There are many steps required in order to obtain a security clearance required for certain work with the U.S. Federal Government. The U.S. Department of State lays out an easy outline of the steps an individual must take in order to get one.
First, you need to be employed by an employer that has been investigated, adjudicated, and possesses the Facility Security Clearance (FCL) and is designated a Cleared Defense Contractor (CDC); alternatively, the employer may be a Federal agency (such as the Federal Bureau of Investigations) or U.S. military.
Secondly, your job must necessitate a requirement to possess a security clearance. Generally speaking, a job posting will denote whether or not an applicant must either possess or be eligible to possess a security clearance. Hiring officials determine whether a position will require a security clearance based upon the duties and responsibilities of the position. If the job requires access to classified information, a background investigation must be conducted. This is done after a conditional offer of employment is given to an applicant.
Not all clearances are the same. The most common kinds of clearances applied for include (in order of hierarchical level): Confidential, Secret, and Top Secret. The type of background investigation depends on the position’s requirements as well as the level of security clearance needed for the position. This process can take several months or even as long as a year (depending on the backlog of investigations being performed at the time).
Typically the first step of the investigation is your submission of Standard Form 86 (SF-86), which is typically submitted through the electronic Questionnaire for Investigation Processing (eQIP) accessible from any internet-connected computer. If this is your first time filling out SF-86, you should gather as much supporting information as possible. It is not uncommon for the 100+ page SF-86 form to take several hours to complete, as you will have to provide details about people you know, your family, your criminal record, your work and education histories, as well as locations you have lived - in some cases going back 10 years. Many of these entries require unique, non-family individuals (i.e. not listed elsewhere within the SF-86) who can testify that your statements are correct (think coworkers, roommates, landlords, etc). As a courtesy to those individuals, you may want to notify them that they may be contacted by the government in order to verify your statements. No section may be left unanswered.
Above all else do not lie on your SF-86 form. Besides being denied a clearance, U.S. Criminal Code (title 18, section 1001) provides that knowingly falsifying or concealing a material fact is a felony which may result in fines and/or up to five years imprisonment.
After completing the form, human resources submits the completed security package to the State Department’s Office of Personnel Security and Suitability. The package is reviewed for completeness and entered into a case management system. Your records (including a fingerprint check) are then reviewed, with a case manager going over your SF-86 and reaching out to contacts you listed for verification. At some point, you will be contacted for scheduling an in-person interview to go over any discovered discrepancies/omissions.
Finally, when the investigation is finished, security clearance adjudicators weigh the results against guidelines for security clearances. This is the final determination as to whether you will be granted your requested clearance.