Multidistrict litigation is a legal procedure in United States federal courts in which lawsuits involving similar issues (common issues of fact) are consolidated in one court (called the MDL court) for the purpose of convenience and efficiency in pretrial matters, such as discovery. These lawsuits are generally returned to their original federal district courts for trial. Claims that are often the subject of multidistrict litigation are product liability claims against pharmaceutical companies, securities fraud cases, and airplane crashes.

Multidistrict litigation (MDL) is a federal legal procedure that allows for the consolidation of multiple lawsuits that share common factual issues to be transferred to a single federal district court. This process is designed to streamline pretrial proceedings, including discovery and motions, to improve efficiency and reduce the burden on the court system. In Missouri, as in other states, cases that are part of an MDL may originate from various federal district courts but are consolidated in one court for pretrial matters. After the pretrial phase, the cases are typically sent back to their original courts for trial. MDLs are commonly used for complex cases such as product liability suits involving pharmaceuticals, securities fraud cases, and major accidents like airplane crashes. The Judicial Panel on Multidistrict Litigation, a group of federal judges, decides whether cases should be consolidated under MDL and which district court will oversee the proceedings.