California, like many other states, is an at-will state, meaning employers can discipline or fire employees at will (that is, without either needing or providing a reason to the employee). That said, there are situations in which the firing of an employee could be considered wrongful termination. This includes situations in which the employer is discriminating against the employee on the basis of age, race, sex, sexual orientation, disability, marital status, religion, national origin or gender identity. For example a woman cannot be fired simply because she is a woman.
Employees may also have an implied contract with their employer that could prevent the employer from firing the employee without just cause. These implied contracts may be informal and it is up to the court to determine if such a condition existed. The court bases this decision on a variety of factors including promises of job security, the employer’s employee handbook or policies, and job performance evaluations.
Finally, employees cannot be fired when the termination is based on a reason that is contrary to public policy. Firing an employee for refusing to do something illegal, for example, could be considered wrongful termination. Employers are also prohibited from firing, disciplining or retaliating against any employee who files a complaint with the government about illegal activities on the employer’s part.