The unanimous decision was issued after the California Supreme Court ruled in February that Apple violated state law by not compensating workers for the time spent during security checks of bags and employees' iPhones.
The California Supreme Court ruled that the time employees spend while awaiting and undergoing the company's exit searches are compensable “hours worked” under California law when subject to the control of an employer.
A spokesperson for Apple did not immediately return FOX Business's request for comment.
According to court documents, Apple's search process can take from five to 20 minutes to complete, and up to 45 minutes on the busiest days. Failure to comply with the process can result in termination of employment.
In November 2015, Apple won at the trial level in the U.S. District Court for the Northern District of California, which found employees chose to bring bags to work and thus subject themselves to the company’s search policy.
On appeal, however, the Ninth Circuit asked the state Supreme Court to interpret California law. Following the high court's decision, the Ninth Circuit rejected Apple's argument, ruling that it was "irrelevant."
"Those purported disputed facts pertain solely to individual remedies, not to the main legal question as to classwide relief," the court said.
The Ninth Circuit has reversed the original district court decision to grant of Apple's motion for summary judgment, which means the case was decided without a trial, and has granted the employees' summary judgment motion.
The class-action lawsuit was brought on behalf of more than 12,000 current and former hourly employees who have worked in Apple's stores in California since July 25, 2009.
"We are very pleased with the Ninth Circuit’s decision and believe it correctly resolved a long-standing and disputed issue of liability," Brett Gallaway, a lawyer representing the workers, told FOX Business in a statement. "We are also very proud of our team’s ongoing efforts and persistence throughout this litigation."