BBC: 'In Tehran on Monday, judiciary spokesman Gholam Hossein Mohseni Ejehi said a court had summoned Ms Shourd to return and stand trial on 6 February.
Iran has said she will forfeit $500,000 (£314,386) bail if she does not return to stand trial. It remains unclear who provided the money.
It was unclear on Monday whether Ms Shourd would agree to return.
The US has said there is no basis for a trial and has demanded that Mr Bauer and Mr Fattal be released on humanitarian grounds.
The trial had been set to begin in November but was postponed because Ms Shourd had not been summoned back.
Meanwhile, on Monday a group of eight international figures, including Noam Chomsky, actor Sean Penn and South African anti-apartheid leader Archbishop Desmond Tutu, called for Iran to release the two men.
"The time for Shane and Josh's freedom is overdue and we implore you to allow them to go free and return to their families," the group said in a statement. '