SAN FRANCISCO (CBS SF) — A federal appeals court in San Francisco ruled Monday that workers’ previous salaries can’t be used to justify unequal pay for women and men doing the same job.

The 9th U.S. Circuit Court of Appeals, ruling in the case of a Fresno schools mathematics consultant, said different pay based on past salaries violates the federal Equal Pay Act of 1963.

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The late Circuit Judge Stephen Reinhardt wrote, “Prior salary is not job-related and it perpetuates the very gender-based assumptions about the value of work that the Equal Pay Act was designed to end.”

The court noted in a footnote that Reinhardt completed the lead opinion in the case before his death on March 29 at age 87 after more than 37 years on the bench.

Reinhardt wrote, “Salaries speak louder than words…. Although the Act has prohibited sex-based wage discrimination for more than fifty years, the financial exploitation of working women embodied by the gender pay gap continues to be an embarrassing reality of our economy.”

The plaintiff, Aileen Rizo, was a middle and high school math teacher from Arizona who was hired by the Fresno County Office of Education as a consultant in 2009 to train teachers in new ways of teaching math.

After three years on the job, she found she was paid more than $10,000 less than her male colleagues who were doing similar work and had either similar or less experience.

At the time, the county set the employees’ pay according to a 10-level salary schedule. New hires’ initial salary levels were based on their previous pay.

Rizo sued Fresno County Schools Superintendent Jim Yovino in federal court in 2014, claiming that her lower pay was illegal.

Monday’s decision was issued by a rarely convened 11-judge panel of the appeals court. Rizo appealed for review by the expanded panel after a three-judge appeals panel ruled in favor of Yovino. Earlier, a federal trial judge in Fresno sided with Rizo.

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The Equal Pay Act, signed in 1963 by President John F. Kennedy, requires equal pay for equal work, but makes exceptions for pay based on seniority, merit, productivity or “any other factor other than sex.”

Yovino’s lawyers claimed that previous salary was a valid factor “other than sex.”

But the appeals court majority said that a woman’s prior salary was not a valid consideration because it was likely to be tied to past discrimination.

It said legitimate other factors must be job-related, such as a prospective employee’s experience, educational background, ability or prior job performance.

All 11 judges on the panel agreed that the salary disparity was illegal in Rizo’s case.

The six-member majority of the court, led by Reinhardt, said that in general, previous salary cannot be a consideration even when combined with other factors.

The five other judges said in concurring opinions that they believed previous salary could sometimes be considered in conjunction with other factors.

Yovino’s lawyer, Michael Woods, said the superintendent will appeal to the U.S. Supreme Court for further review.

“We remain confident that the policy of determining salaries by the Fresno County superintendent of schools, which was in effect through December 31, 2015, was absolutely gender-neutral, objective and effective in attracting qualified applicants and complied with all applicable laws,” Woods said in a statement.

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