Updated at 2 p.m.

The U.S. Supreme Court, expanding the reach of the federal law banning age discrimination in the workplace, unanimously ruled Tuesday that state and local political subdivisions of any size must comply.

Justice Ruth Bader Ginsburg wrote the first opinion of the term in Mount Lemmon Fire District v. Guido, argued just five weeks ago. Justice Brett Kavanaugh did not participate in the case, which was argued on the term's first day—Oct. 1. He was not sworn into office until Oct. 5.

Mount Lemmon, an Arizona political subdivision, was sued after it terminated the employment of two of its oldest employees—John Guido, then 46, and Dennis Rankin, 54, both captains. Those employees alleged illegal age discrimination under the Age Discrimination in Employment Act, or ADEA.

Mount Lemmon's lawyer, E. Joshua Rosenkranz of Orrick, Herrington & Sutcliffe, argued in the Supreme Court that the federal law's 20-employee minimum requirement that applies to private employers also applied to state political subdivisions. Because the fire district had fewer than 20 employees, the ADEA did not apply, he said. The justices upheld the U.S. Court of Appeals for the Ninth Circuit's June 2017 ruling. (Watch the appellate oral argument below.)

The justices took the fire district's case to resolve a circuit split between the Ninth Circuit and the Sixth, Seventh, Eighth and Tenth circuits.

In analyzing the law's definition section, Ginsburg said the ADEA creates two separate categories: persons engaged in an industry affecting commerce with 20 or more employees; and states or political subdivisions with no specified number of employees.

“True, reading the ADEA as written to apply to states and political subdivisions regardless of size gives the ADEA, in this regard, a broader reach than Title VII,” she wrote, referring to the nation's major anti-discrimination law. “But this disparity is a consequence of the different language Congress chose to employ.” The better comparison, Ginsburg added, is the Fair Labor Standards Act, “on which many aspects of the ADEA are based” and which also ranks states and political subdivisions as employers, regardless of size.

Ginsburg rejected the fire district's warning that applying the ADEA to small public entities risks limiting vital public services, such as fire protection. She said for 30 years the Equal Employment Opportunity Commission has consistently interpreted the ADEA as the high court has and that most states prohibit age discrimination by political subdivisions of any size.

In a statement Tuesday, Rosenkranz said:

“I recognize Congress did not express itself very clearly. The resulting regime is incoherent. Small employers—public and private—are exempt from discrimination suits on the basis of race, ethnicity, sex, and religion. And small private employers are exempt from discrimination suits on the basis of age. The one thing no one, including the Supreme Court, has ever explained is why Congress would have purposely singled out public employers for harsh treatment for this one type of discrimination in a statute whose purpose was to put them on equal footing with private employers. We fully expect Congress to fix its drafting error and restore parity to public and private entities in a way that makes sense across all discrimination statutes.”

Stanford Law School's Jeffrey Fisher argued on behalf of the terminated employees. Assistant to the Solicitor General Jonathan Bond also argued in support of the employees.

The Supreme Court's ruling is posted below:

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