The most beneficial deductions are business deductions that offset both income tax and, depending upon the circumstances, self-employment tax. For 2018, the self-employment tax rate is 12.4% of the first $128,400 of net self-employment income plus 2.9% for the Medicare tax, with no cap. Some high-income taxpayers may pay an additional 0.9% Medicare tax. For self-employed businesses with less than $128,400 of net income, the self-employment tax rate is 15.3%. Thus, for small businesses with profits of less than $128,400, the benefit derived from deductions generally will include the taxpayer’s tax bracket plus 15.3%. For example, for a taxpayer in the 24% tax bracket, the benefit could be as much as 39.3% (24% + 15.3%) of the deduction. If the deduction were $2,000, the tax savings could be as much as $806 or more, when the taxpayer’s state income tax bracket is included.