What Is the US Exit Tax?
IRC §877A establishes the US expatriation tax for American citizens who relinquish citizenship and for permanent residents (green card holders) who definitively abandon that status. The current rule was introduced by the Heroes Earnings Assistance and Relief Tax Act of 2008 (HEART Act), replacing the prior regime under IRC §877.
The core mechanism is the mark-to-market deemed sale: the law treats the covered expatriate as having sold all worldwide assets at fair market value on the day before the expatriation date. Net gains exceeding the annual exclusion are taxed on that final US return.
Who Is a Covered Expatriate?
Covered expatriate status applies to anyone who meets any one of the following three tests in the year of expatriation:
Net worth test: worldwide net worth exceeds $2 million on the date of expatriation.
Average tax liability test: the average annual US federal tax liability for the five tax years immediately preceding the year of expatriation exceeds the inflation-indexed threshold. For tax year 2026 that threshold is approximately $201,000 (the exact figure is published in the IRS annual Revenue Procedure).
Certification test: the taxpayer cannot certify under penalty of perjury that they have complied with all US federal tax obligations for the five preceding years. This certification is made on Form 8854 (Initial and Annual Expatriation Statement).
How the Mark-to-Market Calculation Works
Once covered expatriate status is established, the following rules apply:
Inclusion base: the net gain from the deemed sale of all worldwide assets (stocks, partnership interests, real property, savings accounts, intellectual property rights, and other property). Unrealized losses are also counted, which can reduce the base.
Exclusion: the first approximately $890,000 of net gain (2026 figure, indexed annually) is excluded. Gains above that amount are taxed at ordinary income rates or at the preferential long-term capital gains rate depending on the asset’s character.
Assets outside the mark-to-market regime: qualified retirement plans (401(k), IRAs) and deferred compensation arrangements are governed by special rules. Rather than a deemed sale, a 30% withholding tax applies on the present value of the deferred amounts as of the expatriation date.
Compliance obligations: the covered expatriate must file Form 8854 in the year of expatriation and potentially in subsequent years if deferred assets remain. Failure to file can result in automatic covered expatriate treatment even if none of the three substantive tests are met.
What §877A Is Not
An important misconception worth clearing up: IRC §877A does not trigger upon a mere change of tax residence. A US citizen who moves to Spain remains a US citizen; their tax situation changes (they must now coordinate IRPF and US worldwide income obligations), but there is no expatriation event and no §877A exit tax for as long as they hold their citizenship. The exit tax also does not apply to non-US nationals who lived in the United States on a work or student visa and then returned home — the test is the ≥8-year green card, not tax residence.
Coordination with Spanish Tax
For a client weighing citizenship renunciation while residing in Spain, the combined effects are:
- US side (IRC §877A): unrealized worldwide gains above approximately $890,000 are taxed in the US in the year of expatriation.
- Spanish side (Art. 95 bis LIRPF): if the taxpayer also loses Spanish tax residence in the same period (for example, by relocating to a third country) and holds qualifying participations (>€1M or >25%/€4M), Spain’s AEAT may also tax unrealized gains on those same participations.
Double taxation on the same unrealized gains is theoretically possible, though the Spain-US Treaty and the bilateral Foreign Tax Credit must be analyzed to determine the available credit in each direction.
At BMC we plan the sequence of these events — change of Spanish tax residence, US citizenship renunciation, asset liquidation or reorganization — to minimize total tax cost. The optimization window is narrow and reversibility is extremely limited once citizenship is formally relinquished.
See also: Tax Residence in Spain · Tax Treaty · Modelo 720 · Double Taxation