Can an employee who engaged in protected conduct sue for retaliation for a negative performance review?
Probably not, at least not yet. The employee must suffer a so-called “tangible, adverse employment action in order to file a suit.” Generally speaking, an adverse employment action must result in a monetary loss in order to be tangible. Therefore, a negative performance review is probably not tangible enough to support a retaliation claim. However, if the negative review is part of a campaign of retaliatory harassment, or if it is used to justify a retaliatory discharge, it may become actionable at that point.