What Does a Tax Deduction Save You?

Taxpayers frequently ask what benefit is derived from a tax deduction.  Unfortunately, there is no straightforward answer.  The reason the benefit cannot be determined simply is because some deductions are above-the-line, others must be itemized, some must exceed a threshold amount before being deductible, and certain ones are not deductible for alternative minimum tax purposes, while business deductions can offset both income and self-employment tax.  In other words, there are many factors to consider, and the tax benefits differ for each individual, depending on his or her particular situation.

For most non-business deductions, the savings are based upon your tax bracket.  For example, if you are in the 24% tax bracket, a $1,000 deduction would save you $240 in taxes.  However, if taxable income is close to transitioning into the next-lower tax bracket, the benefit will be less.  You also need to consider whether the particular deduction is allowed on your state return and what your state tax bracket is to determine the total tax savings.

Some deductions, such as IRA and self-employed retirement plan contributions, alimony, student loan interest, etc., are adjustments to income or what we call above-the-line deductions.  These deductions, to the extent permitted by law, provide a dollar deduction for every dollar claimed.  Deductions that fall into the itemized category must exceed the standard deduction for your filing status before any benefit is derived.  In addition, the medical deductions are reduced by 10% of your AGI (income). Under the rules of the 2017 tax reform, the state and local taxes deduction is limited to $10,000, no deduction is allowed for home equity interest, and deductions such as employee business expenses and investment expenses aren’t deductible at all in years 2018 through 2025. Taxpayers subject to the alternative minimum tax are not able to deduct any taxes.

The most beneficial deductions, business deductions, fall into two categories: employee business expenses, which are treated as miscellaneous itemized deductions but aren’t deductible in years 2018-2025, and self-employed business expenses that offset both income tax and, depending upon the circumstances, self-employment tax.  For 2019, the self-employment tax rate is 12.4% of the first $132,900 of income subject to SE tax plus 2.9% for the Medicare tax with no cap.  In addition, for high-income taxpayers, an additional 0.9% Medicare tax may apply.  For self-employed businesses with less than $132,900 of net income, the SE tax rate is 15.3%.  Thus, for small businesses with profits of less than $132,900, 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 $786 and more when the taxpayer’s state income tax bracket is included.

If you are planning an expenditure and expect the tax deduction to help cover the cost, please give us a call in advance to ensure that the tax benefit is what you anticipate.


Isler Northwest LLC is a firm of certified public accountants and business advisors based in Portland, Oregon. Our local, regional, and global resources, our expertise, and our emphasis on innovative solutions and continuity create value for our clients. Our service goals at Isler Northwest is to earn our clients trust as their primary business and financial advisors.

Isler Northwest

(503) 224-5321

1300 SW 5th Avenue
Suite 2900
Portland, Oregon 97201