Final answer:
The federal law that prohibits age discrimination and applies to employers with at least 20 employees is the Age Discrimination in Employment Act of 1967 (ADEA). The ADEA ensures that individuals aged 40 or older are protected from unfair treatment and discrimination in various aspects of employment.
Step-by-step explanation:
The federal law that prohibits age discrimination and is applicable to employers with at least 20 employees is the Age Discrimination in Employment Act of 1967 (ADEA). This law makes it illegal for employers to discriminate against employees or job applicants based on their age, specifically those who are 40 years old or older.
The ADEA covers various aspects of employment, including hiring, firing, pay, promotions, job assignments, layoff, training, fringe benefits, and other terms and conditions of employment. It ensures that individuals are not treated unfairly or differently due to their age.
For example, an employer cannot refuse to hire someone simply because they are older or fire an employee solely based on their age. Additionally, the ADEA also prohibits policies and practices that have an adverse impact on individuals aged 40 or older, unless they are based on a reasonable factor other than age.