Since mid-2015, President Barack Obama has tweeted under the handle @POTUS. On Monday, it was revealed that when the new president is elected on November 8, 2016, they will get access to the account on January 20, 2017, the day they are inaugurated. The follower count on @POTUS will remain the same, but the timeline of tweets will be wiped clean. Obama's tweets from @POTUS will be be archived on a newly-created account @POTUS44.
Other Twitter handles used by the Obama White House (@FLOTUS, @VP, etc.) will receive similar treatment, and their tweets will be preserved as well before being transitioned to the newly-elected president's cabinet.