I could add details, but it comes down to how you interpret some IRS docs.
This page says:
https://www.irs.gov/newsroom/qualified-business-income-deductionQBI is the net amount of qualified items of income, gain, deduction and loss from any qualified trade or business... Generally this includes, but is not limited to, the deductible part of self-employment tax. So I guess that means don't subtract it?
However, this intuit thread from 2018 has some rationale from section 199 (which I can't find online):
https://proconnect.intuit.com/community/individual/help/2018-qbi-reduced-by-self-employment-tax-heal...All deductions attributable to a trade or business should be taken into account for purposes of computing QBI except to the extent provided by section 199A and these regulations. Accordingly, §1.199A-3(b)(1)(vi) provides that, in general, 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 otherwise satisfied. Thus, for purposes of section 199A, deductions such as the deductible portion of the tax on self-employment income under section 164(f),
Thanks!
