On November 6, 2018, in the case of Mount Lemmon Fire District v. Guido, the U.S. Supreme Court ruled that the Age Discrimination in Employment Act (ADEA) applies to state and local governments regardless of the number of employees they have.  This contrasts with private employers, who must have at least 20 employees to be covered under the ADEA.

The ADEA protects people from “arbitrary age discrimination” in employment.  In the Mount Lemmon case, a fire district faced with financial difficulties fired its two oldest firemen, age 46 and 54, who then brought the suit.  The district court ruled against the firemen, holding that the ADEA did not cover the fire district because it had less than 20 employees.  Now that the Supreme Court has reversed that ruling, the case is free to proceed to trial.