Must a company give a reason for not hiring, reassigning, failing to promote, or firing me?

Unfortunately, companies don’t have any obligation to tell an employee why they do or do not make some employment decision. However, in many cases they do because they don’t want to leave the employee in the dark, especially if they’re doing something that is possibly wrongful or illegal. There’s no requirement that an employer give you a reason for not being hired for a position, but if you believe that a job action’s been taken for some reason that’s not legitimate, you should consult with an attorney because you may have a claim against your employer if the reason you believe was discriminatory.