Workers, businesses, and their lawyers face a different landscape for litigating under the Fair Labor Standards Act.

The U.S. Supreme Court abandoned a long-standing canon for how to apply exemptions to the Fair Labor Standards Act’s minimum wage and overtime requirements. An employee who works more than 40 hours per week generally is eligible for time-and-a-half pay for those extra hours under the Fair Labor Standards Act unless an exemption applies.

On April 2, the court ruled 5-4 that the...