Regardless of whether a worker has a contract or is working at will, there are certain reasons for which an employer may not terminate employment. It is illegal, according to state and federal laws, to fire an employee because of: -Discrimination: Federal anti-discrimination laws are quite extensive and make it illegal to fire an employee based on race, gender, nationality, disability, religion, age, and pregnancy (including recent birth). State laws are often more stringent and may include laws against discrimination based on marital status, sexual orientation, and more State laws may also apply to a wider range of employees. The fair employment office of each state can provide the specific prohibitions and the employers to whom they apply. -Retaliation: An employee cannot be fired for seeking to enforce his or her rights. If an employee feels that he or she has been discriminated against, he or she has the right to file a complaint, consult an attorney, cooperate with an investigation or file a lawsuit. All of these actions are protected by law. -Refusal to Take a Polygraph Test: An employee has the right to refuse to take a polygraph (lie detector) test under the Federal Employee Polygraph Protection Act. -Alien Status: Provided that an employee is legally permitted to work in the US, it is illegal to fire that employee based on his or her status as an alien. This is stated in the Federal Immigration Reform and Control Act (IRCA). -Complaining about Health and Safety Violations: OSHA, the Federal Occupational Safety and Health Act, states that it is illegal to fire an employee for complaining about violations of federal or state health and safety laws. -Public Policy Violations: An employee cannot be fired for refusing to do something that most people would find morally or ethically wrong. The specifics vary from state to state, but some general reasons for illegal termination include: -refusal to commit or participate in a crime -complaining about illegal conduct in the workplace -voting -taking family leave Because there are many possible reasons for wrongful termination, it may be prudent to ask employees to sign release forms or agreements not to sue.