In order to be considered for Sensitive Compartmented Information (SCI) eligibility, an applicant must first be nominated for an SCI billet, complete a Single Scope Background Investigation (SSBI), and be approved by the government agency that controls the information. Since SCI encompasses several categories of compartmentalized information, Central Adjudication Facilities (CAFs) grant eligibility for access to SCI, and once this eligibility has been established, a person can be granted a special access authorization for a specific category of information within SCI. SCI access eligibility is divided into 3 sensitivity levels and each has a different investigative requirement:  SSBI w/o polygraph (poly); SSBI w/ CI Scope poly; and, SSBI full scope poly.