E-Verify is a program administered by the Department of Homeland Security’s (DHS) Citizenship and Immigration Services (USCIS) bureau, in partnership with the Social Security Administration. This is a web-based program that allows employers to verify that their employees are authorized to work in the United States.
E-Verify is required for all federal contractors. For documentation explaining this rule can be found here.
Several states, such as Nebraska, also require all state contractors and state / public organizations to participate in E-Verify.