Under a plea deal, Masri has agreed to serve just under 10 years in prison.
He admitted to plotting to raise the funds he needed to engage in jihad in either Somalia or Afghanistan.
He had faced a maximum of 15 years in prison.
Masri was born in Alabama and lived in Chicago prior to his arrest just hours before leaving the country.
He had been confiding in an undercover FBI agent and had talked about targeting "infidels".
Following his arrest he was charged with attempting to provide material support to a terrorist group, and trying to offer material support by use of a weapon of mass destruction.
The full details of the plea bargain have not been made public.
Dozens of US citizens have been arrested in recent years for trying to participate in or support the two-decade long civil war.