By President Bush’s Executive Order, federal contractors must agree to use the Dept. of Homeland Security’s E-Verify system to verify the employment eligibility of their U.S. workers and those assigned to work on the federal contract in the U.S.

"Contractors that adopt rigorous employment eligibility confirmation policies are much less likely to face immigration enforcement actions, because they are less likely to employ unauthorized workers, and they are therefore generally more efficient and dependable procurement sources than contractors that do not employ the best available measures to verify the work eligibility of their workforce. It is the policy of the executive branch to use an electronic employment verification system because, among other reasons, it provides the best available means to confirm the identity and work eligibility of all employees that join the Federal workforce. Private employers that choose to contract with the Federal Government should meet the same standard,” says the Order.