It requires notification to the United States Congress if the cost per unit goes more than 25% beyond what was originally estimated and calls for the termination of programs with total cost growth greater than 50%, unless the Secretary of Defense submits a detailed explanation certifying:
the program is essential to national security, that no suitable alternative of lesser cost is available;
new estimates of total program costs are reasonable; and
management structure is (or has been made) adequate to control costs.
Congress normally regards the explanations from the Secretary of Defense as acceptable. It is unusual for a program to be cancelled as a result of notification, but it has led to many changes to project management.
In 2006, the House of Representatives proposed amending the provision to require a detailed explanation, including information about possible alternatives, at the 15%-cost-growth mark.[citation needed]
The US Navy's Zumwalt-class destroyer's production cost increased from a projected $3.15 billion to $5.82 billion per ship, triggering a Nunn–McCurdy Amendment breach and cancellation of further production in 2016.[6]