Adam Edelen is resigning as Gov. Steve Beshear's chief of staff, to be replaced by Mike Haydon, the governor's chief legislative liaison.
Edelen, 35, took the post in July 2008 after serving six months as Beshear's homeland security director. His final day will be Sept. 15.
Edelen said he plans to work in Lexington as a business management consultant, steering clear of state government contractors to avoid possible conflicts of interest.
"I just think it's time," Edelen said. "As the governor moves into the fall and prepares for another legislative session, it's good for the purposes of continuity for him to have a new chief of staff in place."
Edelen would not address rumors that he hopes to run next year as a Democratic candidate for state auditor. The current auditor, Crit Luallen, is term-limited and cannot seek re-election.
"My life's passion is public service," Edelen said. "I'll have something more to say in the future about that passion."
Haydon, a former mayor of Springfield, has served in state and local government for several decades, including stints under Gov. Paul Patton as revenue secretary and deputy secretary of the governor's cabinet.
"Mike knows every corner of this state, and he has dedicated his life to public service," Beshear said. "He brings a breadth of knowledge and depth of understanding about this state's challenges that few can match, and I am confident in his ability to serve my office and the people of Kentucky in this critical position."