Ingalls recently delivered the sixth NCS, Munro, and has two more under construction. Kimball (WMSL 756) is scheduled to be delivered in 2018 and Midgett (WMSL 757) in 2019.
It was announced a year ago that Ingalls would be getting the $640 million total contract.
NSCs are the flagships of the Coast Guard's cutter fleet, designed to replace the 12 Hamilton-class high-endurance cutters. Those ship entered service more than 50 years ago during the 1960s.
"As we continue to be the sole builder in this class, the benefits of serial production are apparent," said Derek Murphy, Ingalls' NSC program manager, "technologically advanced, dependable ships that are built at cost and on schedule."
Legend-Class National Security Cutters are the most technologically advanced ships in the Coast Guard fleet, with capabilities for maritime homeland security, law enforcement and national security missions. They have a top speed of 28 knots, a range of 12,000 miles, an endurance of 60 days and a crew of 120.
The award of the NCS follows a $1.46 billion contract announced in December to build the amphibious transport dock Fort Lauderdale (LPD 28) for the U.S. Navy.