Statutory Individual Income Tax Rates

Statutory individual income tax rates, also referred to as "statutory marginal tax rates," are the rates of tax applicable to the last (marginal) increment of taxable income.

Statutory rates play an important role in determining the real marginal tax rates, which affect taxpayers' economic behavior.

Developments since enactment of the Tax Reform Act of 1986 (TRA86; P.L. 99-514) are the most relevant to the current state of affairs.

Since then, the Omnibus Budget Reconciliation Act of 1990 (OBRA90; P.L. 101-508), the Omnibus Budget Reconciliation Act of 1993 (OBRA93; P.L. 103-66), and the Economic Growth and Tax Relief Reconciliation Act of 2001 (EGTRRA; P.L. 107-16) and its extensions all changed the marginal income tax rate structure.

Under current law, upon expiration of tax cuts enacted in 2001-2007, the rate structure will revert in 2011 to the one set by OBRA93.The six marginal income tax rates for 2008 are 10%, 15%, 25%, 28%, 33%, and 35%.

Specific types of income, such as capital gains, may be subject to different sets of marginal tax rates.

Alternative minimum tax system (AMT), a parallel tax system which has recently garnered considerable attention, also has a different set of parameters.

Since 1981, Congress established and expanded, with slight modifications, the policy of tax indexation.

Tax indexation helps prevent automatic tax increases and unintended changes in the distribution of the tax burden due to inflation.

Under current law, many key components of the tax structure are indexed for inflation.

Such components include the tax rate brackets, the personal exemptions and their phase-out thresholds, standard deductions, the itemised deduction limitation threshold, and others.

Not all elements of the tax system, however, are currently adjusted for inflation.

One of the examples is the AMT. This book summarises information about the tax brackets and other key elements of the tax system that determine taxpayer's statutory marginal tax rate.

Such elements include tax brackets, exemptions, standard deductions, etc.