Also on June 24, 2013, the Supreme Court addressed the standard courts should apply to determine whether an employer violates Title VII's anti-retaliation provision. Because of a statutory amendment in 1991, courts apply a "motivating factor" test for Title VII discrimination based on race, color, national origin, sex, and religion. The anti-retaliation provision however is in a separate section of Title VII, and the Supreme Court has decided to apply the traditional test: retaliatory animus is not the "cause" of the materially adverse action if the materially adverse action would have occurred without the animus. This is what the courts call "but-for" causation. The adverse action would not happen but for the retaliatory animus. University of Texas Southwestern Medical Center v. Nassar, No. 12-484 (U.S. June 24, 2013).

In reaching this conclusion, the Court found the EEOC's position on this issue to be unpersuasive. The EEOC failed to appreciate the "interplay" among statutory provisions on status-based discrimination, the motivating-factor amendment, and the anti-retaliation provision.