But-For Causation Standard Applies to ADA Discrimination Claims


The U.S. Court of Appeals for the Ninth Circuit overruled its own precedent in holding that the but-for causation standard, and not the motivating factor causation standard, applies to claims of discrimination under the Americans with Disabilities Act.

In the 2005 case of Head v. Glacier Northwest, Inc., like seven of its sister circuits, the Ninth Circuit found that a plaintiff need only show that age was a motivating factor in an adverse employment decision, and not that it was the sole cause (but-for) of the decision. Subsequently, the U.S. Supreme Court issued its decision in Gross v. FBL Financial Services, Inc., in which it held that the but-for causation standard applied to claims under the Age Discrimination in Employment Act. The Supreme Court also declined to extend the motivating factor causation standard to Title VII claims in University of Texas Southwestern Medical Center v. Nassar, finding the but-for standard to apply in that context as well.

In light of the Supreme Court’s application of the but-for standard to ADEA and Title VII claims, the Ninth Circuit found that Head was no longer good law, as the same discrimination standards apply to the ADA. Accordingly, in Murray v. Mayo Clinic, the Ninth Circuit overruled Head and adopted the but-for causation standard for ADA discrimination cases. In so doing, it joined the other circuits – the Second, Fourth and Seventh – that have reconsidered this issue following the issuance of the Supreme Court’s decisions in Gross and Nassar.