A Single Scope Background Investigation is a type of security clearance investigation in the U.S. that is required for Top Secret, Sensitive Compartmented Information, and Q access. It is also known as SSBI. Such investigation includes field interviews of references. Coworkers, employers, personal friends, educators, neighbors and other appropriate individuals of the candidate may be interviewed. An SSBI may also include the candidate’s background checks, and checks of records held by employers, courts, and rental offices.
Additionally, the investigation may include a National Agency Check with Local Agency Check and Credit Check on the candidate’s spouse or cohabitant and any immediate family members who are U.S. citizens other than by birth or who are not U.S. citizens.