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Updated December 4, 2017
Tax Reform: The Alternative Minimum Tax
The U.S. federal income tax has both a personal and a 
Individual AMT 
corporate alternative minimum tax (AMT). Both the 
The modern individual AMT originated with the Revenue 
corporate and individual AMTs operate alongside the 
Act of 1978 (P.L. 95-600) and operated in tandem with an 
regular income tax. They require taxpayers to calculate 
existing add-on minimum tax prior to its repeal in 1982. 
their liability twice—once under the rules for the regular 
Table 2 details selected key individual AMT parameters.  
income tax and once under the AMT rules—and then pay 
the higher amount. Minimum taxes increase tax payments 
Table 2. Selected Individual AMT Parameters, 2017 
from taxpayers who, under the rules of the regular tax 
system, pay too little tax relative to a standard measure of 
Single/ 
Married 
their income.  
Head of 
Filing 
Married Filing 
 
Household 
Jointly 
Separately 
Corporate AMT 
Exemption 
$54,300 
$84,500 
$42,250 
The corporate AMT originated with the Tax Reform Act of 
1986 (P.L. 99-514), which eliminated an “add-on” 
28% bracket 
187,800 
187,800 
93,900 
minimum tax imposed on corporations previously. The 
threshold 
corporate AMT is a flat 20% tax imposed on a 
Source: Internal Revenue Code. 
corporation’s alternative minimum taxable income less an 
exemption amount. A corporation’s alternative minimum 
The individual AMT tax base is broader than the regular 
taxable income is the corporation’s taxable income 
income tax base and starts with regular taxable income and 
determined with certain adjustments (primarily related to 
adds back various deductions, including personal 
depreciation) and increased by the disallowance of a 
exemptions and the deduction for state and local taxes. In 
number of preference items, primarily related to extraction 
addition, the individual AMT restricts the use of selected 
activities (depletion and expensing of intangible drilling 
tax preferences, such as tax-exempt interest from qualified 
costs) and the special deduction for Blue Cross and Blue 
private activity bonds and accelerated depreciation. 
Shield companies. In 2013, the most recent year available, 
Taxpayers deduct the AMT exemption amount to determine 
the adjustments reduced AMT taxable income relative to 
their AMT taxable income. To this measure of income 
regular taxable income, while the preference items resulted 
taxpayers apply a two-tier rate structure with rates of 26% 
in greater AMT taxable income. A corporation must pay the 
and 28% to determine their personal AMT liability; they 
AMT if the computation of tax under the AMT is greater 
pay the higher of their regular or AMT liability. 
than the computation of its tax under the regular tax. The 
corporate AMT serves to limit the use of tax preferences to 
Individual AMT Revenue 
reduce tax on retained, as well as distributed, earnings. The 
As shown in
 Table 3 the individual AMT revenues were 
corporate AMT allows a credit for prior year corporate 
between 1.5% and 2% of individual tax receipts in 2004 
AMT payments and also exempts small business 
and 2014. In those years, tax filers paying the individual 
corporations (with gross receipts averaging less than $7.5 
AMT were 2.3% (in 2004) and 2.9% (in 2014) of all tax 
million per year) entirely. 
filers. 
Corporate AMT Revenue 
Table 3. Selected Individual Income Tax Statistics 
As shown in
 Table 1, the corporate AMT revenues were 
roughly 1% of corporate tax receipts in both 2003 and 
 
2004 
2014 
2013. In these years, firms paying the corporate AMT were 
less than 2% of all corporations. 
Number of Returns 
132,226,042 
148,606,578 
Number of AMT 
3,096,299 
4,277,624 
Table 1. Selected Corporate Income Tax Statistics 
Returns 
 
2003 
2013 
Total Tax Liability 
$884,342,703 
$1,432,797,923 
Before Credits 
Number of Returns 
5,401,237 
5,887,804 
AMT Liability 
$13,029,239 
$28,645,905 
Number of AMT Returns 
9,564 
10,222 
Source: Department of the Treasury, Internal Revenue Service, 
Total Tax Liability (‘000s) 
$241,275,165 
$437,372,463 
Individual Income Tax Complete Book, 2004 and 2014, Table 1.4. 
AMT Liability (‘000s) 
$2,298,776 
$4,197,924 
Due to its design, a taxpayer is more likely to face the 
Source: Department of the Treasury, Internal Revenue Service, 
individual AMT if they reside in a “high tax” state or if they 
Corporation Complete Book, 2003 and 2013, Table 2 and Table 23. 
have children. Also, since the graduated regular income tax 
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Tax Reform: The Alternative Minimum Tax 
rates extend higher than the top AMT tax rate, nearly 60% 
Given that the corporate and individual AMTs both 
of taxpayers with incomes between $200,000 and $1 
disallow selected tax preferences (removing their ability to 
million face the individual AMT, making this group of 
influence choices), they could improve the economic 
taxpayers more than three times as likely to pay the 
efficiency of the federal tax system. However, affected 
individual AMT as taxpayers with income greater than $1 
corporations and individuals face higher marginal tax rates 
million. 
as a result of the AMT, which is likely to influence 
economic decisions. Overall, it is not clear which effect is 
Economic Analysis of the AMTs 
larger. The overall effect depends upon taxpayers’ 
Ideally, the regular tax system would fully address the 
awareness of how the AMT applies to them, taxpayers’ 
trade-offs between equity, efficiency, and simplicity, along 
responsiveness to these incentives, and other factors. 
with the need to raise revenue. However, the existence of 
the AMT—a parallel tax system—suggests that the regular 
Simplicity and Transparency 
tax system does not achieve the desired balance under all 
The AMT reduces both the simplicity and transparency of 
circumstances. 
the tax system. The need to calculate taxes twice for many 
corporate and individual taxpayers decreases the simplicity 
Equity 
of the overall tax system. The AMT is also likely to reduce 
The AMT was originally motivated by a rough idea of 
the transparency of the federal tax system, as corporations 
vertical equity: high-income taxpayers and profitable 
and individuals may have greater difficulty in determining 
corporations should be required to pay at least some income 
the tax consequences of certain choices. 
taxes each year. The AMT attempts to achieve this by 
denying selected tax benefits to certain taxpayers, which 
Recent Proposals 
may improve the overall equity of the tax system. 
The House-passed version of the “Tax Cuts and Jobs Act” 
would eliminate both the corporate and individual AMT 
The design of the corporate and individual AMTs may raise 
beginning in 2018. The Senate-passed version, however, 
concerns about horizontal equity, which requires that 
would retain the corporate AMT and modify the individual 
taxpayers with similar abilities to pay should pay similar 
AMT (by raising the AMT exemption levels). The 
taxes. The regular tax system, arguably, addresses this 
modification of the individual AMT would sunset at the end 
concern by allowing taxpayers with certain characteristics 
of 2025. 
to pay less in taxes than otherwise equivalent taxpayers. 
The AMTs retain some of these preferences and disallow 
The House “Better Way” tax reform blueprint proposed to 
others. In cases where the AMT treatment differs from the 
eliminate both the corporate and individual AMTs. The 
regular income tax, ability-to-pay arguments may not be 
Urban-Brookings Tax Policy Center (TPC) estimated that 
taken into account and horizontal equity may be reduced as 
repealing the individual AMT would reduce federal revenue 
a result. This may reduce the overall equity of the tax 
by $427.3 billion over 10 years. The TPC did not separately 
system. 
estimate the revenue effects of repealing the corporate 
AMT.  
Efficiency 
A tax system is considered economically efficient if it does 
This In Focus is part of a series of short CRS products on 
not distort the choices that would be made in its absence. 
tax reform. For more information, congressional clients 
No feasible tax system is fully efficient. This is because the 
may visit the “Taxes, Budget, & the Economy” Issue Area 
structural components of a feasible tax system—such as tax 
Page at www.crs.gov. 
rates, deductions, and credits—influence decisions that 
taxpayers make. 
Donald J. Marples, Specialist in Public Finance   
IF10705
 
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Tax Reform: The Alternative Minimum Tax 
 
 
 
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