Professionally, Duncan was President of the Kentucky Bankers Association and a Director of the Cleveland Federal Reserve Bank Cincinnati Branch. In 1989-91, during a sabbatical, he worked in the Bush White House as Assistant Director of Public Liaison. His public service has been recognized with several distinctions including honorary degrees from Cumberland College and the College of the Ozarks.
He has served as General Counsel of the Republican National Committee (RNC) since July 10, 2002. He previously was elected Treasurer of the RNC in January 2001. Duncan, in his third term as National Committeeman from Kentucky, has served the party at every level from precinct captain, county chairman, state chairman, and national officer. He has been a delegate to the 1972, 1976, 1992, 1996, and 2000 Republican National Conventions and is one of the few persons ever to serve on the four standing convention committees. Mike Duncan and his wife Joanne are 1974 graduates of the University of Kentucky College of Law. Duncan received his undergraduate degree from Cumberland College. They live in Inez, Kentucky, and have one child, Rob, a recent University of Kentucky College of Law graduate. The Duncans are the principal owners of two community banks with five offices in eastern Kentucky.