The UC Contractor Assurance System (CAS) for Berkeley Lab is a system of processes and tools designed to provide assurance that the Laboratory’s mission objectives are achieved; its workers, the public, and the environment are protected; its operational, facility and business systems are effectively managed; and the requirements of the UC/DOE contract are met. The CAS description has been developed jointly between the UC Office of the National Laboratories (UCNL) and Berkeley Lab. The DOE Berkeley Site Office (BSO) is provided timely notification of significant changes to the assurance system prior to implementation.