Employees who sue for age discrimination are no longer required to prove the action was intentional.

The U.S. Supreme Court ruled 5-to-3 in favour of an interpretation of the federal law that prohibits age discrimination in employment. This means that employees can show their employer’s policies had a discriminatory impact on older workers, regardless of motivation. The decision removes a requirement imposed by several lower federal courts that requires employees to produce proof of motivation, an elusive requirement that has caused many ageism lawsuits to be dismissed before trial.

At the same time, the Supreme Court decision allows employers to defend themselves by proving that a challenged policy was based on "reasonable factors other than age". The ambiguity in interpretation of the law has been one of growing importance in recent years, since half of the American workforce within five years will be over age 40, the age at which the law’s protection applies.