independence requirements. Prior to 2015, DCAA also provided contract audit services to other government agencies, as well as other countries under the Foreign Military Sales (FMS) program, on a reimbursable basis. The largest non-DoD agency for which DCAA performed audits was NASAprimarily since the same government contractors do substantial business with both DoD and NASA, especially on major programs. However, Congress banned DCAA from performing non-Defense audits in the National Defense Authorization Act for Fiscal Year 2016. Agency structure DCAA's organizational structure consists of four Corporate Audit Directorates organized by major contractors, three geographical regions primarily focused on other large, mid-sized, and small contractors, and a Field Detachment focused on classified work. DCAA has about 300 offices located throughout the United States, Europe, and the Middle East. With the exception of Field Detachment and supervisory positions, DCAA employees are represented by American Federation of Government Employees Union (AFGE). Headquarters is at Fort Belvoir, Virginia. Principal elements are the Director, Deputy Director, General Counsel, Office of Inspector General, and the Assistant Directors for Operations, Policy and Plans, Integrity and Quality Assurance, and Human Capital and Resource Management. Regional Offices/Field Detachment are located in Smyrna, Georgia; Irving, Texas; La Palma, California; and Reston, Virginia. Each region directs and administers the DCAA audit mission at locations near the contractor base. Each region is staffed with 800 to 1000 employees and serves 2000 to 3000 contractors. The Field Detachment has 400 employees to serve 750 contractors. Corporate Audit Directorates (CAD) are located in Lowell, Massachusetts (Raytheon, General Dynamics, BAE); McLean, Virginia (Northrop Grumman); Hazelwood, Missouri (Boeing, Honeywell); and Fort Worth, Texas (Lockheed Martin). Each CAD directs and administers the DCAA mission at its major defense contractors. Branch Offices are strategically situated within the regions and are responsible for the majority of contract audit services within their assigned geographical areas. Branch offices often have smaller suboffices to ensure adequate audit coverage. Resident offices are established at specific contractor locations of both regions and CADs where the audit workload justifies the assignment of a permanent staff of auditors and support staff. These offices allow auditors to work on location with the largest major industrial manufacturers that the government buys from, such as Lockheed Martin, DynCorp, and General Dynamics. DCAA liaison activities are conducted at DoD acquisition or contract administration offices to directly communicate and coordinate audit processes. The DCAA also operates the Defense Contract Audit Institute