The Americans, who were not identified, left the country together with Yemenis hurt in a recent funeral bombing, US Secretary of State John Kerry said.
The US thanked Oman for mediating and acknowledged the "humanitarian gesture" from the rebels.
Yemen has been devastated by a war between government forces and those allied to the Houthi rebel movement.
More than 6,800 people have been killed since March 2015, the majority in air strikes by a Saudi-led multinational coalition that backs the president against the Houthi rebels.
