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.

In Alabama, as in all states, multidistrict litigation (MDL) is a federal legal procedure governed by federal law, specifically 28 U.S.C. § 1407. This statute allows for civil actions involving one or more common questions of fact that are pending in different federal districts to be transferred to a single federal district court for coordinated or consolidated pretrial proceedings. The goal is to streamline the process, prevent duplicative discovery, and avoid inconsistent pretrial rulings. The Judicial Panel on Multidistrict Litigation, a group of federal judges, decides whether cases should be consolidated under MDL and to which court they should be transferred. After the pretrial phase, the cases are typically sent back to their original courts for trial. MDLs are common in cases involving product liability, such as those against pharmaceutical companies, as well as in securities fraud and major accident cases, including airplane crashes. While Alabama state courts do not directly handle MDLs, Alabama residents may be involved in MDL cases that are transferred to or from the state's federal district courts.