# National Security Population
**Entity class:** Personnel-vetting population measure
## Definition
The **national-security population** is GAO's term for federal personnel, service members, and contractors eligible for access to classified information or to occupy a sensitive position. GAO estimated approximately 5.4 million people as of October 1, 2022, including roughly 5 million associated with the Department of Defense.
The measure is a personnel-vetting universe. It is not a count of intelligence officers, agents, informants, or people actively performing counterterrorism work. GAO also found significant data-reliability limitations affecting oversight.
## Relationships
- **oversight:** [[wiki/Government Accountability Office|GAO]].
- **largest component:** [[wiki/United States Department of Defense|Department of Defense]].
- **counting boundary:** [[wiki/Intelligence Participation Headcount|Intelligence Participation Headcount]].
- **distinct from:** [[wiki/United States Intelligence Community|Intelligence Community]] workforce.
## Sources / Provenance
- [GAO — Personnel Security Clearances, August 2026](https://files.gao.gov/reports/GAO-26-107100/index.html)