I'm trying to figure out at what point AMT might hurt me, because I just received from stock options from my employer and am considering the benefit of exercising. I worked through form 6251, but I want to make sure I'm understanding it correctly. I get the basic idea: you recalculate your taxable income without some deductions plus the value of exercised options, then multiply that by the AMT rate to get your theoretical AMT amount. If AMT is greater than your income tax you pay it.
Since I only deduct mortgage interest, charity, medical expenses, and local taxes; line 2a on 6251 is basically the sum of my medical and local taxes (IE - I keep charitable and mortgage interest deductions [exclusive of any HELOC]).
Secondly, line 10 of 6251 says:
Add Form 1040 or 1040-SR, line 16 (minus any tax from Form 4972), and Schedule 2 (Form 1040), line 2
This is the amount used as your federal tax amount, but it excludes any child tax credit. So are theoretical AMT taxes are compared to your federal taxes before the child tax credit?
On top of that, when the TCJA expires in 2026 does that impact the child tax credit being included/excluded from the federal tax/AMT comparison?