Phillip D. Brady, general counsel to the Transportation Department, will move to the White House after the first of the year to become an assistant to the president and staff secretary.
The person in that post manages the paperwork into and out of the Oval Office.
Brady, 39, will replace James Cicconi, who is leaving to return to his former law firm.
Although the job gets little public notice, it has been a pivotal one in many administrations because its occupant sits at the center of many of the administration debates.
The staff secretary has access to the options papers, memos and draft statements that frame the issues on which the president makes decisions.
The post was its most powerful when it was held by Richard G. Darman in the first-term Reagan White House, where it became Darman's platform for close involvement in a range of domestic issues and politics.
Brady, a Californian, came to Washington as a legislative counsel to then-Rep. Daniel E. Lungren in 1981 and worked in ACTION, the volunteer service agency, the Immigration and Naturalization Service and in the Justice Department's office of legislative and intergovernment affairs.
He worked in the vice president's office when Bush was involved in the drug task force, and shifted over to the White House briefly in 1988, where he was involved in some of the transition rules and paperwork preparing for the new administration.