The budget deficit for Fiscal Year 2013 dropped to $680.3 billion, the government reported Wednesday -- the first time in five years the shortfall has been below $1 trillion.
Both the Obama administrations and congressional Republicans cited their own cost-cutting efforts.
The deficit "is now less than half of what it was when the president took office," said Treasury Secretary Jacob Lew in a statement.
It remains the fifth-largest deficit in history, but the lowest since a $458.6 billion figure in 2008.
Among the reasons: A growing economy, the end of a temporary Social Security tax cut, higher tax rates on wealthy Americans, and the series of across-the-board tax hikes known as sequestration.
Senate Minority Leader Mitch McConnell, R-Ky., cited the bipartisan Budget Control Act of 2011, which set up the sequester.
Since then, "Washington has actually reduced the level of government spending for two years running," McConnell said. "That's the first time this has happened since the Korean War."