In the 1992 case Hazen Paper Company v. Walter F. Biggins, the U.S. Supreme Court ruled that an employer's decision to terminate an employee shortly before their pension vested did not constitute age discrimination under the Age Discrimination in Employment Act (ADEA). The plaintiff, Walter F. Biggins, was fired by his employer, Hazen Paper Company just weeks before he would have been eligible for a full pension after ten years of service with the company. He argued that this action was motivated by age discrimination because older workers are more likely to be close to vesting their pensions than younger ones. The court held that while firing someone due to proximity to vesting might be illegal under other laws or contractual agreements related specifically to pensions and benefits, it does not violate ADEA unless there is evidence showing that age itself factored into the termination decision - which wasn't proven in this case.

In the dissenting opinion for Hazen Paper Company v. Walter F. Biggins, Justice Blackmun argued that age and years of service are so closely correlated that it is impossible to distinguish between them in many cases. He contended that firing an older employee because they have worked long enough to earn a pension should be considered discrimination based on age, as younger employees would not face this same risk due to their shorter tenure at the company. Therefore, he disagreed with the majority's view that such actions do not violate the Age Discrimination in Employment Act (ADEA). Furthermore, he expressed concern about employers being able to easily circumvent anti-discrimination laws by citing reasons related to length of service rather than directly mentioning age.