How much does a private polygraph test cost? Trained polygraph examiners administer lie detector tests for a fee. The typical cost is between $200 and $2,000. The specific cost usually increases with the length of the test.

Although there is some debate in the scientific community regarding the efficacy of polygraphs, assessments of polygraphy by scientific and government bodies generally suggest that polygraphs are inaccurate, may be defeated by countermeasures, and are an imperfect or invalid means of assessing truthfulness.

The federal government uses the polygraph exam to understand an applicants' past behavior, personal connections, and personal integrity. Almost every Border Patrol Agent, Customs and Border Protection Officer, and Air and Marine Operations Agent who has joined CBP has taken, and passed, a Polygraph Exam.

Use an Online Lie Detector Test There are some that are completely free to use, though the accuracy is questionable.