The EPPA prohibits most private employers from using polygraph tests for pre-employment screening or during the course of employment. Several categories of employees are exempt from the EPPA. These include government employees and experts, consultants, and employees of Federal contractors engaged in national security intelligence or counterintelligence functions. Three groups of employees are exempt from the polygraph prohibition under certain conditions. They include employees who are reasonably suspected of involvement in a workplace incident that results in economic loss or injury to the employer; prospective employees of private armored car, security alarm, and security guard firms; and some current and prospective employees of firms engaged in the manufacture, distribution, or dispensing of controlled substances. This article examines EPPA's effect in the context of other related State or local laws, how the polygraph is defined under the EPPA, the act's prohibitions regarding lie detector use, and how employees and prospective employees are given notice of the EPPA provisions. Other topics considered are how an employer administers polygraph tests in the course of economic loss or injury to the employer, the types of economic loss or injury covered under EPPA, how an employer may administer a polygraph test to employees exempt from EPPA, and which prospective employees may be tested. Also addressed are the steps an employer can take if polygraph results are adverse for the employee, examiner qualifications, examinee rights, disclosure of results, and what EPPA means for the polygraph industry and employers who want to use polygraphs.