The 60-year-old kingpin, accused of running one of the world's biggest drug empires and who twice escaped prison in Mexico, was originally expected to go on trial in April.
But on Wednesday, federal judge Brian Cogan ordered lawyers to clear their calendars for a September trial, saying summer vacation schedules could reduce the jury pool for an August date.
On Monday, Cogan had delayed the latest pre-trial hearing from January 19 to February 15, after Guzman's lawyer demanded more time to review several hundred thousand pages of documents in the case.
Guzman has been held in solitary confinement in New York since being extradited to the United States a year ago.
Accused of running the Sinaloa cartel, he is facing 17 charges, and if convicted, he is likely to spend the rest of his life in a maximum security US prison.
- Countries: Latin America