Babar Ahmad and Syed Talha Ahsan were extradited from Britain last year. They are accused of operating websites to raise cash, recruit fighters and solicit items such as gas masks.
Court records show they have hearings scheduled today in New Haven to change their pleas on charges of providing support to terrorists. They had previously pleaded not guilty.
Their attorneys did not return telephone and email messages seeking comment.
If convicted, Ahsan faces up to 15 years in prison and Ahmad faces up to 30 years.