The basic structure of the current alternative minimum tax (AMT) is primarily the result of amendments by the 1986 Tax Reform Act (86 Act).  The AMT system is a parallel tax system, requiring the application of the AMT rates to a broader tax base than the regular taxable income.  The taxpayer pays the greater of the regular income tax or the tentative AMT.  The tentative AMT is the alternative minimum tax base (see formula below) multiplied by the alternative minimum tax rates, less the AMT foreign tax credit.