Unlike a private family, the nation need never pay off its debt. Instead, each time the principal is due, the U.S. Treasury can simply ‘roll it over’ by floating more debt. Indeed, this is precisely what the Treasury does.
Since 1957.
Also, the U.S. government is completely different from a household, starting with the government’s basic ability to tax and to print money. And that means it’s often misleading to use household comparisons as easy policy guides.