The last-minute debt ceiling deal Congress is racing to enact would reduce deficits by at least $2.1 trillion over 10 years.

That's the verdict from the all-important nonpartisan Congressional Budget Office, which is the official scorekeeper for all legislation.

The numbers the CBO reported are largely in line with the estimates congressional leaders and the White House reported Sunday night in announcing the deal.

In exchange for the debt reduction laid out by the bill, the debt ceiling will be allowed to increase by between $2.1 trillion and $2.4 trillion. That would cover Treasury's borrowing needs until 2013.

The CBO estimates that the Budget Control Act of 2011 would initially reduce deficits by $917 billion primarily by imposing caps on discretionary spending. Read More