Officials said 28-year-old Esteban Santiago of Anchorage, Alaska, will agree to a life sentence.
The announcement was made in Miami on Tuesday.
Santiago pleaded not guilty to a 22-count indictment in the January 2017 shooting in a baggage claim area at Fort Lauderdale-Hollywood International Airport. Authorities say he got a handgun from checked luggage, loaded it in a bathroom and came out firing.
Since his arrest, Santiago has been treated at a Miami jail for schizophrenia. He complained of mental problems before the shooting but was not barred from possessing a gun.