Which federal legislation protects employees aged 40 and older from discrimination?

The Age Discrimination in Employment Act (ADEA) is the federal legislation designed specifically to protect employees who are aged 40 and older from discrimination in the workplace. This act prohibits employers from making employment decisions based on an individual's age, ensuring that older workers have the same opportunities as their younger colleagues. The ADEA applies to various aspects of employment, including hiring, promotion, wages, and other terms and conditions of employment.

In contrast, the Employee Retirement Income Security Act (ERISA) focuses on the regulation of employee benefit plans and does not address age discrimination specifically. The Americans with Disabilities Act (ADA) aims to protect individuals with disabilities from discrimination in various areas, including employment, but it is unrelated to age discrimination. Similarly, the Family and Medical Leave Act (FMLA) provides certain employees with the right to take unpaid leave for family and medical reasons, and while it offers important protections, it does not deal with age discrimination. Thus, the ADEA is the correct answer as it directly targets the discrimination issue affecting older employees.