And by 2024, the federal debt is estimated to reach 78 percent of the economy, twice the 39 percent average of the past four decades.
The budget office warned that the aging of the population, rising healthcare costs and increasing interest payments on the debt will bring about the return to $1 trillion deficits by 2024 in the absence of legislative changes.
The CBO said cumulative deficits over the next decade will total $7.6 trillion if current laws remain unchanged. That's a drop of $286 billion from the deficit projections of two months ago.
The gross federal debt will rise from approximately $17.7 trillion this year to $27 trillion by the end of the next 10 years. Most of the decline in the deficit for 2014 is due to lower estimates for discretionary spending.
Most of the reduction in ObamaCare subsidies comes from lower technical estimates of the premiums insurers participating in healthcare exchanges will charge.
Affordable Care Act subsides would be $186 billion less over 10 years than previously thought, the CBO said, while Medicare spending would be $98 billion lower.
Updated at 12:10 p.m.