As a non-Acronymian myself, I believe that it means that the US government has decided that the USA as a corporation — which is what it is — has been declared bankrupt, or something to that effect. That means that no more money will be going to the government's ongoing affairs until the situation has been resolved.
Of course, the Deep State has enough funds set aside for situations like this, so you can count on the mass surveillance and other nefarious operations to carry on unabatedly during this time.