Employees bringing a claim of age discrimination under the Age Discrimination and Employment Act (“ADEA”) must prove that age was the “but-for” cause of the employer’s adverse action according to the U.S. Supreme Court’s decision issued on June 18, 2009. The Supreme Court has clarified that the employer does not bear the burden of proving that it would have taken the action regardless of the employee’s age. Gross v. FBL Financial Services, Inc. (No. 08-441, June 18, 2009).

After 32 years at FBL, Jack Gross was reassigned to a new position when he was 54 years old. Gross’s position was given to another employee in her early 40’s. Gross considered the reassignment a demotion even though there was no change in his compensation. He sued alleging that his reassignment violated the ADEA, which makes it unlawful for an employer to take adverse action against an employee “because of such employee’s age.”

At trial, Gross presented some evidence that suggested his reassignment was based at least in part on his age. Using the burdenshifting framework adopted by the Supreme Court in a sex discrimination case brought under Title VII (which prohibits discrimination based on race, sex, national origin, color and religion), the Gross trial court instructed the jury to find for Gross if FBL could not prove that it would have demoted Gross regardless of his age. The jury found in favor of Gross and awarded him $47,000 in lost compensation. FBL challenged the jury instructions on appeal.

The Supreme Court agreed with the Eighth Circuit Court of Appeals’ reversal of the jury verdict, but rejected the Court of Appeals’ application of the mixed-motive approach used in Title VII discrimination cases. Justice Clarence Thomas, writing the majority opinion for the Court, states that the ADEA does not provide that a plaintiff may establish discrimination by showing that age was simply a motivating factor. Rather, the ADEA’s requirement that the employer took action “because of” age means that the plaintiff must prove that age was “the reason” that the employer decided to act. In support, the Court relies heavily on the fact that Congress amended Title VII to allow for employer liability when discrimination “was a motivating factor for any employment practice, even though other factors also motivated the practice,” but did not similarly amend the ADEA even though it amended the ADEA in other respects.

This is a significant decision, especially as employers who are reducing their work force are likely to be subjected to more claims of age discrimination. If employers have business reasons for making decisions that adversely impact older workers, it may be very difficult for the older workers to prove that age was the reason for the decision without direct evidence of age bias. However, once again, the Supreme Court is inviting Congress to pass legislation to overturn its decision and we may see bills to amend the ADEA to allow for employer liability when age was “a motivating factor” as under Title VII.