Prosecutors have said that the Havard bomb scare was ignited by a student who was trying to avoid writing his finals.
Four campus buildings were evacuated after Eldo Kim allegedly sent hoax emails saying bombs were at the sites in Cambridge, Massachusetts.
The buildings were shut down for several hours on Monday morning while searches were carried out before investigators deemed there were no explosives.
The messages were sent to Harvard police, two university officials and the president of the Harvard Crimson newspaper.
Kim, 20, allegedly told an agent he had acted alone and posted messages to five or six Harvard email addresses he picked at random.
The emails said shrapnel bombs would go off in two of the four buildings, including one where Kim was supposed to take an exam at 9am on Monday, prosecutors said.
Kim’s profile on the social networking site LinkedIn says he is an undergraduate scholar at Harvard’s Institute for Quantitative Social Sciences.
The suspect, who lives in Cambridge, has been charged over the threats and is set to make his first court appearance later.
The maximum penalties for a bomb hoax are five years in prison and a $250,000 (£153,000) fine, prosecutors said.
Classes are held at three of the four sites while the fourth is a freshman dormitory.
Harvard said it was “saddened” by the allegations but would have no further comment on the investigation.