First, it seems like a very poor design for me to have to respond 'Yes' to whether I made charitable contributions to 30% charities to get to a screen that would allow me to designate other charitable contributions to be 100% deductible, when in fact I had not given to any 30% charities. But I did as you said and designated the charities I had given to in 2020 to be 100% charities, all of which were qualified to be designated that way. What happened surprised me. I expected to get that charitable deduction, plus the other deductions I was entitled to, applied against my AGI. This amount would have been below my AGI. But instead I came up with a total deduction that was greater than my AGI. It appears I had carryover charitable contributions from previous years that were allowed to also be deducted at 100%. That got me up to a value equal to my AGI and then I had the exact amount of my other deductions added to that, so all my deductions were greater than my AGI. My taxable income on line 15 of my 1040SR was 0. But on line 23 of the 1040SR, labeled as other taxes, there was an amount entered. This came from computations made on form 8960 labeled as 'Net Investment Income Tax-Individuals, Estates and Trusts'. The final amount of the tax computed there was also entered onto a form labeled 'Additional Taxes'. I am not sure I agree with this approach. I am not sure it was legitimate to apply carryover charitable contributions the way they were to this tax year, and am concerned by doing things that way that I lose the ability to carryover that amount for future years, especially in light of the fact I was taxed a substantial amount of 'Additional Taxes'. Could you please comment?
