This letter responds to your request for information on cases pending and concluded in federal and state courts that invoked the Y2K Act (Public Law 106-37). The Y2K Act, signed into law on July 20, 1999, established certain procedural requirements for civil actions relating to an actual or potential year 2000 failure that could occur or has allegedly caused harm. The Y2K Act generally defined a year 2000 failure as a failure of any device or system to process or otherwise deal with the transition from the year 1999 to the year 2000. The Y2K Act's procedures included administrative dispute resolution provisions, prelitigation notification requirements, limitations on class actions, provisions giving federal district courts original jurisdiction over certain types of class action cases, and heightened pleading requirements. The Y2K Act applied retroactively to any case filed in federal or state court after January 1, 1999, for a potential or actual year 2000 failure occurring before January 1, 2003.