Alternative minimum tax rates are unchanged, but the exemption amounts and phase-out thresholds for the AMT have increased.
The TCJA also modified the alternative minimum tax (AMT). The exemption amounts were increased for 2018 as follows.
These amounts are set to adjust on an annual basis. Along with increased exemption and phase-out limits, the AMT calculation was further simplified by the elimination or reduction of itemized deductions that were traditionally added back to income to determine the AMT. Finally, although AMT rates remain the same, the threshold amounts were adjusted. For 2018 the 26 percent rate applies for income subject to AMT up to $175,000 and 28 percent for income above $175,000.