The Nunn–McCurdy Amendment or Nunn–McCurdy Provision, introduced by Senator Sam Nunn and Congressman Dave McCurdy in the United States 1982 Defense Authorization Act and made permanent in 1983, is designed to curtail cost growth in American weapons procurement programs.
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.
Very rarely is a program actually cancelled under this provision—Congress normally regards the explanations from the Secretary of Defense as acceptable—but it has led to many changes to project management. SBIRS has been affected by the provision in 2002 and again in 2005.  However, in 2009 and 2011 the US Army's FCS and USMC EFV vehicle programs were both cancelled due to cost overruns.
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.
- 109th Congress, 2nd Session, House of Representatives. Hearing before the Committee on Science, The future of NPOESS: results of the Nunn-McCurdy review of NOAA's weather satellite program. June 8, 2006. Serial No. 109-53. Government Printing Office, Washington, D.C., 2007
- House Report 109-748 - Summary of activities of the Committee on Science U.S. House of Representatives for the One Hundred Ninth Congress, p.119. January 4, 2007. Government Printing Office, Washington, D.C., 2007
- "NPOESS/Nunn-McCurdy Findings Leave Unanswered Questions on the State of U.S. Weather Forecasting Satellites". SpaceRef. 8 June 2006. Retrieved 14 November 2013.
- Office of the Assistant Secretary of Defense (Public Affairs) (23 June 2009), "Future Combat System (FCS) Program Transitions to Army Brigade Combat Team Modernization", United States Department of Defense, retrieved 13 November 2013
- Office of the Assistant Secretary of Defense (Public Affairs) (6 January 2011), "Statement by the Commandant of the Marine Corps Gen. James Amos on Efficiencies", United States Department of Defense, retrieved 13 November 2013