The pre-funding requirement is set for 75 years into the future. Thus, they have to forecast how many employees they expect that far into the future, and then f

The pre-funding requirement is set for 75 years into the future. Thus, they have to forecast how many employees they expect that far into the future, and then fund this pension for employees who are not even born yet. It's a massive burden because they have had to set aside a significant amount of money that could be used to improve their services. No other federal department has the same requirement, and there are significant savings for pay-as-you-go, since there is no guarantee just how many employees they'll need in the future given unknown technological advancements. Also, the USPS is a government corporation, which is bound and managed by congress, but receives $0 from the tax payers each year. They are required to make their own revenue, but the profits are controlled by congress.