The justices, in a 9-0 decision, vacated a lower court ruling against the worker and clarified what is allowed under the Constitution in the often-contentious area of religious requests and employer-employee relations. 

The case will now go back to the U.S. Third Circuit Court of Appeals with new instructions from the high court that are more favorable to religious employees.

Gerald Groff, an evangelical Christian, began working with USPS prior to the carrier signing an agreement with Amazon to facilitate Sunday deliveries. USPS initially granted his request to not work on Sundays by transferring him to another branch. But when that branch, too, implemented Sunday delivery, Groff was told he must work Sundays. He resigned and sued USPS.

Writing the majority opinion Justice Samuel Alito wrote:

“We think it is enough to say that an employer must show that the burden of granting an accommodation would result in substantial increased costs in relation to the conduct of its particular business. Courts must apply the test in a manner that takes into account all relevant factors in the case at hand, including the particular accommodations at issue and their practical impact in light of the nature, size and operating cost of an employer.'”