Section 201 of the Congressional Accountability Act (CAA) provides that all personnel actions affecting covered employees shall be free from age discrimination for those forty years old or older. This includes hiring, discharge, promotion, pay, benefits, reassignment, and other personnel actions affecting the terms, conditions, and privileges of employment.

Proving motivation depends on the facts of a particular case. For example, placing a phrase like "age 25-50," "young," or "college student" in a help-wanted notice or advertisement may be evidence of a possible discriminatory motive. Furthermore, a covered employee must prove that he or she was treated differently from others in similar circumstances, and that age was a motivating factor in that treatment.

A covered employee over forty may also assert that he or she is harassed because of age. Insults, jokes, slurs, or other conduct relating to age may be unlawful if they create a hostile work environment or interfere with an individual's work performance.

The CAA only protects individuals who are at least forty years old against discrimination; individuals younger than forty are not protected. Bona fide seniority or merit systems may be used so long as they are not instituted to discriminate on the basis of age.