替代最小赋税
替代最小赋税税法条款保证个人和公司会付一部分所得税，不管他们有多少扣抵或信用额度。在AMT之下，特定的金钱一般不得被看为应扣税的所得，比如一般为可抵税所得的总合，或者是免税债券的所得，全将被看为是缴税的。替代性最低税是基于防止高收入个人利用税收优惠项目避税的目的而做出的一种税收安排
个人分别按正常收入和AMT收入计算个人所得税，假使前者税额好于后者税额，按前者税额纳税，假使前者税额差于后者税额，除交纳前者税额外，还应交纳两者税额之间的差额即AMT税额。AMT的原理就是把税收优惠项目纳人到个人所得税的税基当中。美国的联邦个人所得税就是按调整后的个人所得加之税收优惠项目减去分项扣除项目及税收豁免后再乘以AMT适用税率得出一个税额，这个税额胜过正常收入计算出来的税额部分就是纳税人应交的AMT税额。 A tax calculation that adds certain tax pference items back into adjusted gross income. Alternative minimum tax (AMT) uses a separate set of rules to calculate taxable income after allowed deductions. Preferential deductions are added back, and then the AMT exemption is subtracted to get the AMT taxable income (AMTI). AMTI is then taxed at the current rate schedule to get tentative minimum tax (TMT). If TMT is higher than the regular tax liability for the year, the regular tax and the amount by which the TMT exceeds the regular tax are paid (i.e. the taxpayer pays the full TMT). AMT is designed to pvent taxpayers from escaping their fair share of tax liability through certain tax breaks, although the structure is rife with controversy as it is not indexed to inflation or tax cuts. This causes a condition known as "bracket creep", whereby upper-middle-income taxpayers are becoming subject to this tax. In 2006, the IRS National Taxpayer Advocate reported that the AMT often punishes taxpayers for having children or living in high-tax states.