A deemed disposition is a US tax rule that treats you as having sold property at fair market value on a specific date, even though no actual sale took place, and the hypothetical sale triggers a capital gain or loss on that year’s return. The rule exists so the IRS can tax appreciation that would otherwise escape the system, and it shows up most often in four situations: giving up US citizenship or long-term residency, certain corporate stock acquisitions elected to be treated as asset sales, mark-to-market elections for passive foreign investment companies, and the scheduled end of Qualified Opportunity Fund gain deferral.
How the Rule Works and Why It Stings
In a real sale, you transfer property, receive cash, and report the gain. A deemed disposition skips the first two steps. The tax code declares that you sold at fair market value on the trigger date, calculates gain or loss against your adjusted basis, and sends you a bill. The asset’s basis then resets to the fair market value used in the calculation, so you aren’t taxed twice when you eventually sell for real.
The gain equals fair market value on the trigger date minus adjusted basis (generally original cost, plus improvements, minus depreciation claimed). Long-term rates apply if the holding period exceeded one year; short-term gains are taxed as ordinary income. The 3.8% net investment income tax can push the top effective rate on long-term gains to 23.8%. Losses from a deemed disposition offset other capital gains, and up to $3,000 of net capital loss ($1,500 for married filing separately) can offset ordinary income each year, with the rest carried forward.1Internal Revenue Service. Topic No. 409, Capital Gains and Losses
The practical problem is liquidity. A real sale generates proceeds that cover the tax. A deemed disposition produces phantom income with no cash in hand. That mismatch is what catches people off guard when the deemed gain is large.
Expatriation: The Exit Tax
The biggest deemed disposition for individuals is the expatriation tax under IRC Section 877A. If you renounce US citizenship or end long-term permanent residency and qualify as a “covered expatriate,” the IRS treats every asset you own worldwide as sold at fair market value on the day before your expatriation date.2Office of the Law Revision Counsel. 26 USC 877A – Tax Responsibilities of Expatriation Any net gain is taxable that year whether or not you sell anything.
You’re a covered expatriate if you meet any one of three tests: net worth of $2 million or more, average annual net income tax liability over the five prior years above an inflation-adjusted threshold, or failure to certify five years of federal tax compliance.3Internal Revenue Service. Expatriation Tax
A sizable chunk of gain escapes the tax. The first $600,000 of net gain is excluded, with the base amount adjusted annually for inflation. For 2025 the exclusion stood at $3,054,000. Gain above the exclusion is taxed at the capital gains rate applicable to your income and holding period.2Office of the Law Revision Counsel. 26 USC 877A – Tax Responsibilities of Expatriation
Covered expatriates report the deemed sale on Form 8854, the Initial and Annual Expatriation Information Statement, which also carries the five-year tax-compliance certification.4Internal Revenue Service. Instructions for Form 8854 – Initial and Annual Expatriation Statement If you can’t pay immediately, you can elect to defer the tax attributable to deemed-sold property, but interest accrues on the deferred balance.3Internal Revenue Service. Expatriation Tax
Corporate Stock Deals Treated as Asset Sales
In acquisitions, buyers often want asset treatment (for the stepped-up basis and future depreciation) while sellers want stock treatment. Two elections bridge the gap by making a stock purchase look like an asset sale for tax purposes.
When a corporation makes a “qualified stock purchase” of at least 80% of a target’s stock, it can elect under IRC Section 338 to treat the target as having sold all its assets at fair market value on the acquisition date and repurchased them the next day as a new corporation.5Office of the Law Revision Counsel. 26 USC 338 – Certain Stock Purchases Treated as Asset Acquisitions The deemed sale triggers gain at the target level in exchange for the buyer’s stepped-up basis. The Section 338(h)(10) variation requires both sides to agree and is structured so only one level of tax applies.
Section 336(e) works similarly when a parent corporation sells, exchanges, or distributes all of its stock in a subsidiary meeting the 80% threshold. The parent elects to treat the transaction as a disposition of the subsidiary’s assets rather than its stock.6Office of the Law Revision Counsel. 26 US Code 336 – Gain or Loss Recognized on Property Distributed in Complete Liquidation A 336(e) election doesn’t require a corporate buyer or mutual agreement, which makes it more flexible in deal structuring.
PFIC Mark-to-Market Election
US taxpayers holding shares in a passive foreign investment company face harsh default tax rules. Electing mark-to-market treatment under IRC Section 1296 creates a deemed disposition at the end of every tax year. If year-end fair market value exceeds adjusted basis, the excess is ordinary income. If basis exceeds fair market value, you can deduct the difference, but only up to the net mark-to-market gains you’ve previously included.7Office of the Law Revision Counsel. 26 US Code 1296 – Election of Mark to Market for Marketable Stock The annual deemed sale avoids the punitive interest charges that would otherwise apply.
Qualified Opportunity Fund: The 2026 Recognition Date
Taxpayers who deferred capital gains by investing in a Qualified Opportunity Fund face a mandatory recognition event. The deferral ends on the earlier of the date you sell the investment or December 31, 2026.8Internal Revenue Service. Opportunity Zones Frequently Asked Questions At that point the deferred gain becomes taxable whether or not you’ve sold the QOF interest. The amount recognized is the lesser of the original deferred gain (reduced by any permanent basis increases earned for holding the investment) or the investment’s fair market value on December 31, 2026. The character of the gain is preserved, so a long-term gain stays long-term.
What Looks Like a Deemed Disposition But Isn’t
Several events reset or shift an asset’s basis without triggering current gain. Confusing them with a deemed disposition leads to the wrong answer about what you owe and when.
Inherited property. When you inherit property, its basis resets to fair market value on the date of the decedent’s death.9Office of the Law Revision Counsel. 26 USC 1014 – Basis of Property Acquired From a Decedent If a parent bought stock for $20,000 and it was worth $200,000 at death, your basis is $200,000. Selling the next day for $200,000 produces no taxable gain. That appreciation is erased, not taxed, which is the opposite of what a deemed disposition does. Inherited assets are also automatically treated as long-term regardless of how briefly you hold them.10Office of the Law Revision Counsel. 26 US Code 1223 – Holding Period of Property Retirement accounts are the exception: inherited IRA and 401(k) withdrawals remain taxable as ordinary income.11Internal Revenue Service. Gifts and Inheritances
Lifetime gifts. No tax is due when you receive appreciated property as a gift. You take the donor’s basis (carryover basis), so the built-in gain travels with the asset and is recognized only when you eventually sell.12Office of the Law Revision Counsel. 26 US Code 1015 – Basis of Property Acquired by Gifts and Transfers in Trust A special dual-basis rule applies if fair market value at the time of the gift is lower than the donor’s basis, which prevents a built-in loss from being transferred.13Internal Revenue Service. Property (Basis, Sale of Home, etc.)
Converting a home to a rental. Changing a personal residence into a rental does not trigger gain recognition. You establish a depreciable basis equal to the lesser of fair market value on the conversion date or your adjusted basis at that time.14Internal Revenue Service. Publication 551 (12/2025), Basis of Assets15Internal Revenue Service. Publication 523 (2025), Selling Your Home16Office of the Law Revision Counsel. 26 USC 121 – Exclusion of Gain From Sale of Principal Residence
Reporting a Deemed Disposition
Any deemed disposition that produces a recognized gain or loss is reported on Form 8949, Sales and Other Dispositions of Capital Assets, with the trigger date as the sale date and fair market value as the sale price.17Internal Revenue Service. About Form 8949, Sales and Other Dispositions of Capital Assets Totals flow to Schedule D of Form 1040, where they combine with other capital gains and losses for the year.18Internal Revenue Service. About Schedule D (Form 1040), Capital Gains and Losses Covered expatriates also file Form 8854.4Internal Revenue Service. Instructions for Form 8854 – Initial and Annual Expatriation Statement
Documentation is where filings tend to fall apart. For publicly traded securities, the closing price on the trigger date settles fair market value. For real estate, private business interests, or collectibles, you need a professional appraisal dated as close as possible to the event. Without solid support for both fair market value and basis, the IRS can challenge the numbers and adjust the gain upward.
Because deemed dispositions can produce large gains without matching cash, estimated tax penalties are a live risk. The underpayment penalty depends on how much you owed, how long it went unpaid, and the quarterly interest rate.19Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty If the trigger happened late in the year, Form 2210 Schedule AI lets you annualize income and reduce the penalty. Lining up the cash before the event is almost always cheaper than paying penalties and interest after it.