A private lie detector test in the United States typically costs between $450 and $1,950, with most single-person exams priced between $500 and $800 and a median around $700. What you pay depends on the test’s purpose, the examiner’s credentials, your location, and how many questions the session has to cover.
Typical Prices by Test Type
Pricing data compiled from more than 150 testing locations across the country shows a lowest published rate of $450 and a highest of $1,950 for a standard single-person exam.
- Single-person exam with up to three questions: $450 to $800 for a roughly two-hour session. This covers most personal matters and basic screenings.
- Single-issue or specific-incident exam: $500 to $900 when the test focuses on one event, such as a theft allegation or a specific question in a relationship dispute.
- Multi-topic exam: $700 to $1,200 or more when several issues need separate question sets and the session runs past two hours.
- Couples testing: two people tested back-to-back in the same appointment save an average of about $164 compared with booking two separate exams. Each person is still examined privately.
- Group rates for three or more people: per-person costs drop roughly 16 percent, which is common in workplace investigations involving multiple employees.
Government agencies that polygraph their own employees usually absorb the cost, so applicants for law enforcement or intelligence positions generally pay nothing out of pocket. When a private attorney or employer arranges a test, who pays depends on the agreement between the parties.
What Changes the Price
Geography matters more than most people expect. Examiners in major metro areas routinely charge 15 to 25 percent more than those in smaller cities because their overhead is higher. A $500 exam in a mid-size Midwestern city might run $650 or more in New York or Los Angeles.
The examiner’s background is the other big variable. Someone who spent 20 years running polygraphs for a federal agency charges more than a recently trained examiner building a practice. That premium reflects reputation and the kind of detailed written reports that hold up in legal settings. Under federal law, examiners who conduct workplace polygraphs where permitted must be licensed, bonded, or carry professional liability coverage, and those credentials get built into the price.
Purpose and complexity shift the cost too. A screening with two or three yes-or-no questions takes less time than a multi-issue exam. Legal-related tests sit at the higher end because they often require more thorough documentation, extended pre-test interviews, and sometimes expert testimony afterward, which is billed separately.
What the Fee Covers
The quoted fee generally covers the full appointment: a pre-test interview, the chart collection where sensors record your physiological responses, and the examiner’s analysis producing a result of no deception indicated, deception indicated, or inconclusive. Most examiners include a written report in the base price.
Several things are almost never included. Expert witness testimony if your case goes to court can add $150 to $300 per hour or more on top of the exam cost. Examiner travel to your location and rush turnaround on reports also get billed separately.
If you don’t speak English fluently, you’ll likely need an interpreter, and examiners generally expect the client to arrange and pay for one. Interpreters familiar with polygraph procedures charge roughly $50 to $100 per hour, and sessions involving translation run three to four hours, so budget an extra $150 to $400.
Deposits and Cancellations
Most examiners require a non-refundable deposit to hold your appointment, commonly around $100. Cancel with at least 48 hours’ notice and you can usually reschedule without losing the deposit. Cancel later, skip the appointment, or show up more than 15 minutes late, and you’ll forfeit the deposit and possibly the full exam fee. If you stop the test mid-session, expect to lose the entire amount. Policies vary, so confirm them before booking.
Is It Worth Paying For?
The American Polygraph Association points to studies since 1980 showing accuracy rates between 80 and 98 percent. Critics call those same studies methodologically weak.1National Academies Press. The Polygraph and Lie Detection What you’re paying for is not a certainty machine. Inconclusive results happen more often than examiners advertise, and a retest means paying again.
If you’re buying a polygraph for a legal matter, know that most federal and state courts treat results as inadmissible. No federal statute or rule of evidence specifically addresses polygraph admissibility, and the majority of courts exclude them outright. Some courts allow results when both parties agree to admissibility in advance, or to support or challenge a witness’s credibility, but these are exceptions.2U.S. Department of Justice. 262. Polygraphs – Introduction at Trial Spending $700 expecting a polygraph to clear your name in court is one of the most common and expensive misunderstandings in this area. Talk to your attorney before booking.
When an Employer Wants You to Take One
Most private employers cannot require, request, or even suggest that an employee or job applicant take a polygraph. The Employee Polygraph Protection Act prohibits using results, asking about them, or punishing you for refusing.3Office of the Law Revision Counsel. 29 USC Ch. 22: Employee Polygraph Protection
Three gaps in the law matter. Government employers at every level are not covered, which is why law enforcement and intelligence agencies routinely polygraph applicants. Security firms, armored car companies, alarm services, and pharmaceutical manufacturers and distributors can polygraph job applicants under strict procedural rules. And any private employer may request a polygraph from a specific employee during an active investigation into theft, embezzlement, or sabotage that caused a measurable financial loss, but only if the employee had access to what went missing and there’s a reasonable basis for suspicion.4U.S. Department of Labor. Employee Polygraph Protection Act
Even where testing is permitted, the employer must give you written notice explaining the investigation, your right to refuse, and the limits on how results can be used. You can stop the test at any time. Results alone cannot be the sole basis for any adverse action against you.5U.S. Department of Labor. Fact Sheet 36: Employee Polygraph Protection Act of 1988
Finding a Qualified Examiner
The American Polygraph Association runs a searchable directory filterable by location.6American Polygraph Association. Member Directory Search The American Association of Police Polygraphists publishes a list of certified members, which helps if your situation involves a law enforcement context.7American Association of Police Polygraphists. Certified Members
About half of U.S. states require polygraph examiners to hold a state-issued license, and the APA maintains a list of those state licensing boards.8American Polygraph Association. State Licensing Boards and Associations In states without licensing, professional association membership is your main quality signal. Ask whether an examiner completed an APA-accredited training program and whether they meet the APA’s requirement of 30 hours of continuing education every two years.
When you contact an examiner, ask in writing what the fee covers before you commit. Confirm whether the written report is included, the cancellation policy, how long the session will take, and whether they carry professional liability insurance. If the test is for a legal matter, ask about their experience testifying and whether testimony is billed separately. An examiner who gets vague about pricing or credentials is telling you something worth listening to.