Before March 16, 2013, patents were awarded to the first inventor of a product or process. This first-to-invent system allowed a party to challenge the inventorship on a pending application or issued patent through an interference proceeding. The question of priority is determined by a board of administrative patent judges on which party first invented the commonly claimed invention.

Since the America Invents Act (AIA) was signed into law, derivation proceedings have replaced interference proceedings. The AIA changed the U.S. patent system from a first-to-invent system to a first-to-file system, which came into effective on March 16, 2013.

A party who is not the first to file a patent application may file a derivation petition to challenge an earlier applicant’s right to a patent if they can show the invention was derived from an inventor in the petitioner’s own application.  Derivation proceedings often result from prior business relationships, for example vendor-vendee, joint ventures, or former employees.