The annual net interest payments on the Federal debt is $255 billion. Since the Government receipts are over $3,000 billion per year, there is no chance of any default on US debt obligations. That tax revenue works out to be about $250 billion of tax revenue per month and interest payments are about $20 billion per month. All entitlement spending is another $125 billion per month. That's $145 billion of absolutely essential spending per month versus $250 billion revenue. So all Medicare and Social Security checks can go out. All interest payments can be made---easily.