Mark Whitty Everson (born September 10, 1954) is an American politician who is currently the Vice Chairman of alliantgroup and served as the 46th Commissioner of Internal Revenue from 2003 until 2007. Prior to his appointment as Commissioner of the IRS, Everson held a number of federal government positions in the administrations of George W. Bush and Ronald Reagan, as well as at the state level within the administration of Indiana Governor Mitch Daniels. In August 2009, Everson joined alliantgroup, LP, a national tax advisory consultant, to advise the firm and its clients on matters related to the IRS and on strategic, operational, and client service initiatives. Everson was a candidate for the Republican presidential nomination in 2016, until he withdrew his candidacy on November 5, 2015.