The contract covers the first lot of 36 ACVs, an eight-wheeled, ship-to-shore landing craft, with 36 more to be built in 2021, and an option for 80 vehicles per year for five years.
The Marines announced the vehicle's Initial Operational Capability in November, indicating that full production can begin.
The vehicles will "replace the 40-year-old Amphibious Assault Vehicle, or AAV, which currently transports Marines from ships to shore under hostile conditions" but has only a two-mile ship-to-shore range, a July report to Congress said.
A prior attempt to design a suitable vehicle, known as the Expeditionary Fighting Vehicle, was cancelled in 2018 because of expected cost overruns.
BAE Systems began building the first ACVs in 2018, and the contract, announced on Thursday, assures a steady production run.
Each vehicle is armed with a 30mm medium caliber cannon and other weapons, and can carry up to 13 personnel, or an entire rifle squad. Its V-shaped hull, and seating suspended over the hull, provides protection from underbody explosions
"The ACV is a highly mobile, survivable, and adaptable platform for conducting full spectrum ship-to-shore operations and brings enhanced combat power to the battlefield," the company said on Thursday in a press release.
"With a force protection capability three times greater than the Assault Amphibious Vehicle, the ACV is designed so Marines can complete their missions successfully," BAE said.