.

By plaintiffs' attorney: Propulsid I & II, Vioxx, Fosamax, American Medical Systems

By defendant: DePuy ASR I & II

By plaintiffs' attorney: Propulsid I & II, Vioxx, Fosamax, American Medical Systems

By defendant: DePuy ASR I & II

Mandatory: Propulsid I & II, Vioxx, Fosamax, American Medical Systems

Best efforts: Yasmin/Yaz I & II, DePuy ASR I & II, NuvaRing, Actos

All participating attorneys must recommend that all their clients enter into the settlement program.

DePuy ASR I & II, Zimmer Durom Hip Cup, Fosamax, American Medical Systems

By aiming to prevent new lawsuits from being fied once a settlement is announced, these provisions take various forms, such as reducing payouts to those without counsel on the settlemnett date, restricting lawyer advertising, or affirming that participating lawyers have no intent to solicit new clients.

Propulsid I & II, DePuy ASR I & II

Whatever money is left in a settlement fund after the program doles it out then reverts to the corporate defendant, which can incentivize defendants to craft strict recovery criteria.


Index to Data Available in Mass Tort Deals

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Learn More

List of MDL Proceedings

Products-liability proceedings pending on the MDL docket as of May 2013

Data on Repeat Players

The password for this page is available to purchasers (page 5, footnote 4 of Mass Tort Deals).

Social Network Analysis

Links to in-depth views of the connctions between repeat players and MDL proceedings. Analysis by Dr. Margaret Williams

MDL Orders and Filings

All of the filings, transcripts, and orders collected as part of the analysis in Mass Tort Deals are available, searchable, and downloadable here.