The US Supreme Court ruled Monday that the federal Age Discrimination in Employment Act (ADEA) applies to both state and local government, regardless of how many people they employ.

Justice Ruth Bader Ginsburg wrote the opinion for an 8-0 court in answering the question, of whether the “ADEA’s specification (20 or more employees) applies to ‘a person engaged in an industry affecting commerce,’ apply as well to state entities.”

The text of 29 USC §630(b) reads: “The term ’employer’ means a person engaged in an industry affecting commerce who has twenty or more employees. … The term also means (1) any agent of such a person, and (2) a State or political subdivision of a State.” The parties disputed the proper reading of the ADEA following an amendment in 1974. Specifically, “Does ‘also means’ add new categories to the definition of ’employer,’ or does it merely clarify that States and their political subdivisions are a type of ‘person’ included in §630(b)’s first sentence?”

The court held, “§630(b)’s two-sentence delineation, and the expression ‘also means’ at the start of the second sentence, combine to establish separate categories: persons engaged in an industry affecting commerce with 20 or more employees; and States or political subdivisions with no attendant numerosity limitation.