Military security clearances (as well as their civilian counterparts) require a lengthy process of interviewing, researching, and background investigation. This process is a requirement in order to be approved for a Confidential, Secret, or Top Secret clearance.
It would be easy to assume that this is the first and last word on who is permitted to access controlled information, data, hardware, or facilities, but it is not.
In addition to clearance procedures to handle, access, or otherwise access Confidential, Secret, or Top Secret classified things there are also checks done for those who are required to access Sensitive Compartmented Information, or SCI.
These checks are part of the Single Scope Background Investigation, or SSBI. This type of investigation, as you might guess, is not done for all security clearances–only those that require access to SCI.
What Is SSBI?
Single Scope Background Investigations (sometimes referred to as Tier 5 depending on the context and application of the investigation) are required for access to SCI. This investigation does NOT confer an additional security clearance on the applicant; instead it is used to support Top Secret clearances and provides access to SCI upon successful completion of the investigation.
Those who have Top Secret clearances are not automatically granted access to SCI.
Only those with a specific need to access it are eligible to be investigated and cleared to do so. When such access is awarded the classification may be referred to as Top Secret/SCI but there is no “fourth clearance” here–just an additional designation for access to SCI.
Some confuse SSBI with SCI. The easy way to remember them properly is to keep in mind that Single Scope Background Investigations are the process used to clear the applicant for access to Sensitive Compartmented Information.

What To Expect From A Single Scope Background Investigation
Those who are familiar with security clearance procedures already know that the vetting process can take a long time–and go back in personal history for a long time, too.
You can expect to have the last decade of your life reviewed for “general information” about your professional work, your education, even your finances and associations. You can expect scrutiny over your personal information and relationships for roughly seven years.
Your background investigator will, in the course of determining if you are to be a successful applicant for a Top Secret Clearance as well as SCI access, examine many of the following areas of your life, and more:
- Date and location of your birth
- Citizenship verification
- Credit checks for information including financial issues, past residences, patterns of spending or debt, etc.
- A database check of local-to-the-applicant law enforcement records
- A database check of national agencies including the FBI for derogatory information about the applicant
- A check of your spouse, partner, or roommates “to determine allegiance, associations and other factors”
- A review of any other public records that may show activities, proclivities, etc.
- Review of schools and employers the applicant has associated with
- Interviews with applicant-provided references
Even the most basic security clearance background checks cover a wide range of personal details. Consider what is required on Standard Form 86, Questionnaire for a National Security Position–the applicant must list information about all of the following (and more), to the best of their recollection:
- Foreign contacts, activities, travel
- Other names or aliases
- Psychological and emotional health
- Police Record
- Illegal use of drugs and drug activity
- Use of alcohol
- Investigation and clearance record
- Selective Service Record
- Financial record
- Military history
- Use of information technology systems
- Involvement in Non-Criminal court actions
- Relatives
Who Is Subject To An SSBI
The first thing to remember is that the employee or military member cannot initiate a background check or security clearance procedure–this will be done through your supervisor, command support staff, etc.
The applicant is required to comply with the investigation as a condition of employment or enlistment. Failure to cooperate with the investigation may not lead immediately to job loss, but the inability to get or maintain a security clearance is a major problem for government service of any kind.
Those who need an SSBI are often informed by their supervisors that the need exists; this may be thanks to a job transfer or permanent change of station move to a new assignment that requires the access. It may also be associated with military promotions, changes in staffing or mission requirements, and many other reasons.
As mentioned above, if you possess a Top Secret clearance, you don’t automatically gain access to SCI–you must be vetted for this access.
Some find that promotions or PCS moves bring with them a change in requirements, such as the newly promoted Army Staff Sergeant who is reassigned to a sensitive area. This person may have carried a lower clearance before the reassignment but now has to go through the vetting process for the higher clearance.
While SSBI and SCI are often associated with military intelligence matters, many federal agencies including those in a non-military capacity (such as the Department of Energy) also have requirements for security clearances and levels of clearance. As a military member you might not expect certain federal jobs to carry the same or similar levels of rigor with respect to background checks, but they do.
A Word About Polygraph Examinations
Some mistakenly believe that polygraphs or lie detector tests are required for SCI access. This is not true in all cases; not everyone being vetted for certain types of access will experience a polygraph test. But some will be administered this test and you should not be surprised if you are expected to submit to one as a condition of clearance access.
Reinvestigations
The Top Secret/SCI classification is not permanent, nor is it indefinite. The intelligence community and background investigation field are both moving toward a philosophy and practice of “continuous vetting”, but even this does not prevent a security clearance holder from needing to be reinvestigated after a period of time defined by the federal government.
Reinvestigations are also common if there is a lapse in holding a clearance, if there was a dispute about the eligibility of the clearance holder, or their suitability to continue holding the clearance.
Time Investment In The Background Check Process
Getting cleared for Top Secret access that includes SCI is very time consuming but one way to speed up the process is to give the most accurate and complete information you can. Some people think that strategic omission of certain facts, incidents, associations, or other potentially negative information will be missed by the investigators.
But remember that investigators often have years of training and experience and recognize the patterns that show up when the applicant has omitted information that should have been shared with investigators.
Background checks are incredibly detailed and thorough; your investigator will uncover omitted information one way or another whether via credit report checks, interviews with your associates, criminal or civil records, etc.

Joe Wallace is a 13-year veteran of the United States Air Force and a former reporter for Air Force Television News