Last week, the Congressional Budget Office issued its first estimate of how the U.S. national debt would change over the next 10 years as a result of the tax cut legislation now making its way through Congress.

That estimate came in the form of a November 8, 2017 letter from CBO Director Keith Hall to Rep. Richard Neal (D-MA), ranking member of the House Ways and Means Committee, in which Hall indicated that the CBO anticipated the publicly held portion of the national debt in the year 2027 would increase from 91.2% of GDP to 97.1% of GDP in that year if the House of Representatives bill H.R. 1, the Tax Cuts and Jobs Act, in its current form were to become law.

However, the publicly held portion of the national debt is just a fraction of the U.S. government’s total public debt outstanding, so those percentages don’t provide the full picture of how the U.S. national debt would change under H.R. 1.

To find out what the impact might be to the full national debt, we took the CBO’s baseline projections of the gross national debt for the years 2017 through 2027 as a percentage of GDP and added in the additional portion that the CBO’s director indicated the national debt would grow over that time. The following chart shows those results, along with historical data going back to 1967, where we’ve indicated the level of the national debt as a percentage of GDP at the beginning of each elected U.S. President’s term in office to provide some historical context.

Because the effect of the tax cuts wouldn’t show up until the U.S. government’s 2018 fiscal year, there would be no change in the CBO’s projections through 2017. Beginning in 2018 however, there is a gap that grows from year to year for the CBO’s different projections for the national debt.

Without any tax cuts, the U.S. national debt was projected to grow from 109.2% of GDP in 2017 up to 116.7% of GDP in 2027. Under the House’s version of the tax cut bill, the national debt would be projected to grow up to 122.6% under the CBO’s assumptions. This result also assumes that the proposed tax cuts would have no impact on the growth of GDP during the next decade.

At this writing, the CBO has not yet evaluated the Senate’s version of the tax cut bill.

Coincidentally, the CBO projects that the rate of growth of the total national debt from 2017 through 2027 with the tax cuts outlined in H.R. 1 would be about the same as was realized during President Obama’s second term in office.