Ambinder received a A.B. from Harvard University in 2001.
Ambinder is a Leadership Fellow at the University of Southern California's Annenberg School of Communications and Journalism, and he consults for Fortune 100 companies on corporate and strategic communication.
Until December 31, 2011 Ambinder was the White House correspondent at the National Journal. He previously worked at ABC News and was chief political consultant to CBS News from 2008 to 2011. For years, he was the author of an influential political blog, The Hotline.
Though presidential politics and Washington have been his primary beats, he also writes about intelligence and national security, and has broken several stories, including details about the raid on Osama bin Laden. His first book, "The Command: Inside The President's Secret Army," is an examination of the secretive Joint Special Operations Command.
He secured access to the protective details of the Secret Service, broke stories about dangerous computer failures that jeopardized America’s nuclear arsenal, probed Pakistan’s fragile intelligence services, and became an authority on national security topics ranging from the NSA and surveillance to the government’s secret commando force to its secretive continuity of government plans. 
He has written for The New York Times, The New Yorker, The Washington Post, Vice, and numerous national magazines. He has been a consulting producer and on-air expert for documentaries about special operations forces, the Secret Service and government doomsday plans. He has been a guest on every national television news network in the U.S., on the BBC, on Al Jazeera International and was a regular analyst on politics for CBS News Radio.
His online journalism has won him several awards and attracted a large Twitter following. He was nominated for an Emmy in 2005 and was part of a team that won a DuPont Silver Baton from Columbia University. 
Gawker reported that, in 2009, Ambinder struck a deal with Hillary Clinton spokesman Philippe Reines to provide positive remarks on Clinton in exchange for receiving an advance copy of a Clinton speech. Gawker based its report on a fragment of an email chain they obtained through a Freedom of Information Act request. Both Ambinder and Reines said that the emails lacked critical context, which showed that Ambinder did not actually make any such deal with Reines. Ambinder later said he regretted how such incidents, even when misinterpreted, contributed to the fraying of trust between political journalists and the public, and decried the proliferation of transactional reporting in Washington.