Age Discrimination's Higher Bar: How 'But-For' Causation Affects NJ ADEA Claims

An age discrimination claim under the ADEA requires proof that the employment decision would not have happened without the employee’s age. This means meeting the “but-for” causation standard.

Employers commonly rely on performance concerns, company reorganizations, or business needs to explain decisions affecting older employees. Our team at Brandon J. Broderick regularly reviews these disputes, in which the employer’s stated reason is given close scrutiny. The analysis focuses on the surrounding facts and comparisons between older and younger workers. 

In this guide, we discuss how the but-for causation standard applies in ADEA claims, why these cases require a higher burden of proof, what evidence supports an employee’s position, and when to contact an employment lawyer in New Jersey. 

The ADEA and “Because Of” Age Discrimination: How But-For Causation Applies in NJ Claims

Federal claims start with the Age Discrimination in Employment Act of 1967, known as the ADEA. Congress passed the law to protect workers 40 and older. An employer is not allowed to fire, demote, refuse to hire, or otherwise harm someone "because of such individual's age." Coverage includes private employers with 20 or more employees, along with state and local governments, employment agencies, and labor unions.

Those two words, "because of," decide how hard an age case is to win. Federal courts read them literally, so age bias has to be the true reason behind the employer's decision rather than one of several reasons mixed. Lawyers call it "but-for" causation. It means a worker has to show the decision would not have happened but for age. In an earlier case, Hazen Paper Co. v. Biggins, the Supreme Court described the idea that age has a significant influence on the outcome. Federal courts still refer to the case today.

The standard requires a direct connection between the protected trait and the employment decision. If an employer relies on multiple reasons for a termination and one legitimate reason alone would have produced the same outcome, the employee doesn’t satisfy the ADEA’s but-for causation standard. 

Other discrimination laws set a lower bar. In 1991, Congress updated Title VII of the Civil Rights Act, the law covering race, sex, religion, color, and national origin. After the update, a worker wins by showing that a protected trait was a "motivating factor" in the decision. 

It applies even when the employer had other reasons too. Congress changed the ADEA later and left the motivating-factor language out. Courts read this as a deliberate choice, since lawmakers rewrote one law and skipped the other at the same time.

But-for causation shapes federal claims in three ways:

• Workers carry the burden of proof from start to finish. At no point does the employer have to prove it did nothing wrong.
• Age does not have to be the only reason for the decision, but it does have to be the deciding one. Evidence showing age came up somewhere in the process is not enough.
• Proof works by a preponderance of the evidence, which means more likely than not. Direct proof, such as a manager's biased comments, and circumstantial proof, like a pattern of forcing older staff out, both count.

The ADEA applies a but-for causation standard in federal claims. New Jersey law uses a different standard. Our legal team at Brandon J. Broderick looks closely at these differences because the rules affect the evidence needed to support the claim. Similar protections also extend to severance agreements, where employers must follow specific rules when asking workers over 40 to release potential ADEA claims. 

How Gross v. FBL Financial Services Applies to Age Bias Claims in New Jersey

Gross v. FBL Financial Services, Inc. (2009) created the modern standard. Jack Gross worked at FBL Financial Group in Iowa starting in 1971 and spent more than three decades with the company. 

In 2003, at 54, FBL reassigned him from claims administration director to claims project coordinator. His pay stayed the same, but many of his duties went to a newly created position held by a younger employee. Gross viewed the move as a demotion and sued under the ADEA. He argued the company based the reassignment at least in part on his age.

At trial, the judge told the jury to rule for Gross if age was a motivating factor in the decision. He also told them to rule for FBL if the company proved it would have reassigned Gross regardless of age. Jurors sided with Gross and awarded him $46,945 in lost pay. The Eighth Circuit reversed the verdict, and the Supreme Court agreed to sort out how age cases with mixed motives should work.

On June 18, 2009, a majority led by Justice Clarence Thomas went further than either side expected. Instead of answering the narrow question about jury instructions, the court ruled that motivating-factor claims don’t exist under the ADEA. Two holdings came out of the decision:

• ADEA plaintiffs have to prove age was the but-for cause of the harm, by a preponderance of the evidence. 
• Burden of proof never shifts to the employer. Under Title VII, an employer facing direct evidence of bias has to prove it would have made the same decision anyway. ADEA defendants owe no such proof, even after a worker shows age played some role.

Four dissenting justices objected that the majority answered a question the parties never briefed. They also noted the ruling discarded two decades of precedent from Price Waterhouse v. Hopkins. None of it changed the outcome. 

Lower courts followed this approach, and employers gained a powerful defense at the early stages of litigation. In many cases our attorneys build, the dispute centers on whether the employer’s stated reason truly explains the decision. Employers often rely on separate justifications to argue that the outcome would have been the same. 

New Jersey’s LAD Offers a Different Path From the ADEA Causation Standard 

New Jersey workers rarely depend on the ADEA alone. The state has its own law, the New Jersey Law Against Discrimination. It bans age bias on terms far more favorable to employees, and the state courts never adopted the Gross standard for claims brought under it.

The LAD applies to every employer operating in New Jersey, no matter its size, while the ADEA requires 20 or more employees. Protection under state law starts at age 18 instead of 40. After the New Jersey Supreme Court's 1999 decision in Bergen Commercial Bank v. Sisler, the law also protects workers treated worse for being too young.

Causation is the biggest difference. New Jersey courts ask whether age was a determinative factor in the employer's decision, using the step-by-step test from McDonnell Douglas Corp. v. Green. 

It is a noticeably lighter burden than proving the decision would never have happened otherwise. Workers with direct evidence, such as a decisionmaker's own words, get one more advantage. Once direct proof is in, the burden shifts. The employer has to prove it would have made the same decision anyway. Many cases proceed under the LAD for exactly these reasons.

Remedies and deadlines also favor the state route:

• LAD damages include emotional distress, plus punitive damages in the worst cases. ADEA recovery covers lost pay and benefits only, doubled when the violation was willful.
• Workers file LAD claims directly in Superior Court within two years of the discrimination, and no agency step is required first. Filing with the New Jersey Division on Civil Rights is an alternative with a 180-day deadline, though a worker picks one path or the other, not both at once.
• ADEA claims require a charge with the Equal Employment Opportunity Commission before any lawsuit, filed within 300 days of the discriminatory act in New Jersey.

Meeting the Higher Burden of Proof for Older New Jersey Workers 

Gross made federal claims harder, but not impossible. But-for causation doesn’t mean age has to be the only reason for a decision, and circumstantial evidence still counts in full. Workers who gather the right proof continue to win verdicts and defeat early dismissal motions.

Strong evidence includes:

• Related biased remarks by decision-makers, especially comments tied to the decision itself. Talk about wanting “fresh energy” on the team or repeated questions about retirement plans belong in this category.
• Replacement by a much younger worker, or a layoff round that removed older employees while keeping younger colleagues with similar jobs and records.
• Comparator evidence, meaning younger employees kept their jobs after the same conduct that the employer used to justify firing an older worker.
• Proof of pretext, meaning the employer's stated reason is false. Jurors who decide the official explanation is untrue are allowed to conclude the real reason was age.

Congress has tried to undo Gross directly. The Protecting Older Workers Against Discrimination Act, first introduced after the decision, would restore the motivating-factor standard for age claims and put them on the same footing as race and national origin claims. 

It passed the House in January 2020 and again in June 2021. Members of both parties reintroduced it as recently as 2025, but the Senate has never voted on it. Until it becomes law, Gross remains binding.

The EEOC received 88,531 discrimination charges in fiscal year 2024, a 9% increase over the prior year. Age claims have made up a substantial share of the agency's caseload for decades. 

Employees deciding between an ADEA claim and a New Jersey LAD claim benefit from reviewing the evidence early, including emails, performance reviews, and witness information. The law that applies affects what must be proven, who carries the burden, and the potential outcome of the case. 

If you believe your termination or layoff involved age bias, contact us today for guidance on your options.