I am struggling to figure out how Turbo Tax calculated the self-employed health insurance deduction on line 17 of schedule 1. I assumed it would be what we actually paid for marketplace coverage plus what I entered for dental and vision premiums we also paid. But that's not it. It's more than our marketplace premiums but less than the total of premiums for healthcare, dental and vision premiums. Thanks!
It is pretty complicated, but your premium tax credit is factored into how much self-employed health insurance you can deduct. The reason for this is to prevent you from getting a benefit from a premium tax credit that is based on your health insurance premiums while also deducting the health insurance premiums, thus potentially giving you a double benefit.
There are two methods of calculating your self-employed health insurance deduction, the simplified calculation method and the iterative calculation method. This article explains how they work, the procedures are to voluminous to enter on this message board: SE health ins ded and premium tax credit
And Self-employed health insurance deduction goes on Form 1040 Schedule 1 line 17 then to 1040 line 10, as long as the expense is not greater than your net self-employment income. If it does exceed your net self-employment income it gets split automatically. An amount equal to your net self-employment income goes on Form 1040 Schedule 1 line 17 and the remainder gets added in to medical expenses on Schedule A.