IRS FAQ 32 provides that the self-employed health insurance deduction reduces QBI:
The final regulations add additional clarity in § 1.199A-3(b)(1)(vi), which provides that generally deductions attributable to a trade or business are taken into account for purposes of computing QBI to the extent that the requirements of section 199A and § 1.199A-3 are satisfied. For purposes of section 199A only, deductions such as the deductible portion of the tax on self-employment income under section 164(f), the self-employed health insurance deduction under section 162(l), and the deduction for contributions to qualified retirement plans under section 404 are considered attributable to a trade or business to the extent that the individual’s gross income from the trade or business to the extent that the individual’s gross income from the trade or business is taken into account in calculating the allowable deduction, on a proportionate basis to the gross income received from the trade or business.
The above the line adjustments for self-employment tax, self-employed health insurance deduction, and the self-employed retirement deduction are examples of deductions attributable to a trade or business for purposes of section 199A. There is no inconsistency between the proposed and final regulations on this issue. QBI must be adjusted for these items in 2018.
<a rel="nofollow" target="_blank" href="
https://www.irs.gov/newsroom/tax-cuts-and-jobs-act-provision-11011-section-199a-qualified-business-i...>
