New mass tort procedural rules have taken effect

On December 1, 2025, new Federal Rule of Civil Procedure 16.1 took effect, addressing a gap in the Federal Rules concerning how multidistrict litigation (MDL) should commence following consolidation. MDL is a procedural mechanism that allows civil actions involving one or more common questions of fact to be transferred to a single district court for pretrial proceedings. The Multidistrict Litigation Act, 28 U.S.C. § 1407, adopted in 1968, provides the vehicle for the Judicial Panel on Multidistrict Litigation (JPML) to transfer one or more actions for coordinated or consolidated pretrial proceedings. Since the creation of the JPML, MDLs have become a dominant part of the federal civil docket and now cover more than half of all pending civil cases in federal court.

Noting the scale and complexity of MDL, the Advisory Committee on Civil Rules established an MDL subcommittee in 2017 to assess whether tailored rules specific to MDL were needed. For decades, transferee courts had managed MDLs through ad hoc practices, relying on individual judges’ standing orders and judicial preferences to govern leadership appointments, discovery protocols, and filing of pretrial motions. Rule 16.1, a product of the MDL subcommittee’s work, begins to fill this gap as the first federal rule to provide structured guidance for early pretrial MDL proceedings. It establishes uniform procedures for initial case management conferences to address discovery protocols, leadership appointments, pretrial motions, and more. The key takeaways are as follows:

Rule 16.1 sets forth new procedures for initial case management.

Rule 16.1 provides that once the JPML transfers an MDL to a transferee court, the transferee judge presiding over the new MDL “should” promptly schedule an initial management conference and order the parties “to submit a report to the court before the conference.” The parties’ report must address a variety of pretrial issues, including:

• whether leadership counsel should be appointed and how;
• any previously entered orders that should be vacated or modified;
• a schedule for additional case management conferences; 
• how to manage the direct filing of new actions in the MDL; and
• whether related actions have been or are expected to be filed in other courts.

Unless the court orders otherwise, the report must also address initial views on:

• whether consolidated pleadings should be prepared;
• how and when the parties will exchange information about the factual bases for their claims and defenses;
• discovery plans and any anticipated difficulties that may arise;
• likely pretrial motions;
• whether the court should consider any measures to facilitate resolving some or all actions before the court; 
• whether any matters should be referred to a magistrate judge or a special master; and
• the principal factual and legal issues likely to be presented.

The parties are also permitted, but not required, to include in the report “any other matter” that they wish to bring to the court’s attention. Following the initial conference, the court must issue its case management order,setting the road map for the procedures and scheduling on how the case will move forward. The court’s order can be modified if needed at a later date.

Rule 16.1 facilitates early vetting of claims.

Rule 16.1 emphasizes early vetting and information sharing, including the factual bases for each side’s claims and defenses. The Advisory Committee Notes explain that the timing and scope of these exchanges may vary depending on factors such as the types of cases before the court. They also acknowledge that transferee courts have ordered parties to provide their claims and defenses outside the standard discovery rules, and in some instances, transferee judges have required exchanges under other rules, such as Rule 33 (interrogatories) or Rule 34 (document requests). In some circumstances, after considering whether the party whose claim or defense is at issue has reasonable access to the necessary information, the court “may find it appropriate to employ expedited methods to resolve claims or defenses that are not supported following the required information exchange.” Ultimately, by encouraging these early exchanges, Rule 16.1 seeks to promote prompt identification and dismissal of nonmeritorious claims at the outset of litigation.

Rule 16.1 is an early step toward procedural certainty in MDLs.

Rule 16.1 marks a meaningful step toward greater procedural uniformity and coherence in MDL. It also provides flexibility and recognizes the broad discretion needed for MDL judges to shape pretrial proceedings appropriately. Whether it effectively narrows the documented variability across MDL courts remains to be seen, but its adoption is a step in the right direction and a recognition that MDLs — comprising over half of the federal civil docket — require clearer procedural scaffolding.