Security clearances allow personnel access to classified information that, through unauthorised disclosure, can, in some cases, cause exceptionally grave damage to U.S. national security. To safeguard classified data and manage costs, agencies need an effective process to determine whether civilian positions require a clearance. This book discusses agencies needing clearly defined policies for determining civilian position requirements; answers frequently asked questions on the security clearance process; and provides statements and testimonies from a hearing on the insider threat to homeland security.