The three levels of security clearance

Security clearance levels and their descriptions

Security clearances can be issued by many United States government agencies, including the Department of Defense (DoD), the Department of Homeland Security, the Department of Energy (DoE), the Department of Justice, and the Central Intelligence Agency. DoE clearances include the “L”, and “Q” levels. DoD issues more than 80% of all clearances.

The DoD and most other agencies have three levels of security clearances:


Obtaining a confidential security clearance requires between a few weeks to a few months. The process is largely administrative, but financial issues or security concerns may delay the process. The questionnaire dates back seven years on the applicant’s record.


A Secret clearance takes a few months to a year to adjudicate. The majority of Secret security clearance investigations are based almost entirely on automated records checks. Only around 25 percent of Secret clearance applications require additional field work by a background investigator, to investigate issues from prior drug use to financial problems. Even those issues may be mitigated if answered honestly, and if sufficient time has passed between any incidents and the application.


Top Secret clearance requires a Single Scope Background Investigation and grants access to data that affects national security, counterterrorism, counterintelligence or other highly sensitive data. A Top Secret clearance can take between six and 18 months to adjudicate.