When Donald Trump moves in to the White House, it isn't just Barack Obama who will be moving on.
So will all the key members of his team.
They'll all be replaced by Republicans loyal to the new President, and many of Donald Trump's Cabinet nominees are still going through the confirmation hearings on Capitol Hill that are required before they're permitted to join the Trump team.
So who are the men and women expected to flank Donald Trump at Cabinet meetings and in the White House Situation Room?
Our Washington Correspondent Simon Marks reports.
IN: "Donald Trump….."
OUT: SOC
DUR: 3:36
AIR: http://www.fsnradionews.com/feeds/0118cabinet-sm-air.mp3
ARN: http://www.fsnradionews.com/feeds/0118cabinet-sm-arn.mp3
938 LIVE: http://www.fsnradionews.com/feeds/0118cabinet-sm-938.mp3
FM4: http://www.fsnradionews.com/feeds/0118cabinet-sm-fm4.mp3
ICRT: http://www.fsnradionews.com/feeds/0118cabinet-sm-icrt.mp3
NIGERIA: http://www.fsnradionews.com/feeds/0118cabinet-sm-von.mp3
RNZ: http://www.fsnradionews.com/feeds/0118cabinet-sm-rnz.mp3
VATICAN: http://www.fsnradionews.com/feeds/0118cabinet-sm-vat.mp3
ZIZ: http://www.fsnradionews.com/feeds/0118cabinet-sm-ziz.mp3
GENERIC: http://www.fsnradionews.com/feeds/0118cabinet-sm-generic.mp3
Donald Trump is such a big, brash, talker…..
AXX
….that it's sometimes easy to forget that his will not be a one-man government.
Far from it….there are at least four thousand positions that he needs to fill because so many jobs that in other countries would be part of the permanent civil service are instead politically appointed here….and change with every President.
The most significant, of course, are his top Cabinet positions and most of his nominees for those jobs are already explaining their views - and sometimes defending them - in a series of confirmation hearings taking place in the US Senate.
AXX - TILLERSON
That's Rex Tillerson, the former CEO of Exxon Mobil who is - if he wins Senate approval - about to replace John Kerry as Secretary of State.
Listen to what he had to say last week about Russia: it was notably much more hawkish than the admiration of Vladimir Putin often expressed by Donald Trump.
AXX
And Mr Tillerson is not be the only one who is promising to adopt a "clear-eyed" view on Russia.
Mike Pompeo is Mr. Trump's choice to head the CIA.
AXX
What about NATO?
Donald Trump has called it "obsolete".
That doesn't seem to be the view of the man he's chosen to be his Defence Secretary, the so-called "Mad Dog" General James Mattis.
AXX
On areas of domestic policy, other disagreements are evident between Mr. Trump and his team over issues including his plan to close America's borders to Muslims.
And it's far from evident whether Mr. Trump is as conservative on social policy as - for instance - Betsy de Vos, the woman he's chosen to head the Department of Education….or Dr. Ben Carson, about to head the Department of Housing and Urban Development.
Long-time observers of life in Washington, like analyst Bonnie Glaser from the Center for Strategic and International Studies, say many of the President's choices have as little experience in government as he does.
AXX
But that doesn't trouble Trump fans who say Washington could use some fresh blood, fresh ideas and fresh approaches.
Republican Party official Matthew Hurt.
AXX
The men and women joining Donald Trump's Cabinet are themselves in for an interesting ride.
The President-elect's propensity to sound off on Twitter about a variety of topics anytime day or night means they could constantly find themselves explaining what he's just said.
But they can take comfort in one recent Tweet: Mr. Trump said of his Cabinet choices "I want them to be themselves and express their thoughts, not mine".
SOC