The Supreme Court ruled on Friday that a retired Florida firefighter cannot sue her former employer under federal disability rights law for refusing to provide her the health benefits that she had once been promised.

Justice Neil M. Gorsuch wrote the opinion in a tangled decision, finding that because the alleged discrimination took place after the firefighter, Karyn Stanley, had retired and left her job, she could not bring a lawsuit claiming that she was discriminated against in the workplace.

Upholding a federal appeals court ruling, Justice Gorsuch wrote that the section of the Americans with Disabilities Act at issue in the case did not cover disability discrimination claims by retirees. In order to bring a successful claim, Justice Gorsuch wrote, a plaintiff must show that she held or wanted a job and “could perform its essential functions” at the time of the alleged disability-based discrimination.

In a dissent, Justice Ketanji Brown Jackson, joined, in part, by Justice Sonia Sotomayor, argued that the justices had abandoned protections for vulnerable retirees.

“Disabled Americans who have retired from the work force simply want to enjoy the fruits of their labor free from discrimination,” Justice Jackson wrote, adding that Congress had “plainly protected their right to do so” when it drafted the federal disability rights law.

Justice Sotomayor, in a separate writing, argued that a majority of the justices appeared in agreement that retirees may be able to bring disability discrimination claims for actions that occurred while they were still employed. Ms. Stanley might have been able to argue that this would apply in her case, too, Justice Sotomayor wrote, but the court had not been asked to weigh in on that question.