From Wiki,Upon becoming the presumptive Republican presidential nominee, Trump announced that he would nominate Icahn for United States Secretary of the Treasury.[95] However, he instead nominated Steven Mnuchin.[96][97]

On December 21, 2016, it was announced that Icahn would serve as special advisor to the president on regulatory reform under President Donald Trump and that Icahn would aid Trump in an "individual capacity" rather than as a federal employee, and that he would not have "specific duties" and therefore would not have to relinquish his business interests while serving as an advisor to Trump.[98] Icahn stepped down from this role on August 18, 2017, citing a desire not to interfere with the work of Neomi Rao as administrator of the Office of Information and Regulatory Affairs.