The Ninth Circuit Court of Appeals in a case entitled Murray v. Mayo Clinic, joined four other Circuit Courts of Appeal in holding that a “but for” causation standard applies in ADA discrimination claims.

This standard is considered to make it more difficult for employees to prove discrimination claims than what had been applied previously and is referred to as “a motivating factor standard.” The court reasoned that this change was required to comport with two earlier United States Supreme Court rulings that had adopted a similar standard based on similar statutory language found in the federal law prohibiting age discrimination in employment.

Using this new standard, ADA discrimination plaintiffs bringing a claim under 42 U.S.C. § 12112, which bars discrimination “on the basis of disability,” must now show that the adverse employment action would not have occurred but for the disability discrimination.

Under the former standard, a jury could have found an employer had violated the ADA even if the employer proved that it had a “mixed motive” for the adverse action, i.e., both legitimate and illegitimate reasons.

While employers can rejoice about this important change, any celebration should await review of their applicable state disability discrimination practice.

Many states have adopted standards that are different from what is afforded by this recent interpretation of federal law. Indeed, employees in those states may eschew federal claims in favor of a more liberal state law cause of action. Because employees can, and most often do bring claims under both federal and state law, juries will now face the unenviable task of applying two different legal standards that could yield different results: no liability under federal law, but liability under state law.

According to Bryan Hawkins in the Sacramento office of Stoel Rives LLP, California’s ADA equivalent “the Fair Employment and Housing Act” requires that plaintiffs prove that the discrimination occurred “because of” their disability.

California courts have interpreted this to require proof the disability was a substantial motivating factor behind the discrimination, rather than simply a motivating factor. This puts California’s standard somewhere between the “motivating factor” standard and the “but for” standard. With that being said, most California plaintiffs plead violations of the Fair Employment and Housing Act rather than the ADA, so attorney Bryan Hawkins doesn’t believe Murray will provide California employers with much (if any) relief.