“discrimination in employment”

prohibited job discrimination based on age. The law was specifically designed to protect job applicants over 40 years of age. It applies to federal, state, and city governments and to private businesses that have more than 20 employees and engage in interstate commerce. Some exceptions are allowed in the case of law enforcement and fire-fighting personnel, and in those instances in which the employer can offer convincing evidence that age is a bona fide job criterion.