The National Inventors Hall of Fame (NIHF) is an American not-for-profit organization, founded in 1973, which recognizes individual engineers and inventors who hold a U.S. patent of significant technology. Besides the Hall of Fame, it also operates a museum in Alexandria, Virginia, sponsors educational programs, and a collegiate competition. As of 2020, 603 inventors have been inducted, mostly constituting historic persons from the past three centuries, but including about 100 living inductees. Nominees must hold a U.S. patent of significant contribution to the U.S. welfare, and which advances science and useful arts. The 2020 class included 22 inventors.