Mark David Uhl, 19, asked the court for leniency at Tuesday's sentencing, but that was rejected by U.S. District Judge Norman K. Moon.
"For the court to just let you walk out of here like this was some kind of Halloween prank would be criminal," Moon said.
Uhl was arrested May 21 after Campbell County authorities acting on a tip searched the trunk of his car and found five bombs that state police agents called "homemade napalm."
Authorities have said they do not believe Uhl intended to disrupt Falwell's funeral services or harm the Falwell family. At a hearing in May, a federal agent had said Uhl had other plans for violence, including a plot with a friend to disrupt a prom at his former high school in northern Virginia with pepper spray.
Uhl rriveracould have received up to 10 years in prison, but he had changed his plea to guilty under an agreement with prosecutors. The judge also ordered him to serve three years on probation following his release from prison.