CBO forecast in their June 2017 current law baseline that the U.S. debt held by the public (a partial measure of national debt and the primary measure used by economists) would be 14,656 in January 2018. This excludes any effect of the tax legislation.
The deficit baseline increase of 10,112 is shown in the their analysis of the TCJA as well as the June 2017 baseline. This also excludes the TCJA legislation and is mainly driven by an aging country and higher healthcare expenses per person.
The other source of financing of 757 is shown in the June 2017 baseline.
The TCJA impact is shown in the Senate analysis of the bill, cited here.
The sum of these changes adds to 26,939. Note that this is somewhat different from what is shown in the CBO analysis of the Senate bill, which excludes the other financing shown in the baseline.[1]
English: CBO forecast that the Tax Cuts and Jobs Act would add $1.4 trillion to the debt held by the public over the 2018-2027 period, excluding macroeconomic feedback effects. This is in addition to sizable debt increases already in the June 2017 policy baseline. The ratio of debt to GDP also rises from around 77% GDP to 97% GDP.