The Michigan Film Office (via Coming Soon) confirmed a state film incentive of $20 million (£13.2 million), and included plot details in a press release.
"As humanity picks up the pieces following the conclusion of Transformers: Dark of the Moon, Autobots and Decepticons have all but vanished from the face of the planet," the synopsis states.
"However, a group of powerful, ingenious businessman and scientists attempt to learn from past Transformer incursions and push the boundaries of technology beyond what they can control – all while an ancient, powerful Transformer menace sets Earth in his crosshairs.
"The epic adventure and battle between good and evil, freedom and enslavement ensues."
Michael Bay's first Transformers movie was filmed in Detroit, as was Transformers: Dark of the Moon.
Transformers 4, which stars Mark Wahlberg, is expected to arrive in Us and UK cinemas on June 27, 2014.