ⓘ List of U.S. security clearance terms


ⓘ List of U.S. security clearance terms

Security clearance levels are used as part of a method to control access to information that should not be freely available to all personnel.

The different organizations in the United States Federal Government use different terminology and lettering, as is discussed below.


1. Use

Security clearance levels often appear in employment postings for Defense related jobs, and other jobs involving substantial amounts of responsibility, such as air traffic control or nuclear energy positions. Employers generally prefer to hire people who are already cleared to access classified information at the level needed for a given job or contract, because security clearances can take up to a year to obtain. In general, most employers look for candidates who hold an active Department of Defense DoD collateral clearance or a blanket TS/SCI-cleared Top Secret / Sensitive Compartmented Information individual who has a counterintelligence CI, full-scope polygraph FSP, also known as expanded scope screening ESS.


2. Security levels

Security clearances can be issued by many United States of America government agencies, including the Department of Defense DoD, the Department of State DOS, the Department of Homeland Security DHS, the Department of Energy DoE, the Department of Justice DoJ, the National Security Agency NSA, and the Central Intelligence Agency CIA. DoD issues more than 80% of all clearances. There are three levels of DoD security clearances:

  • TOP SECRET – Will be applied to information in which the unauthorized disclosure could reasonably be expected to cause exceptionally grave damage to the national security.
  • SECRET – Will be applied to information in which the unauthorized disclosure could reasonably be expected to cause serious damage to the national security.
  • CONFIDENTIAL – Will be applied to information in which the unauthorized disclosure could reasonably be expected to cause damage to the national security.

Additionally, the United States Department of Energy issues two levels of security clearances:

  • L Clearance – Allows access to Classified information up to and including SECRET data with the special designation: Formerly Restricted Data S//FRD and special L-Cleared "limited" areas.
  • Q Clearance – Allows access to Classified information up to and including TOP SECRET data with the special designation: Restricted Data TS//RD and special Q-Cleared "security" areas.

Despite the common misconception, a public trust position is not a security clearance, and is not the same as the confidential designation. Certain positions which require access to sensitive information, but not information which is classified, must obtain this designation through a background check. Public Trust Positions can either be moderate-risk or high-risk.

Information "above Top Secret" is either Sensitive Compartmented Information SCI or special access program SAP which are phrases used by media. It is not truly "above" Top Secret, since there is no clearance higher than Top Secret. SCI information may be either Secret or Top Secret, but in either case it has additional controls on dissemination beyond those associated with the classification level alone. In order to gain SCI Access, one would need to have a Single Scope Background Investigation SSBI. Compartments of information are identified by code words. This is one means by which the "need to know" principle is formally and automatically enforced.

In order to have access to material in a particular SCI "compartment", the person must first have the clearance level for the material. The SCI designation is an add-on, not a special clearance level. Someone cleared at the SECRET level for some compartment X cannot see material in compartment X that is classified TOP SECRET. But the reverse is not true: a person cleared for TOP SECRET with access to X material can also access SECRET material in compartment X. The codeword flags for SECRET and TOP SECRET material in every compartment are different, and each codeword is classified at the level it protects the SECRET codeword for a compartment is itself classified SECRET, etc.

As long as the holder of a clearance is sponsored, the clearance remains active. If the holder loses sponsorship, the holder is eligible for re-employment with the same clearance for up to 24 months without reinvestigation, after which an update investigation is required.

A Periodic Reinvestigation is typically required every five years for Top Secret and ten years for Secret/Confidential, depending upon the agency. Access to a compartment of information lasts only as long as the persons need to have access to a given category of information.

Unclassified U is a valid security description, especially when indicating unclassified information within a document classified at a higher level. For example, the title of a Secret report is often unclassified, and must be marked as such. Material that is classified as Unclassified // For Official Use Only U//FOUO is considered between Unclassified and Confidential and may deal with employee data.

For access to information at a given classification level, individuals must have been granted access by the sponsoring government organization at that or a higher classification level, and have a need to know the information. The government also supports access to SCI and SAPs in which access is determined by need-to-know. These accesses require increased investigative requirements before access is granted.


3. Investigations

The following investigations are used in clearance determinations:

  • PPR – Phased Periodic Reinvestigation
  • SSBI-PR – SSBI Periodic Reinvestigation
  • T3 or T3R - Tier 3 or Tier 3 Reinvestigation, now replace all NACLC.
  • Yankee White – An investigation required for personnel working with the President and Vice President of the United States. Obtaining such clearance requires, in part, an SSBI.
  • SSBI Single Scope Background Investigation – Initial Top Secret, SCI, Q, QX
  • MBI – Moderate Risk Background Investigation – NACLC plus a Personal Subject Interview PRSI and written inquiries to employers, schools, and references for past 5 years.
  • T5 and T5R - Tier 5 or Tier 5 Reinvestigation, now replace SSBI and SBPR respectively.
  • ANACI Advance National Agency Check with Inquiries – Initial Confidential, Secret, L, LX; only used for civilian employees
  • NACLC National Agency Check with Law and Credit – Initial Confidential, Secret, L, LX; reinvestigations
  • PRS – Periodic Reinvestigation-Secret

Many other investigative products have been used to grant clearances in the past. While some of them are still used to determine suitability for employment or enlistment, only the above are used to grant clearances.


4. Additional investigation or adjudication

Certain accesses require persons to undertake one or more polygraph tests:

  • Full Scope / Lifestyle FSP, FS, LS, Lifestyle Poly
  • Counterintelligence Scope CI, CI Poly

5. SCI eligibility

Sensitive compartmented information SCI is a type of classified information controlled through formal systems established by the Director of National Intelligence. To access SCI, one must first have a favorable SSBI and be granted SCI eligibility. Because the SSBI is also used to grant collateral top secret eligibility, two are often granted together and written TS/SCI. Access to individual SCI control systems, compartments, and subcompartments may then be granted by the owner of that information. Note that additional investigation or adjudication may be required.

In general, military personnel and civilian employees government and contractor do not publish the individual compartments for which they are cleared. While this information is not classified, specific compartment listings may reveal sensitive information when correlated with an individuals resume. Therefore, it is sufficient to declare that a candidate possesses a TS/SCI clearance with a polygraph.