Ask you local Congresscritter. And then ask them why Congress does not prefund...or any other company.
I asked another individual on this board the question, not you. But, you had to stick your nose in it.
Yes, companies do pre-fund certain benefits. Most large companies pre-fund their paid vacation benefits. This is a large benefit that has to be dealt with ahead of time. It seems clear that you are not aware of how private companies actually operate.
Again, do your own research.