At the end of last year, the United States government has reached the legal limit for how much money it can borrow, commonly known as the "debt ceiling", which is just shy of $16.4 trillion. This means that the Treasury is no longer allowed to borrow any money (except to roll over existing debt) to finance government operations and the resulting $1.1 trillion annual deficit.
The Treasury has been able to cope so far by temporarily suspending investments into pension plans, but that measure can only last for a couple of months. After this time, unless Congress has agreed to increase the debt ceiling, the government will have to find another way to close the gap.
Many ideas have been floated around. Many of them are ridiculous, and some of them would open the government to a legal challenge of some sort. But they're worth at least exploring.
