turbotax standard deduction

turbo tax file tax 发现一个问题，大家注意 我是married filling jointly turbo tax会default 用standard deduction,因为我的mortgage interest + 10,000(state/local tax cap) < 25900(standard deduction for joint filling) 但是如果自己硬改成itemize，其实退税会多一百多。 查了一下是因为3.8% 的 net investment income tax,如果是itemize deductin，有1万块deduction。所以差出380。如果standard deduction 和itemize deduction只差一点点，turbo tax并不会把这380算进去。 我的税比较简单，但是看来turbo tax真的挺傻的，大家要自己manually改一下option多检查

I thought net investment income tax is only related to your income level, no $10,000 deduction? Here's how it works: Based on a tax return calculation, a 3.8% surtax applies to the lesser of (1) your net investment income or (2) the amount by which modified adjusted gross income (MAGI) exceeds an annual threshold of $200,000 for single filers and $250,000 for couples filing jointly.