First, the Congressional Budget Office (CBO 2002b) now projects a 10-year baseline surplus of $1 trillion. These projections also show that outside the Social Security Trust Funds, the budget has a deficit of $1.5 trillion over the next 10 years; omitting the Medicare Hospital Insurance Trust Fund as well, the deficit amounts to $1.9 trillion. These figures represent astonishingly large declines from the forecasts made just 20 months ago. The projected outcome for the fixed time period of 2002 to 2010 deteriorated on a unified budget basis from a surplus of $4.7 trillion in January 2001 to essentially zero ($13 billion) in August 2002. The projected outcome for 2002 alone changed by $470 billion, from a surplus of $313 billion in January 2001 to a deficit of $157 billion in August 2002.
The Vanishing Budget Surplus: Interpreting CBO's New Projections and Fiscal Prospects - Brookings Institution