Gross v. FBL: Private-Sector ADEA Claims Require Proof That Age Made the Difference

Review the primary official source.

Gross v. FBL Financial Services, 557 U.S. 167 (2009), concerns causation under the Age Discrimination in Employment Act for a private-sector disparate-treatment claim. The Court held that age must be the but-for cause of the challenged decision; proof that it was merely one motivating factor does not shift the burden to the employer.

The demotion and jury instruction

Jack Gross alleged that his employer demoted him because of age. A jury was told to find for him if age played a part in the decision, unless the employer proved it would have made the same decision anyway. The verdict favored Gross, but the instruction imported a mixed-motives framework associated with Title VII.

The Eighth Circuit ordered a new trial. The Supreme Court agreed the causation instruction could not be sustained under the ADEA as written, though its reasoning did not establish that the employer's stated reasons were true.

Text and burden of persuasion

The ADEA makes it unlawful to act against an individual 'because of' age. The Court read that language as requiring the employee to prove by a preponderance that the adverse action would not have occurred but for age. Unlike Title VII's amended provisions, the ADEA lacked a statutory mixed-motives rule shifting the ultimate burden to the employer in this type of case.

But-for causation need not mean age was the only factual influence. It asks whether the outcome would have been different without the prohibited factor. The employee retains the ultimate burden of persuasion, using direct or circumstantial evidence as the record permits.

Limits that prevent overreading

The decision vacated and remanded; it did not decide whether Gross could prove his claim under a correct instruction. Gross addresses the private-sector ADEA provision at issue. The Supreme Court later addressed different statutory wording for federal personnel actions in Babb v. Wilkie; California FEHA has its own framework.

A practical case review compares job duties before and after the change, decisionmaker statements, contemporaneous performance records, comparator treatment, and the employer's stated reason. The case analysis explains the burden; the companion Insight in this slate helps organize the decision record without assuming a particular outcome.

The evidentiary boundary

The jury instruction placed a same-decision burden on the employer once age played a part. The Supreme Court found that transfer from Title VII unwarranted because Congress had written a different ADEA provision. The distinction controls the ultimate burden of persuasion, not whether circumstantial proof is allowed. A worker may use comparative treatment, timing, remarks, and inconsistencies to establish causation, but the factfinder must still ask whether the adverse decision would have occurred without age. Gross did not adjudicate the truth of FBL’s account or decide every federal-sector and state-law age claim.

“the plaintiff retains the burden of persuasion”

The official decision states this at 557 U.S. 167, 177. Read the complete reasoning and procedural history before applying the quoted passage.

The private-sector ADEA provision, 29 U.S.C. § 623(a)(1), uses the phrase “because of” age. Gross construed that wording rather than importing Title VII’s amended mixed-motives text.

For a practical evidence checklist, see Demoted After 40? Build the Decision Record Before an Age-Bias Claim.

What this means in practice

• Identify the specific employment action and decision date.
• Collect age-related remarks, comparator records, performance history, and shifts in job duties.
• Test the employer’s explanation against contemporaneous documents.
• Do not import Title VII mixed-motives instructions into a private-sector ADEA claim without checking current law.

Related reading: Employment litigation practice; Employment claim deadlines; Retaliation and wage-claim guide.