The CBO said the president's budget blueprint would raise the deficit next year by $365 billion, The Hill reported.
The CBO estimate is nearly a mirror opposite of White House reports last month that Obama's budget would reduce deficits by $3.2 trillion during the next 10 years.
The Hill said differences between the two estimates could be traced to different baselines and economic assumptions. One big reason the non-partisan CBO said it expected the deficit increase was that it assumed all Bush-era tax rates would expire at the end of this year.
Obama's budget reflects the continuation of the middle-class tax cuts, something reflected in his budget.
Over 10 years, the CBO estimate said, the Obama budget contains $6.4 trillion in new deficits, which is better than the new deficits of $6.7 trillion White House had predicted.
House Budget Committee Chairman Paul Ryan, R-Wis., who will release his own budget next week, seized on the CBO estimates.
"It confirms the president will not fulfill his promise to cut the deficit in half by the end of his first term," Ryan said. "When it comes to our generation's greatest challenges, the president refuses to take accountability or demonstrate much-needed leadership."