Avoid AMT

Avoid the Alternative Minimum Tax

But the tax was not permanently indexed for inflation until 2013, and it had become a de facto "flat tax" for upper-middle income taxpayers. The 20 I 7 Tax Cuts and Jobs Act raised the threshold for qualifying but did not remove the AMT entirely.
The AMT system starts with regular taxable income then adds "preference items."

Alternative minimum tax ("AMT") is a parallel tax designed to prevent "the rich" from using regular deductions to avoid tax entirely. In 2009, it hit 4.5 million taxpayers nationwide, primarily in states with high income and property taxes.

These include:

Medical expenses between 7.5% and 10% of AGI
State and local taxes deducted on Schedule A
Home equity interest not used to buy, build, or improve your home
Investment interest figured according to special rules
A portion of post-1986 accelerated depreciation
Gains from incentive stock options ("ISOs")
Interest from most "private activity" municipal bonds

Once you have determined AMT income, subtract an exemption of$109,400 (joint filers), $70,300 (single filers), or $54,700 (separate filers). These exemptions phase out by 25 cents for every dollar of AMTI above $1,000,000 for joint filers and $500,000 for other filers. The tax itself is 26% of AMTI up to $95,750 ($191,500 for joint filers)plus 28% of AMTI above those thresholds (2018).

Here are several ways to help avoid the AMT:

Do not prepay state income and property taxes in years you are subject to the AMT.
Avoid private activity municipal bonds.
Defer exercising ISOs where it makes investment sense.
Schedule business equipment purchases when you can use your full depreciation deductions.
If your employer reimburses business expenses, make sure you have an “accountable" plan to keep them off your return.
Defer recognizing capital gains. These gains are taxed at 20% for AMT-the same rate as for regular tax- however, they increase other taxable income subject to the AMT.