A total of 2,550 radios will be produced under the award which is worth $24 million.
Units under the new award will be delivered this year and in 2016, Boeing said.
"CSEL radios have proven themselves to be instrumental in helping locate isolated personnel and getting them out of danger," said Steve Capps, Boeing CSEL program manager. "Wherever they fight, our forces can depend on CSEL for secure satellite communications, line-of-sight voice connectivity, global position and navigation information, and beacon functions."
Boeing has produced about 55,000 of the hand-held radios to date, as well as over-the-horizon relays and related user equipment.
Additional contracts have also been given the company to enhance the capabilities and information security of the global CSEL base-station network, it said, but no additional details were provided.