Types of Security Clearances
This clearance provides access to information or material that may cause "serious damage" to national security if it were released without authorization.
For example: This information could refer to plans to conduct a tactical combat operation. The plans might cover only a single operation in a limited area for a very limited period of time. However, premature disclosure of this information could hurt the success of the operation.
To obtain a Secret Clearance, an individual must pass a "National Agency Check with Local Agency Checks and Credit Check" (NACLC), which looks back at the last five years of your life. A Secret Clearance must be renewed every 10 years.
Top Secret Clearance
This type of security clearance provides access to information or material that may cause "exceptionally grave damage" to national security if it was released without authorization.
For example: Unauthorized release of top secret information could include compromising vital national defense plans, complex cryptology and communications intelligence systems; revealing sensitive intelligence operations; and disclosing scientific or technological developments vital to national security.
Those who obtain a Top Secret Clearance have duties that demand the highest degree of public trust.
An investigation for a Top Secret Clearance is more thorough and reviews the last seven to 10 years of your life. The Top Secret Clearance requires a Single Scope Background Information (SSBI), which involves interviews with friends and family. The Top Secret Clearance must be renewed every five years.
Top Secret/Sensitive Compartmented Information (SCI)
Top Secret/Sensitive Compartmented Information (SCI) clearance is a distinction given to individuals who need access to highly sensitive information that could cause "grave damage" and/or compromise technologies, plans or procedures vital to national security if released without authorization.
For example: An NSA or CIA program.
A Top Secret/SCI clearance requires the same investigation process as a Top Secret Clearance, requiring a Single Scope Background Information (SSBI) that looks back at your last seven to 10 years. Top Secret/SCI must be renewed every five years.