 Holt announced on February 18, 2014 that he would not seek re-election in 2014.In February 2015, Holt became chief executive officer of the American Association for the Advancement of Science (AAAS) and executive publisher of the "Science" family of journals.In July 2019, AAAS announced that Holt was taking immediate leave and would retire effective 1 September 2019.