My brother worked for 12 years at a medium salary as an insurance Exec, and then he finally had one really great year of stock options, bonuses, dividends and interest.
He had pre-estimated his taxes and mailed them in quarterly, using the standard provisions and tax table. In doing this, he had sent in about $65,000 in taxes, and thought he was done.
He was sick to hear from his accountant that the Alternative Minimum Tax applied to him that year, and he owed another $20,000 or so.
He was struggling to put his three kids through college at a state university, and this was really devastating news.
The AMT in its current form is a travesty and needs to be abolished. Trump is considering it.