 A credit rating assigned to U.S. sovereign debt is an expression of how likely the assigning CRA thinks it is that the U.S. will pay back its debts.A credit rating assigned to U.S. sovereign debt also influences the interest rates the U.S. will have to pay on its debt; if its debtholders know the debt will be paid back, they do not have to price the chance of default into the interest rate.However, these ratings sometimes measure different things; for instance Moody's considers the expected value of the debt in the event of a default in addition to the probability of default.