The ADEA prohibits employers from arbitrarily discharging, demoting, refusing to promote or refusing to hire individuals based solely on age.  The Act also extends to discrimination in compensation terms, conditions or benefits of employment, as well as advertisements for positions.  Employers cannot force employees into early retirement.  The ADEA protects employees over the age of 40.  The ADEA also prohibits preferential treatment because of age for people under 40.