Federal income taxes are not deductible on your federal return, and neither is the Social Security and Medicare tax withheld from your paycheck. So when people ask whether federal taxes are deductible, the honest answer is: the big one you’re probably thinking of is not, but several other federal tax payments are, and a few of them can shave a meaningful amount off what you owe. Self-employment tax, foreign income tax, business excise tax, and estate tax tied to inherited income each have their own rules.
The Federal Income Tax Itself Is Off Limits
Section 275 of the Internal Revenue Code flatly prohibits deducting federal income tax from your federal taxable income. The reason is circular math: if the tax reduced the income it’s calculated on, the tax would drop, which would change the deduction, which would change the tax. Congress closed that loop by making the ban absolute. It applies whether you itemize on Schedule A or take the standard deduction.1Office of the Law Revision Counsel. 26 USC 275 – Certain Taxes
The same statute blocks the employee share of FICA. If you’re a W-2 employee, the 6.2% Social Security and 1.45% Medicare withholdings on your check do not reduce your taxable income.1Office of the Law Revision Counsel. 26 USC 275 – Certain Taxes
Half of Self-Employment Tax Is Deductible
Self-employed workers pay both sides of Social Security and Medicare: a combined 15.3%, made up of 12.4% Social Security on earnings up to $184,500 in 2026 and 2.9% Medicare on all earnings.2Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes)3Social Security Administration. Contribution and Benefit Base A W-2 employee only sees half that come out of their check; the employer covers the rest and deducts it as a business expense.
Section 164(f) evens things out by letting you deduct one-half of the self-employment tax you owe. That half stands in for the employer share.4Office of the Law Revision Counsel. 26 USC 164 – Taxes
Two features make this worth paying attention to. It’s an above-the-line adjustment, so you don’t need to itemize. And because it lowers adjusted gross income, it can help you qualify for other benefits that phase out as AGI climbs. You claim it on Schedule 1 (Form 1040), Line 15, with Schedule SE attached to show the calculation.5Internal Revenue Service. Schedule 1 (Form 1040) – Additional Income and Adjustments to Income
Two limits trip people up. The deduction reduces income tax only; it does not reduce the self-employment tax itself. And the additional 0.9% Medicare surtax that kicks in above $200,000 (or $250,000 for joint filers) is not part of the deductible half.4Office of the Law Revision Counsel. 26 USC 164 – Taxes
Foreign Income Tax: Deduction or Credit
If you paid income tax to another country’s government, Section 164(a) lets you claim those payments as an itemized deduction. Or you can take the foreign tax credit on Form 1116.4Office of the Law Revision Counsel. 26 USC 164 – Taxes
The credit almost always wins. A credit cuts your tax bill dollar for dollar; a deduction only cuts the income the tax is calculated on. Pay $3,000 in foreign tax at a 22% marginal rate and the deduction saves you around $660, while the credit saves the full $3,000. The credit also does not require itemizing, and unused amounts can be carried back or forward to other years.6Internal Revenue Service. Foreign Tax Credit – Choosing to Take Credit or Deduction
The IRS suggests running your return both ways. The deduction occasionally comes out ahead when your foreign income is small relative to your total income and credit limitation rules eat into the credit’s value.
Federal Excise Tax Paid by a Business
Federal excise taxes on fuel, heavy vehicles, airline tickets, and similar goods are not deductible when you pay them as personal expenses. Pay them in the course of running a business and Section 162 treats them as ordinary and necessary business expenses.7Office of the Law Revision Counsel. 26 USC 162 – Trade or Business Expenses
A trucking company deducts the federal heavy vehicle use tax as a cost of operations. A business that fuels its fleet deducts the embedded federal fuel excise tax as part of the fuel cost. The test is whether the expense ties to a trade or business rather than personal use, and the deduction goes on the business return, not on a personal Schedule A.
Estate Tax Attributable to Inherited Income
If you inherit income that the decedent never got to receive, like unpaid salary, a traditional IRA balance, or deferred compensation, the tax code calls that income in respect of a decedent (IRD). IRD can be taxed twice: once through federal estate tax on the estate, and again through income tax when you actually receive the money.8Office of the Law Revision Counsel. 26 USC 691 – Recipients of Income in Respect of Decedents
Section 691(c) softens that with a deduction for the portion of estate tax attributable to the IRD you received. The calculation compares the estate tax that was actually paid against what it would have been without the IRD items, then allocates a proportional share to each beneficiary.9eCFR. 26 CFR 1.691(c)-1 – Deduction for Estate Tax Attributable to Income in Respect of a Decedent
Most people need professional help here because the math depends on the estate’s full return. The payoff can be large. On a sizable inherited IRA from an estate taxed at 40%, the 691(c) deduction can offset a meaningful share of the income tax you would otherwise owe on the distributions.
States That Let You Deduct Federal Tax
The federal rule is one thing; your state return is another. A small group of states, historically Alabama, Iowa, Louisiana, Missouri, and Oregon, have let residents deduct some or all of their federal income tax when calculating state taxable income. Alabama and Louisiana have allowed a full deduction, with Louisiana specifically including the 3.8% net investment income tax. Missouri caps a partial deduction at $5,000 for individuals and $10,000 for combined returns. Oregon caps the deduction at $8,750 for 2026 and phases it out above $145,000 for single filers and $290,000 for joint filers. Iowa has passed significant tax reform in recent years.
These rules move around. Confirm the current treatment with your state revenue department before you rely on it.
Penalties for Deducting What You Cannot Deduct
Claiming federal income tax as a deduction on your federal return is not just wasted ink. The IRS treats certain positions, including that one, as frivolous, and a return based on a frivolous position carries a flat $5,000 penalty under Section 6702. You can withdraw the submission within 30 days of IRS notice to avoid the penalty, but few people know that window exists until it has closed.10Office of the Law Revision Counsel. 26 USC 6702 – Frivolous Tax Submissions
A deduction that isn’t frivolous but still isn’t allowed can still cost you. Section 6662 imposes a 20% accuracy-related penalty on the resulting underpayment, and 40% if the IRS finds a gross valuation error.11Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments The frivolous penalty is the more dangerous of the two because it applies per submission, whether or not any tax was underpaid.