The jobless rate, currently at 5 percent, is expected to average 5.1 percent this year, but rise to about 5.3 percent by the end of 2008, around the time voters in November will pick a new president and decide whether Democrats continue their majority in the House and Senate.
CBO said it sees an average 5.4 percent unemployment rate next year and an average 4.9 percent a year in 2010-13.
CBO envisions a $198 billion budget deficit in fiscal 2009 and sees the deficit rising to $241 billion in 2010.
CBO, which bases its estimates on existing law, forecast a fiscal 2011 deficit of $117 billion and a budget surplus of $87 billion in 2012. But that assumes President Bush's 2001 and 2003 tax cuts expire at the end of 2010 and that a temporary measure to fix the alternative minimum tax also expires.
In August, CBO predicted the fiscal 2008 budget deficit would be $155 billion. That was before the pinch of an unfolding economic slowdown became apparent.
CBO said it sees interest rates on Treasury securities remaining low this year and increasing in 2009 as the economy emerges from its current difficulties.
CBO said the weak U.S. dollar and relative economic strength of U.S. trading partners should boost exports and help offset the sluggishness in domestic demand.
It also said emerging economies have become increasingly less dependent on U.S. demand to fuel their economies and as a result have become less vulnerable to slowdowns in the U.S. economy.
Consumer spending, CBO said, is likely to fall off, curtailed by a drop in housing wealth (home equity), increased costs for borrowing, the high price of oil and slower growth of real income.