The budget deficit increased from $779 billion in FY2018 to $984 billion FY2019, up $205 billion or 26%. The budget deficit increased from $666 billion in FY2017 to $779 billion in FY2018, an increase of $113 billion or 17.0%. The 2019 deficit was an estimated 4.7% GDP, up from 3.9% GDP in 2018 and 3.5% GDP in 2017. The historical average deficit is 2.9% GDP. During January 2017, just prior to President Trump's inauguration, CBO forecast that FY2019 budget deficit would be $610 billion if laws in place at that time remained in place. The $984 billion actual results represents a $374 billion or 61% increase versus that forecast, driven mainly by tax cuts and additional spending. Similarly, the FY 2018 budget deficit of $779 billion was a $292 billion or 60% increase versus that forecast.