1Social Insurance Taxes consist mainly of payroll taxes, which are primarily taxes for Social Security (called Old-Age, Survivors, and Disability Insurance, or OASDI) and Medicare's Hospital Insurance (HI). A small share of social insurance tax revenues comes from unemployment insurance taxes and contributions to other federal retirement programs.
2Nearly all excise taxes fall into 5 major categories: highway, airport, telephone, alcohol, and tobacco taxes. Almost half of all excise receipts are earmarked by law to The Highway Trust Fund and they come primarily from taxes on gasoline and diesel fuel. The CBO now aggregates excise taxes, estate and gift taxes, and customs duties under “Other.” The breakdown, however, is still available.
3Through FFY 2005 this line was called "International" by the CBO. In FFY 2006, they changed the title of the line to "Nondefense" and "Domestic" was removed.
4Income support includes unemployment compensation, supplemental security income, earned income and child tax credits, food stamps, family support, child nutrition, and foster care.
5Net interest includes interest paid on Treasury securities and other interest that the government pays (for example, on late refunds issued by the Internal Revenue Service) minus interest that the government collects from various sources (such as commercial banks, where Treasury tax and loan accounts are maintained.) Net interest is determined by the size and composition of the government's debt, annual budget deficits or surpluses, and market interest rates.
6Offsetting receipts include Medicare premiums and employers' share of employee retirement, as well as federal pension programs, receipts from auctions and leasing, usert fees, etc. However, the largest amounts are from Medicare premiums and employers' share of employee retirement.
7These numbers do not agree with those published by the U.S. Bureau of Public Debt. This is because the Bureau of Public Debt reports the face value of all debt outstanding. However, some of the bonds sold have interest rates that are indexed to inflation. Therefore, the CBO adjusts the public debt annually to reflect the current market value.
8Through FFY 2005 these numbers only are from the U.S. Bureau of Public Debt as they are not published by the Congressional Budget Office. In FFY 2006 the CBO began reporting Intergovernmental Debt, but stopped publishing it in 2010. In 2010 and after, the Intergovernmental Debt amount is from the Bureau of Public Debt.
9These numbers do not agree with those published by the U.S. Bureau of Economic Analysis. According to the Congressional Budget Office, its number is calculated from seasonally adjusted quarterly national income and product account data from the Bureau of Economic Analysis. This may or may not explain the difference.
Source: Congressional Budget Office