But-for standard

Jack Gross began working for FBL Financial Group, Inc. in 1971. As of 2001, Gross held the position of claims administration director. In 2003, when he was 54 years old, FBL reassigned Gross to the position of claims project coordinator while transferring many of his former responsibilities to a newly created claims administration manager position. FBL assigned that new position to Lisa Kneeskern, who had previously been supervised by Gross and who was then in her early forties. Although Gross and Kneeskern received the same compensation after the changes, Gross viewed the reassignment as a demotion because of the reallocation of his job responsibilities. In April 2004, Gross filed suit against FBL in federal district court alleging that the reassignment violated the Age Discrimination in Employment Act of 1967. At trial, Gross introduced evidence suggesting that his age had played a role in FBL's decision. FBL defended the reassignment on the grounds that it was part of a corporate restructuring and that Gross's new position was better suited to his skills. At the close of trial and over FBL's objections, the district court instructed the jury that it must return a verdict for Gross if he proved by a preponderance of the evidence that he had been demoted and that his age was a motivating factor in the decision. The court further instructed the jury that the verdict must be for FBL if it proved by a preponderance of the evidence that it would have demoted Gross regardless of his age. The jury returned a verdict for Gross and awarded him $46,945 in lost compensation. FBL appealed to the United States Court of Appeals for the Eighth Circuit, which reversed the district court's judgment and remanded for a new trial. The court of appeals held that the jury instructions were flawed because they permitted the burden to shift to FBL upon a showing of any evidence that age was a motivating factor rather than requiring direct evidence under the framework from Price Waterhouse v. Hopkins. Because Gross had conceded that he presented no direct evidence of discrimination, the Eighth Circuit concluded that he should have been held to the ordinary burden of proving that age was the determining factor in FBL's decision. The Supreme Court granted certiorari to review the case.

In the mid-1960s through 1987, the plaintiffs worked as grinders at the General Dynamics Corporation Electric Boat facility in Groton, Connecticut, where their duties required them to use pneumatic hand tools manufactured by the defendants Chicago Pneumatic Tool Company, Stanley Works, and Dresser Industries, Inc., to smooth welds and metal surfaces. During this employment the plaintiffs developed permanent vascular and neurological impairment of their hands, manifesting as blanching of the fingers, pain, numbness, tingling, reduction of grip strength, cold intolerance, and clumsiness, symptoms diagnosed as hand arm vibration syndrome. Ronald Guameri, an industrial hygienist at Electric Boat, performed extensive testing of tools used at the shipyard and found that a large number of the defendants' tools violated vibration exposure limits established by the American National Standards Institute and exceeded the threshold limit promulgated by the American Conference of Governmental and Industrial Hygienists. Richard Alexander, a mechanical engineering professor, testified that methods to reduce vibration through isolation, dampening, and balancing had been available to manufacturers for at least thirty-five years. Charles Suggs, a research engineer, testified that he had reduced vibration hazards in chain saws by inserting rubber mounts in the 1960s, reduced vibration by 70 percent in tools without handles in the 1970s by wrapping them with resilient foam rubber and a metal sleeve, and in 1988 reduced vibration levels in the defendants' die grinders by between 35 and 60 percent using similar techniques. After a six-week trial the jury returned verdicts awarding the plaintiffs compensatory damages on their design defect claims, found that the defendants had provided inadequate warnings but awarded no damages on that claim because the plaintiffs failed to prove causation, and declined to award punitive damages. The defendants appealed from the judgment, and the plaintiffs cross-appealed. The Supreme Court of Connecticut transferred the appeal and cross-appeal from the Appellate Court to itself pursuant to Practice Book § 4023 and General Statutes § 51-199(c). Electric Boat followed a regular maintenance program involving daily inspection of tools. It purchased chucks and other replacement parts from outside vendors. It periodically removed certain safety features and used longer burr attachments on the tools.

The University of Texas Southwestern Medical Center, a teaching hospital affiliated with the University of Texas, hired Naiel Nassar, a physician of Middle Eastern descent, first as a medical resident in 2001 and later as an assistant professor in the Department of Internal Medicine in 2006. Nassar's direct supervisor was Dr. Michael Levine, the Chief of Infectious Disease Medicine, and he also worked with Dr. Brian Becherer, the Medical Director of the hospital's employee health clinic. In 2007 and 2008, Nassar complained to his supervisors that he was being subjected to discrimination and harassment by Levine on the basis of his religion and ethnic heritage. In July 2008, Nassar was offered and accepted a position as a full-time faculty member in the Department of Internal Medicine. In August 2008, Nassar resigned from his faculty position in a letter stating that the primary reason for his departure was the hostile work environment created by Levine's harassment. After Nassar resigned, Becherer sent a letter to the state medical board reporting that Nassar had resigned while under investigation for professional misconduct involving alleged improper billing practices. Nassar filed suit in the United States District Court for the Northern District of Texas alleging two claims under Title VII: status-based discrimination on the basis of his race, religion, and national origin, and retaliation for complaining about Levine's conduct. The case proceeded to trial before a jury. The District Court instructed the jury that Nassar could prevail on his retaliation claim if he showed that retaliation was a motivating factor in the hospital's decision to send the letter to the medical board. The jury found for Nassar on both claims and awarded him $3,000 in backpay and $400,000 in compensatory damages, which the District Court reduced to $300,000 pursuant to the statutory cap. The hospital appealed to the Fifth Circuit, which affirmed the retaliation verdict on the theory that the motivating-factor standard applied. The Supreme Court granted certiorari.

The three cases consolidated before the Supreme Court arose when employers fired long-time employees shortly after the employees revealed their homosexual or transgender status. Gerald Bostock worked for Clayton County, Georgia, as a child welfare advocate whose leadership earned the county national awards. After a decade with the county, Bostock began participating in a gay recreational softball league. Influential community members then made disparaging comments about his sexual orientation, and he was fired for conduct unbecoming a county employee. Donald Zarda worked as a skydiving instructor at Altitude Express in New York for several seasons. After mentioning that he was gay, he was fired days later. Aimee Stephens worked at R. G. & G. R. Harris Funeral Homes in Michigan, presenting as male when hired. After two years she began treatment for gender dysphoria and wrote a letter stating she planned to live and work full-time as a woman. The funeral home fired her before she left for vacation. Each employee sued under Title VII of the Civil Rights Act of 1964 alleging unlawful discrimination on the basis of sex. The Eleventh Circuit held that Title VII does not prohibit employers from firing employees for being gay and dismissed Bostock's suit as a matter of law. The Second Circuit allowed Zarda's claim to proceed on the ground that sexual orientation discrimination violates Title VII. The Sixth Circuit reached the same conclusion in Stephens's case regarding transgender status. Both Zarda and Stephens passed away during the proceedings, but their estates continued to press the claims. The Supreme Court granted certiorari to resolve the disagreement among the courts of appeals over the scope of Title VII's protections for homosexual and transgender persons.