Which entity provides guidance on personal identity verification for contractors?

The guidance on personal identity verification for contractors is primarily provided by the Office of Management and Budget (OMB). The OMB has established policies regarding the security clearance processes and the identification verification of individuals who are involved in federal contract work. These guidelines tie into the requirements for safeguarding sensitive government information and ensuring that contractors are properly vetted before gaining access to federal facilities or classified information.

The OMB's directives are crucial in establishing a consistent framework across federal agencies, thus enhancing security protocols related to contractor identification. While other agencies, such as the Department of Defense, General Services Administration, and regulations like the FAR, play significant roles in overarching procurement and operational policies, OMB has the specific responsibility for the guidance on personal identity verification. This makes it the correct choice in the context of this question.