The U.S. Government conducts background investigations and reinvestigations to establish that military personnel, applicants for or incumbents in national security positions, either employed by the Government or working for Government contractors, licensees, certificate holders, and grantees, are eligible for a required security clearance. Information from this form is used primarily as the basis for investigation for access to classified information or special nuclear information or material. Complete this form only after a conditional offer of employment has been made for a position requiring a security clearance.