United States Anti-Doping Agency Reauthorization Act - Amends the Office of National Drug Control Policy Reauthorization Act of 2006 to: (1) authorize appropriations for the U.S. Anti-Doping Agency for FY2014-FY2020, (2) require that the Agency be recognized worldwide as the independent national anti-doping organization for the United States, and (3) replace the Agency's role in preventing the use by U.S. amateur athletes of performance-enhancing genetic modifications accomplished through gene doping with a role in preventing the use of prohibited performance-enhancing methods adopted by the Agency.