In August 2020, Niemeyer dissented from the 2-1 majority in G. G. v. Gloucester County School Board. In a 2-1 decision, the court ruled for Gavin Grimm, a transgender man who had sued the Gloucester County School Board in Virginia who had prohibited him from using the boy's bathroom. Niemeyer wrote in dissent “I readily accept the facts of Grimm’s sex status and gender identity and his felt need to be treated with dignity. Affording all persons the respect owed to them by virtue of their humanity is a core value underlying our civil society. At the same time, our role as a court is limited. We are commissioned to apply the law and must leave it to Congress to determine policy. In this instance, the School Board offered its students male and female restrooms, legitimately separating them on the basis of sex. It also provided safe and private unisex restrooms that Grimm, along with all other students, could use. These offerings fully complied with both Title IX and the Equal Protection Clause.”