For the last fiscal year, the federal budget deficit was about $800 billion, or about 4 percent of GDP. This is an unusually high deficit for this stage of the business cycle, when ideally we should be paying down debt, at least as a percent of GDP.
The Republican corporate tax cut is mostly to blame. Corporate tax revenues fell by $92 billion or 31 percent in FY 2018 (the government fiscal year ending runs from October through September).
Total revenues grew by 3.8 percent. The largest sources of federal revenues in 2018 were individual income taxes ($1,683 billion) and and payroll taxes ($1,170 billion). By comparison, corporate income taxes in 2018 were only about $205 billion.
On the outlay side, Social Security benefits rose by 4.6 percent; Medicare costs by 2.7 percent; and Medicaid outlays by 3.9 percent. (These are the numbers in the adjacent table that are adjusted for timing shifts, such as when the payment date falls on weekend or holiday.)
The subtotal for the largest mandatory spending programs (commonly referred to as social benefit programs or entitlements) grew by 3.8 percent, in line with overall revenue growth.
However, spending for the Department of Defense grew by 6.4 percent, and outlays for interest on the public debt grew by a whopping $62 billion or nearly 20 percent. Interest costs are now nearly as high ($371 billion) as federal spending for Medicaid ($389 billion). Interest costs have increased because of the higher debt load due to deficits and also due to higher interest rates in recent months.
Here is a link to the CBO monthly budget report: www.cbo.gov/...