From the Congressional Research Service June, 28 2013 report on development of the Marine Corps next-generation amphibious assault vehicle:

A Feb. 01, 2007 test of the Expeditionary Fighting Vehicle (EFV) in Alaska. US Marine Corps Photo

On January 6, 2011, after spending approximately $3 billion in developmental funding, the Marine Corps cancelled the Expeditionary Fighting Vehicle (EFV) program due to poor reliability demonstrated during operational testing and excessive cost growth. Because the EFV was intended to replace the 40-year-old Amphibious Assault Vehicle (AAV), the Pentagon pledged to move quickly to develop a “more affordable and sustainable” vehicle to replace the EFV. The Amphibious Combat Vehicle (ACV) is intended to replace the AAV, incorporating some EFV capabilities but in a more practical and cost-efficient manner. Read More →