Tax collection statistics.
Collections before refunds by type of return, fiscal year 2010.
Individual income tax (49.9%).
Employment taxes (35.3%).
Corporate income taxes (11.9%).
Excise taxes (2.0%).
Estate taxes (0.7%).
Other (0.2%).
For fiscal year 2009, the U.S. Congress appropriated spending of approximately $12.624 billions of "discretionary budget authority" to operate the Department of the Treasury, of which $11.522 billion was allocated to the IRS. The projected estimate of the budget for the IRS for fiscal year 2011 was $12.633 billion. By contrast, during Fiscal Year (FY) 2006, the IRS collected more than $2.2 trillion in tax (net of refunds), about 44 percent of which was attributable to the individual income tax. This is partially due to the nature of the individual income tax category, containing taxes collected from working class, small business, self-employed, and capital gains. The top 5% of income earners pay 38.284% of the federal tax collected.
As of 2007, the agency estimates that the United States Treasury is owed $354 billion more than the amount the IRS collects. This is known as the tax gap.
The gross tax gap is the amount of true tax liability that is not paid voluntarily and timely. For years 2008-2010, the estimated gross tax gap was $458 billion. The net tax gap is the gross tax gap less tax that will be subsequently collected, either paid voluntarily or as the result of IRS administrative and enforcement activities; it is the portion of the gross tax gap that will not be paid. It is estimated that $52 billion of the gross tax gap was eventually collected resulting in a net tax gap of $406 billion.
In 2011, 234 million tax returns were filed allowing the IRS to collect $2.4 trillion out of which $384 billion were attributed to mistake or fraud.