If you run a small partnership or S corporation, and you plan to use Section 199A deduction in 2019 or your enjoyed in 2018 a nice Section 199A deduction, you probably want to review the new instructions:
https://www.irs.gov/pub/irs-dft/i8995--dft.pdfIRS has
really shrunk the deduction for some folks.
The main culprit is they make you, if you're partnership or S corp, reduce your QBI for your self-employed health insurance twice...
E.g., a sole proprietor making (for easy calculation) $100,000 a year and paying say $10,000 a year for insurance, has $90,000 of income that plugs into the Section 199A formula.
A partnership partner or S corporation shareholder-employee making same $100,000 a year and paying
same $10,000 for insurance has $80,000 of income that plugs into the Section 199A formula.