This is complete misinformation perpetuated by people who don't understand accounting. They aren't prepaying the future retirement benefits. They need to have retirement fund equal to the PRESENT value of future payments to retirees. In other words, the future payments are discounted back by the expected rate of the return of the retirement plan. This is how every single defined benefit retirement plan in the country works. I don't know if 75 years is typical or not but once you go beyond the 30 years the extra years hardly add much to the present value anyway. Since the post office expects to operate in perpetuity it makes sense that have fund to allow for that. If the post office was allowed to under fund it's pension program it could end up putting taxpayers on the hook later on.