Which personnel security investigation standard is approved for Top Secret clearance eligibility for military positions?

The Single Scope Background Investigation (SSBI) is the standard approved for conducting personnel security investigations for Top Secret clearance eligibility in military positions. The SSBI is a comprehensive evaluation that covers various aspects of an individual's background, including their character, conduct, and associations, in order to assess their reliability and suitability for access to classified information.

This level of investigation is necessary for positions that require access to sensitive national security information, as it provides a thorough review of an individual's history and background over an extended period. This in-depth approach helps ensure that only individuals who meet stringent security standards are granted access to Top Secret information, thereby protecting national security interests.

Other options, while related to security clearances, do not meet the criteria for Top Secret eligibility. For instance, the Access National Agency Check with Inquiries (ANACI) is primarily used for Non-Sensitive and Secret clearance investigations but does not meet the complexity and depth required for Top Secret access. Similarly, Limited Access Authorization pertains to positions with less sensitive information, and a National Agency Check (NAC) is a more basic investigation that might be used for lower-level clearances but is not sufficient for Top Secret status.