Nothing. There will be a calculation on your 2018 tax return to take the 20reduction if you qualify for it. Note that this will be the return you file inspring of 2019 for tax year 2018. It does not affect your 2017 return that youwill file in the next few months.To qualify you have to have business income from a business that is not apersonal service business and your taxable income has to be less than 157500for a single taxpayer or 315000 for a joint filer.Income from a sole proprietorship partnership or S Corp qualifies. Note thatW2 wages from an S Corp and guaranteed payments from a partnership do NOTqualify.