Understanding the Alternative Minimum Tax: What Small Business Owners Need to Know

What is Alternative Minimum Tax?

The Alternative Minimum Tax (AMT) is a parallel tax system in the United States that aims to ensure individuals, including small business owners, pay a minimum amount of federal income tax regardless of deductions, exemptions, or credits that would otherwise significantly reduce their tax liability. It was originally implemented in 1969 to ensure that wealthy taxpayers paying minimal taxes through deductions and loopholes would contribute a fair share to the government’s revenue.

Calculating Alternative Minimum Tax

To determine whether a taxpayer owes Alternative Minimum Tax, they must follow specific calculations. The tax calculation requires adding back certain deductions and adjustments to their regular taxable income. If the AMT liability exceeds the regular income tax liability, the taxpayer is required to pay the higher AMT amount. Here are the essential components of the calculation:

  • Taxable Income – Start with taxable income, which includes wages, salaries, self-employment income, and other taxable earnings.
  • Add-Backs – Certain deductions and exemptions claimed on regular tax returns may need to be added back, like depreciation on certain property, medical expenses, miscellaneous deductions, personal exemptions, and more.
  • AMT Exemption – The AMT exemption is subtracted from the taxable income, which varies based on income levels. For example, the Tax Cuts and Jobs Act of 2017 increased the exemption for individuals and married couples filing jointly.
  • AMT Rates – After applying the exemption, the remaining income is subject to either a 26% or 28% tax rate, depending on the taxpayer’s income level.
  • Compare and Pay – Finally, the taxpayer compares the tax liability resulting from the AMT calculation to their regular income tax liability. If the AMT amount is higher, they must pay the difference.

It is important to note that the AMT applies to both individuals and corporations, albeit with different rules and exemption thresholds. However, the focus of this article is on the AMT in the context of small businesses.

Why Small Business Owners May Be Affected?

The Alternative Minimum Tax can impact small business owners due to the nature of their business and the various deductions and exemptions they may take advantage of. Here are some reasons why small business owners should be aware of the AMT:

  1. Deductible Expenses – Small business owners often have numerous deductible expenses, such as depreciation on business-related assets, equipment, research and development costs, and employee benefits. These deductions can alter their regular taxable income, potentially triggering the AMT.
  2. Tax Preferences – Certain tax preferences, specifically those related to accelerated depreciation methods or tax-exempt bond interest, can become adjustments required by the AMT calculations.
  3. Pass-through Entities – Many small businesses are structured as pass-through entities, such as S corporations, partnerships, or limited liability companies (LLCs). The AMT applies to the individual owners or partners, impacting their personal tax liabilities and potentially reducing the financial benefits of deductions within the business.
  4. Higher Tax Rates – The AMT rates can be higher than regular income tax rates, leading to an increase in the overall tax burden for small business owners subject to this parallel tax system.
  5. Exemption Thresholds – Small business owners need to be mindful of the AMT exemption thresholds. As their income or business grows, they may become more likely to cross these thresholds, increasing their chances of being subject to the AMT.

Understanding the various factors that contribute to AMT liability is crucial for small business owners to effectively plan their finances and evaluate the potential impact on their tax obligations.

Alternative Minimum Tax vs. Regular Income Tax: A Comparison

It is helpful to compare the key differences between the Alternative Minimum Tax and regular income tax. The table below outlines some of the distinctions:

Alternative Minimum Tax (AMT) Regular Income Tax
Tax Calculation Complex calculation involving add-backs, exemptions, and AMT rates Deductions and exemptions significantly reduce taxable income
Tax Rates 26% or 28% for individuals Various tax brackets with progressive rates
Exemptions Varies based on income levels Standard deduction or itemized deductions
Applicability Applies to taxpayers with specific circumstances or higher incomes Applies to all taxpayers

These comparisons highlight the distinct features of each tax system and exemplify why small business owners should pay careful attention to the potential impact of the AMT.


The Alternative Minimum Tax is a parallel tax system designed to ensure individuals, including small business owners, pay a minimum amount of federal income tax. Small business owners need to be aware of the AMT, as the nature of their business and various deductions may influence their tax liability. By understanding the calculation, potential triggers, and differences when compared to regular income tax, small business owners can navigate the complexities of the tax system and make informed financial decisions.