A deemed disposition is a tax rule that treats you as if you sold property at its fair market value on a specific date, triggering a taxable capital gain or loss on your return for that year even though no actual sale took place and no cash changed hands. The rule shows up most often when someone gives up US citizenship, when a corporate stock purchase is elected to be treated as an asset purchase, and in certain foreign investment situations where the IRS wants to lock in gains that might otherwise escape US tax.
How the Rule Works
A normal sale has three parts: you transfer property, you receive money, and you report the result. A deemed disposition keeps only the third part. The tax code declares a sale at fair market value on a set date, computes the gain against your adjusted basis, and expects the tax with your next return.
The math is standard. Fair market value on the trigger date, minus your adjusted basis (original cost, plus improvements, minus depreciation), equals your gain or loss. If the calculation produces a gain, it is capital in character and taxed at whatever rate your holding period and income put you in. The asset’s basis then resets to the fair market value used in the calculation, so when you eventually sell for real, you are not taxed again on the same appreciation.
The catch is cash. A real sale funds its own tax bill. A deemed disposition does not. You can owe tax on a large paper gain with nothing liquid to pay it, and that liquidity gap is the hardest part of the rule for most people who run into it.
Expatriation: The Exit Tax
The biggest deemed disposition individuals face is the expatriation tax under IRC Section 877A. If you give up US citizenship or end long-term permanent residency and you 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.1Office of the Law Revision Counsel. 26 USC 877A – Tax Responsibilities of Expatriation The net gain from that hypothetical sale is taxed in the year you leave.
You are 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 prior five years above an inflation-adjusted threshold, or failure to certify five years of federal tax compliance.2Internal Revenue Service. Expatriation Tax
The statute excludes a base amount of net gain, adjusted annually for inflation. For 2025, the exclusion was $3,054,000. Gain above the exclusion is taxed at the capital gains rate that applies to your income and holding period.1Office of the Law Revision Counsel. 26 USC 877A – Tax Responsibilities of Expatriation
You report the deemed sale on Form 8854, the Initial and Annual Expatriation Information Statement.3Internal Revenue Service. Instructions for Form 8854 – Initial and Annual Expatriation Statement If paying the bill in full is not possible, the IRS allows an election to defer the tax attributable to specific property deemed sold, with interest accruing on the deferred balance.2Internal Revenue Service. Expatriation Tax
Corporate Stock Purchases Treated as Asset Sales
In acquisitions, buyers usually want an asset purchase for the stepped-up basis, and sellers usually want a stock sale for simplicity. Two Code provisions bridge the gap by treating a stock transaction as a deemed asset sale.
Section 338 Elections
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.4Office of the Law Revision Counsel. 26 USC 338 – Certain Stock Purchases Treated as Asset Acquisitions The buyer picks up a stepped-up basis and higher future depreciation and amortization. The cost is immediate gain at the target level. A Section 338(h)(10) variation requires both buyer and seller to consent and produces only one level of tax.
Section 336(e) Elections
Section 336(e) covers a broader set of transactions. When a parent corporation sells, exchanges, or distributes 80% or more of a subsidiary’s stock, the parent can elect to treat the transaction as a disposition of the subsidiary’s assets rather than its stock.5Office of the Law Revision Counsel. 26 US Code 336 – Gain or Loss Recognized on Property Distributed in Complete Liquidation Unlike Section 338, it does not require a corporate buyer or mutual consent, so it fits deal structures that Section 338 cannot reach.
Two Other Situations That Trigger a Deemed Sale
PFIC Mark-to-Market Election
US taxpayers holding shares in a passive foreign investment company can elect mark-to-market treatment under IRC Section 1296. The election creates a deemed disposition at the end of each tax year: if year-end fair market value exceeds your adjusted basis, you include the excess in ordinary income; if basis exceeds value, you deduct the difference, limited to prior mark-to-market gains you have already reported.6Office of the Law Revision Counsel. 26 US Code 1296 – Election of Mark to Market for Marketable Stock The annual sale fiction is the price of avoiding the punitive interest charges the default PFIC regime imposes.
Qualified Opportunity Fund Deferral End
If you deferred capital gain by investing in a Qualified Opportunity Fund, the deferral ends on the earlier of the date you sell the investment or December 31, 2026.7Internal Revenue Service. Opportunity Zones Frequently Asked Questions On that date the deferred gain becomes taxable whether or not you have sold the fund interest. The recognized amount is the lesser of the original deferred gain (reduced by any permanent basis increases earned through the holding period) or the fund investment’s fair market value on December 31, 2026. The gain keeps its original character.
What Is Not a Deemed Disposition
Several events change an asset’s basis but do not trigger current gain, and it is worth naming them because they get confused with deemed dispositions.
Inheritance. When you inherit property, its basis resets to fair market value on the date of death.8Office of the Law Revision Counsel. 26 USC 1014 – Basis of Property Acquired From a Decedent Appreciation during the decedent’s life is erased for income tax purposes, not recognized. Inherited property also gets automatic long-term holding period treatment.9Office of the Law Revision Counsel. 26 US Code 1223 – Holding Period of Property Retirement accounts are the main exception: withdrawals stay taxable as ordinary income to the beneficiary.10Internal Revenue Service. Gifts and Inheritances
Lifetime gifts. A gift of appreciated property is not a taxable event to the recipient. You take the donor’s basis (carryover basis) and recognize the built-in gain only when you eventually sell.11Office of the Law Revision Counsel. 26 US Code 1015 – Basis of Property Acquired by Gifts and Transfers in Trust
Converting a home to a rental. No gain is recognized when you begin renting out a former residence. You establish a depreciable basis equal to the lesser of fair market value on the conversion date or your adjusted basis at that time.12Internal Revenue Service. Publication 551 (12/2025), Basis of Assets13Internal Revenue Service. Publication 523 (2025), Selling Your Home14Office of the Law Revision Counsel. 26 USC 121 – Exclusion of Gain From Sale of Principal Residence
Figuring the Tax
Every deemed disposition uses the same formula: fair market value on the trigger date, minus adjusted basis, equals the gain or loss. Adjusted basis starts with original cost, rises for capital improvements, and falls for depreciation and other basis-reducing deductions.
Rate depends on holding period. Property held more than a year qualifies for long-term capital gains rates of 0%, 15%, or 20%, with the brackets set by taxable income and filing status. Property held a year or less produces short-term gain taxed at ordinary income rates. High-income taxpayers also owe the 3.8% net investment income tax, which can push the top effective rate on long-term gain to 23.8%.
A deemed disposition that produces a capital loss follows the ordinary loss rules. Losses offset capital gains from other transactions, and any remaining net loss offsets up to $3,000 of ordinary income per year ($1,500 if married filing separately), with unused amounts carried forward indefinitely.15Internal Revenue Service. Topic No. 409, Capital Gains and Losses
Reporting and Paying
The gain or loss goes on Form 8949, Sales and Other Dispositions of Capital Assets, using the deemed disposition date, fair market value as the sale price, and your adjusted basis.16Internal Revenue Service. About Form 8949, Sales and Other Dispositions of Capital Assets Totals move to Schedule D of Form 1040 and combine with your other capital transactions for the year.17Internal Revenue Service. About Schedule D (Form 1040), Capital Gains and Losses Covered expatriates file Form 8854 in addition, which details the mark-to-market calculation and certifies five years of tax compliance.3Internal Revenue Service. Instructions for Form 8854 – Initial and Annual Expatriation Statement
Documentation is where filings often fall apart. Publicly traded securities are easy since closing prices are on record. Real estate, private business interests, and collectibles need a professional appraisal dated as close as possible to the trigger event. Without solid support for both fair market value and adjusted basis, the IRS can adjust your gain upward.
Cash is the last problem to solve. Because a deemed disposition can generate a large tax liability with no matching proceeds, estimated tax underpayment penalties are a live risk. The penalty depends on the amount owed, how long it goes unpaid, and the quarterly underpayment rate.18Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty If the triggering event happened later in the year, Form 2210 Schedule AI lets you annualize income to reduce the penalty. Setting aside cash before the trigger date is almost always cheaper than paying penalties and interest afterward.