On September 16, 2011, the America Invents Act (AIA) ushered in major changes to the U.S. patent system, including changes affecting assertion of patent infringement against multiple, unrelated accused infringers. Effective upon enactment, the AIA added 35 U.S.C. § 299 to limit joinder of accused infringers in district court actions.

Now, accused infringers may only be joined in one action as defendants or counterclaim defendants, or be consolidated for trial, by meeting the following statutory requirements:

(1) that the right to relief asserted against the parties jointly, severally, or in the alternative, is with respect to or arises out of the same transaction or occurrence relating to infringement of the same accused product or process, and

(2) that questions of fact common to all defendants or counterclaim defendants will arise.