Claims of unlawful age discrimination can be difficult to prove. An employer can only be held liable for age discrimination if the employee can show that her or she was directly or indirectly discriminated against because of age. It does not have to be intentional. In Gross v. FBL. Financial Services, Inc., No. 08-441, 557 U.S., (2009) the U.S. Supreme Court decided if there needs to be direct evidence of discrimination in a suit filed under the ADEA. In short, the answer is no. Instead, the plaintiff must prove that “but for” the employee’s age, the employer would not have taken the discriminatory action.