So, you've reached the point in your career when you need a security clearance. You may already have a security clearance of some type, but now you need a Top Secret or Sensitive Compartmented Information Clearance. Congratulations, you must have or are about to step into an interesting job.

Now, how do you get that impressive new clearance? Several things have to happen, but none of them is insurmountable providing you're the kind of person who can be trusted with such a clearance.

How to Get a TS or SCI Clearance

Usually your employer, whether government agency or civilian organization, decides that you need the clearance in your position. It's not something people can get to dress up their LinkedIn profiles. The process takes four to six months if nothing goes wrong. Things that could go wrong include you having a history of visiting certain blacklisted countries, having the wrong friends, using recreational drugs, or not being a naturalized or native-born U.S. citizen. These complications make obtaining a clearance difficult or impossible and certainly add to the time it takes to complete the process. Because it can cost a company a $15,000 nonrefundable investment to get an employee such a clearance, companies take the process seriously.

Pre-Investigation Phase

Provided you're a good candidate, the supervisor who makes the decision that you need the security clearance contacts the relevant government investigative agency (usually the National Background Investigations Bureau) and gets the ball officially rolling. You are thoroughly investigated, possibly even before knowing that you're up for a sensitive position. Credit checks, criminal history, banking history and tax records – all of it is examined.

Investigation Phase, Including Full Scope Polygraph

When the agency is certain you're a good candidate, you are given forms to fill out. Your answers must be correct and complete. The answers you give are investigated, and assuming all goes well, you're brought in for an interview. Because you're going for an elevated security clearance, a polygraph may be necessary to determine whether you're truthful. They are not always required; however, you should be prepared for this eventuality.

How Polygraphs Work

Polygraphs are not foolproof, and some courts do not recognize them as authoritative, but they are a useful measure of whether someone is under the kind of stress that evasion of questions in real time can produce. Polygraphs measure and graph the stress a person is under while answering a series of questions. You're asked a series of baseline questions to which you are told to answer truthfully. Then, you're asked another set of questions and instructed to lie. These questions give investigators examples to use when analyzing the answers to the real interview questions.

Full Scope Polygraph vs. CI Polygraph vs. Lifestyle Polygraph

A Full Scope Polygraph test, aka an Expanded Scope Polygraph or Full Scope Poly, is the most thorough form of polygraph test in use to screen security clearance candidates. As the name implies, it can include all the standard questions of both the Counterintelligence or CI Polygraph and the Lifestyle Polygraph tests and is designed to be exhaustive. The CI Polygraph focuses on questions such as, "Are you related to any terrorists," while the Lifestyle Polygraph questions focus more on your personal criminal history and drug use.

The topics examined during a Full Scope Polygraph can include espionage, sabotage, terrorism, deliberately damaging U.S. government information systems, deliberately compromising classified information, secretly contacting a foreign national or their agents, unauthorized disclosure or removal of classified information (whistleblowing), involvement with serious crime, involvement with illegal drugs in the preceding seven years, falsification of the security application and more. Any question the examiner deems relevant is asked.

The investigation process is thorough, time-consuming and stressful. However, polygraph operators are accustomed to making allowances for nervous TS and SCI Poly candidates. Good luck with your exciting new clearance.