In a 5-4 decision delivered by Justice Clarence Thomas, the U.S. Supreme Court in Gross v. FBL Financial Services, Inc. (pdf) has held that a plaintiff bringing a claim under the Age Discrimination in Employment Act (ADEA) must show by a preponderance of the evidence that age was the “but for” cause of the employer’s adverse employment decision, and that an employer need not show that it would have made the same decision regardless of age, even if the employee produces some evidence that age may have been a contributing factor in the decision. Thus, the burden-shifting framework in mixed motive Title VII cases does not apply to age discrimination claims under the ADEA.

The petitioner in this case, Jack Gross, filed a claim in district court against his employer, FBL Financial Group, Inc. (FBL), alleging that he was demoted on account of his age in violation of the ADEA. At trial, the judge instructed the jury that it must find in the plaintiff’s favor if he proved, by a preponderance of the evidence, that age was a motivating factor in the employer’s decision. Age would be considered a “motivating factor” if it “played a part or role” in the employer’s decision. The jury was further instructed that the employer bore the burden of proving that it would have demoted Gross regardless of his age. In essence, the judge instructed the jury under the “mixed-motive” discrimination standard established by Price Waterhouse v. Hopkins, 490 U.S. 228 (1989), a Title VII sex discrimination case in which the plaintiff alleged that both permissible and impermissible considerations played a part in her failure to make partner. In such a mixed motive situation, the Court reasoned, if a plaintiff can show that unlawful discrimination plays a motivating or substantial factor in the employment decision at issue, the burden of persuasion shifts to the employer to prove that it would have made the same adverse decision regardless of the discriminatory factor. The jury in Gross’s case found in his favor. On appeal, the Eighth Circuit reversed and remanded, finding that the jury had been improperly instructed. Because Gross did not present direct evidence of discrimination, the Court of Appeals held that the lower court erred in requiring the burden of persuasion to shift to the employer to prove that it would have made the same decision regardless of age.

The Supreme Court vacated the Eighth Circuit’s decision, holding that an employer does not need to show that it would have acted regardless of age, even if the plaintiff has provided direct evidence that age was a motivating factor. The Court reasoned that “[u]nlike Title VII, the ADEA’s text does not provide that a plaintiff may establish discrimination by showing that age was simply a motivating factor.” The Court placed great emphasis on the fact that when Congress amended Title VII to explicitly authorize discrimination claims in mixed motive scenarios, it did not similarly amend the ADEA, even though it made other contemporaneous changes to this law. According to the Court, “[w]hen Congress amends one statutory provision but not another, it is presumed to have acted intentionally.”

Additionally, the Court relied on the precise language contained in the ADEA that: “[i]t shall be unlawful for an employer . . . to fail or refuse to hire or to discharge any individual or otherwise discriminate against any individual with respect to his compensation, terms, conditions, or privileges of employment because of such an individual’s age.” (emphasis added). Lifting the definition of “because of” from the dictionary, Justice Thomas reasoned that in the ADEA’s context, this phrase means the reason the employer decided to act. Thus, to succeed with an ADEA claim, the employee must show that age was the “but for” cause of the employer’s adverse decision, and nothing in the Act indicates that Congress intended any exception to this burden of proof.

A relief to employers, this case should make it substantially more difficult for many employees to succeed in their age discrimination claims. Unlike the burden-shifting scheme in Title VII mixed motive cases, the burden of proving that age was the decisive factor in the employer’s decision remains with the plaintiff. Time will tell if the current Congress will move to amend the ADEA to counter the results of this decision, as it has with other recent Supreme Court decisions favorable to employers such as the Lilly Ledbetter decision.

Chief Justice Roberts, along with Justices Scalia, Kennedy, and Alito, joined in this opinion. Justice Stevens filed a dissenting opinion, in which Justices Souter, Ginsburg, and Breyer joined. Justice Breyer also filed a dissenting opinion in which Justices Souter and Ginsburg joined.