The new figure is slightly less than 2014's deficit of $483 billion. In February, the administration predicted a deficit of $583 billion.
During Obama's first term, deficits topped $1 trillion each year. That reflected a severe financial crisis and the worst recession since the Great Depression of the 1930s.
But as the economy has recovered, revenues have gone up. The rates of inflation for expensive health care programs have fallen and annual agency budgets have remained tight, contributing to the improved deficit picture.
The 2015 budget year officially ends on Sept. 30.