The department said in a memo it was adding CNN, the Washington Post, the Hill and the War Zone to the outlets that must give up their dedicated space. Those organizations did not immediately respond to requests for comment.
In the first round, the Defense Department said a week ago the New York Times, NBC News, Politico and the National Public Radio had to vacate their dedicated workspaces at the Pentagon.
Incoming media outlets include the New York Post, Breitbart, the Washington Examiner, the Free Press, the Daily Caller, Newsmax, the Huffington Post and One America News Network, most of whom are seen as conservative or favoring Republican President Donald Trump, who took office on January 20.
Outgoing outlets will remain members of the Pentagon Press Corps, the memo said, adding that the rotation expressed a desire to make room for other media outlets.
More than two dozen news organizations operate out of the Pentagon, including Reuters, reporting on the daily activities of the US military.
The Pentagon Press Association, which represents journalists who cover the Defense Department, said it was "shocked and deeply disappointed by the Defense Department's decision to double the number of news organizations it is removing in two weeks from their dedicated workspaces in the Pentagon from four to eight."
Reuters correspondent Phil Stewart is a member of the association's four-member board of directors.