Exit Tax vs. Capital Gains Tax: What's the Difference for Expats?

Most US expats are familiar with capital gains tax, the tax you pay when you sell an investment for more than you paid for it. Exit tax is something far less understood, far less intuitive, and far more consequential. The critical distinction comes down to one word: unrealized. Capital gains tax applies when you actually sell an asset. Exit tax applies when you leave the US, whether or not you sold anything at all. For a covered expatriate with a large investment portfolio, the IRS can generate a six-figure tax bill on assets that have never changed hands, simply because a green card was surrendered or citizenship was renounced. 

Key Takeaways

• What triggers regular capital gains tax? An actual sale or disposition of an appreciated asset
• What triggers exit tax? Renouncing US citizenship or giving up a green card (for long-term residents), regardless of whether any asset is sold
• What is the core difference? Capital gains tax applies to realized gains; exit tax applies to unrealized gains via a deemed sale
• Who owes exit tax? Only covered expatriates, those meeting the $2M net worth, $211,000 average tax liability, or five-year compliance certification tests
• What is the 2026 exit tax exclusion? The first $910,000 of deemed gain is excluded
• Do regular capital gains rates apply to exit tax? Yes, long-term capital gains rates (up to 23.8%) apply to the deemed gain above the exclusion

For the majority of their lives, US taxpayers operate under a simple principle: you pay tax on investment gains when you realize them, meaning when you actually sell the asset and receive the proceeds. An investor who holds Apple stock for 20 years and watches it appreciate from $10,000 to $500,000 owes no tax until the day they sell. This is the realization principle, and it is the foundation of ordinary capital gains taxation in the US.

The exit tax breaks this principle entirely. Under IRC Section 877A, when a covered expatriate gives up their US status, the IRS does not wait for assets to be sold. It deems every worldwide asset to have been sold at fair market value on the day before departure, and taxes the resulting gains as if the sale actually occurred. The investor with $490,000 of unrealized gain in that stock owes exit tax on that gain the year they expatriate, even if the shares remain in their brokerage account, untouched, for another decade.

This is one of the most significant structural differences between exit tax and regular capital gains tax, and it is the reason why exit tax planning deserves a fundamentally different analytical framework than ordinary investment tax planning.

How Regular Capital Gains Tax Works

Capital gains tax is imposed when a capital asset is sold or disposed of at a gain. The gain is the difference between the sale price and the adjusted cost basis, the original purchase price, adjusted for improvements, depreciation, and other adjustments.

Short-Term vs. Long-Term Rates

The rate at which capital gains are taxed depends on how long the asset was held before sale:

Holding Period	Tax Treatment	2026 Rate
12 months or less	Short-term capital gain	Ordinary income rates, up to 37%
More than 12 months	Long-term capital gain	Preferential rates, 0%, 15%, or 20%
High-income earners (NIIT)	Net Investment Income Tax surcharge	Additional 3.8% on investment income
Maximum combined rate	Long-term gain + NIIT	23.8%

The Realization Requirement

The defining feature of regular capital gains tax is that no tax is owed until an asset is sold. This is not a planning strategy; it is the law. An asset can appreciate by millions of dollars over decades and trigger zero tax liability until a sale, exchange, or other taxable disposition occurs. This is why the exit tax feels so jarring to most expats: it removes the realization requirement entirely for the moment of expatriation.

What Triggers Capital Gains Tax for Expats

For US persons living abroad, ordinary capital gains tax applies to:

• Sales of US and foreign stocks, bonds, and securities
• Sales of US and foreign real estate
• Sales of business interests
• Dispositions of cryptocurrency
• Sales of personal property at gain

The FEIE does not apply to capital gains, only to earned income. Foreign tax credits may reduce double taxation on gains taxed in both the US and the country of residence, depending on the applicable tax treaty.

How Exit Tax Works: The Deemed Sale

The exit tax is formally called the mark-to-market tax under IRC Section 877A. It does not require any asset to actually be sold. Instead, on the day before your expatriation date, every worldwide asset you own is treated as if it were sold at fair market value. The resulting gain, real or entirely on paper, is calculated, the 2026 exclusion of $910,000 is applied, and the remaining gain is taxed.

Who Exit Tax Applies To

Exit tax only applies to covered expatriates, a specific legal classification that requires both:

1. Being either a US citizen renouncing citizenship OR a long-term resident (green card held in at least 8 of the last 15 tax years) terminating US tax residency
2. Meeting at least one of three tests:
• Net worth of $2 million or more on the date of expatriation
• Average annual US net income tax liability exceeding $211,000 for the five prior years
• Failure to certify five years of full US tax compliance on Form 8854

If you give up your green card after only 5 years of holding it, exit tax rules do not apply regardless of your net worth.

The Deemed Sale Calculation

The exit tax calculation follows these steps:

1. Determine the fair market value of every worldwide asset on the day before expatriation
2. Subtract the adjusted cost basis of each asset
3. Calculate gain or loss per asset
4. Total all gains and losses to arrive at net unrealized gain
5. Subtract the 2026 exclusion of $910,000
6. Tax the remaining gain at applicable capital gains rates (up to 23.8%)

Example:

Asset	Fair Market Value	Cost Basis	Gain
US brokerage portfolio	$1,500,000	$600,000	$900,000
Foreign property	$800,000	$600,000	$200,000
Foreign investment fund	$400,000	$350,000	$50,000
Business interest (loss)	$100,000	$150,000	($50,000)
Net gain			$1,100,000
Less 2026 exclusion			($910,000)
Taxable exit gain			$190,000

At 23.8% (20% long-term rate + 3.8% NIIT), the exit tax on $190,000 is $45,220, owed on assets that were never sold.

Side-by-Side: Exit Tax vs. Capital Gains Tax

Factor	Regular Capital Gains Tax	Exit Tax (Deemed Sale)
What triggers it?	Actual sale or disposition of an asset	Expatriation, no sale required
Who does it apply to?	All US persons with appreciated assets	Only covered expatriates
When is gain recognized?	At the time of actual sale	Deemed recognized the day before expatriation
Are unrealized gains taxed?	No, only realized gains	Yes, that is the entire mechanism
What rate applies?	0% / 15% / 20% long-term; up to 37% short-term	Long-term capital gains rates, up to 23.8%
Is there an exclusion?	$250,000 / $500,000 on primary home sale	$910,000 on all assets combined (2026)
Does it apply to foreign assets?	Yes, for US persons worldwide	Yes, worldwide assets included
Can the tax be deferred?	Yes, by not selling	No, deemed sale occurs at expatriation
What form is used?	Schedule D and Form 8949	Form 8854
Does it interact with FEIE?	No, FEIE only covers earned income	No, exit tax is separate from FEIE

The Key Conceptual Difference: Realized vs. Unrealized Gains

The most fundamental distinction between the two taxes is the treatment of unrealized gains, appreciation that exists on paper but has not been converted into cash through a sale.

Under ordinary capital gains tax, the IRS respects the realization principle. You own an asset, it goes up in value, you pay nothing until you sell. The gain exists, but it is not taxable yet. You control the timing.

Under the exit tax, the realization principle is overridden. The deemed sale rule creates a fictional sale on the day before you leave, making unrealized gains immediately taxable whether you wanted to sell or not, whether you have the cash to pay the bill or not, and whether you ever plan to sell in your lifetime or not.

This creates a particular hardship for expatriates whose wealth is concentrated in illiquid assets, a privately held business, a family property, or a minority stake in a partnership. The exit tax is calculated on fair market value, which may require a formal appraisal. The tax bill is real and immediately due, even if the asset cannot be sold quickly to generate the cash to pay it.

Where Exit Tax and Capital Gains Tax Overlap

Despite their fundamental differences, the two taxes connect in important ways:

The Same Rates Apply

The exit tax does not create a new, higher rate. Gains from the deemed sale are taxed at the same long-term capital gains rates that apply to actual sales, 0%, 15%, or 20% depending on taxable income, plus the 3.8% NIIT where applicable. Short-term gains on assets held less than 12 months are taxed at ordinary income rates, also the same as a regular sale. The exit tax is punitive not because of its rate, but because it taxes gains that would otherwise never have been recognized.

The $910,000 Exclusion Acts Like a Capital Gains Exemption

The 2026 exclusion of $910,000 functions similarly to the primary home sale exclusion under regular capital gains rules, a threshold below which gain is not subject to tax. An expatriate with less than $910,000 in total net unrealized gains pays no exit tax on the deemed sale even if they are a covered expatriate. The exclusion makes exit tax irrelevant for many covered expatriates with modest investment portfolios.

Both Taxes Apply After Expatriation on US-Source Income

Exit tax resolves the US tax obligation on unrealized gains at the moment of departure. But it does not end all US tax obligations. After expatriation, a former US person who remains a covered expatriate continues to face 30% withholding on certain US-source income, including dividends, interest, and distributions from US retirement accounts and trusts. Regular capital gains tax also continues to apply to gains from US real property regardless of residency status under FIRPTA rules.

Special Asset Categories: Where Exit Tax Differs Further from Capital Gains

The deemed sale mechanism does not apply uniformly to every asset. Several categories depart significantly from ordinary capital gains treatment:

Retirement Accounts (401(k) and IRAs)

Under regular capital gains rules, you pay no tax on a 401(k) or IRA until you take distributions, and even then it is ordinary income, not capital gains. Under the exit tax, the entire balance of a 401(k) or traditional IRA is treated as immediately distributed at the time of expatriation, taxed at ordinary income rates with 30% withholding applied by the custodian. The entire tax deferral benefit built over decades is eliminated in a single event.

Deferred Compensation

Stock options, nonqualified deferred compensation plans, and similar arrangements that would ordinarily be taxed when received are accelerated to the date of expatriation under the exit tax rules, regardless of when the underlying compensation is eventually paid out.

Non-Grantor Trusts

Future distributions from a non-grantor trust to a covered expatriate are subject to a 30% withholding tax on the taxable portion. This is not a capital gains tax; it is a separate withholding regime that applies to each future distribution, regardless of when the trust assets were acquired or what type of income they represent.

Practical Implications for Expats Planning to Leave

Understanding the difference between exit tax and capital gains tax has direct planning implications:

Harvest losses before expatriating. Realized losses in the years before expatriation reduce both the cost basis adjustment and the net unrealized gain subject to exit tax. Selling depreciated assets before the expatriation date converts paper losses into realized losses that offset gains in the exit tax calculation.

Manage the timing of asset dispositions. Assets actually sold before the expatriation date are subject to regular capital gains tax, not exit tax. In some cases, selling assets before expatriation at regular rates, particularly in a year with significant offsetting losses, produces a better outcome than leaving them for the deemed sale calculation.

The $910,000 exclusion resets on actual sale. After expatriation, if you sell an asset that was subject to the exit tax deemed sale, your new cost basis is the fair market value used in the exit tax calculation. You are not double-taxed on the same gain. But if you paid exit tax on unrealized gain that later disappears due to a market decline, there is generally no refund mechanism.

Cure compliance gaps before certifying. Failing the five-year compliance certification on Form 8854 triggers covered expatriate status automatically, meaning exit tax applies to unrealized gains even for expatriates with modest net worth. Addressing prior FBAR, PFIC, and information return gaps before expatriation avoids this outcome entirely.

How NSKT Global Can Help

The interaction between exit tax and regular capital gains tax is not theoretical; it determines the total US tax cost of permanently leaving the US system, and it can be optimized significantly with advance planning. NSKT Global helps expats model the exit tax liability on their specific asset portfolio, compare it against a regular capital gains disposal strategy, identify pre-expatriation loss harvesting and basis optimization opportunities, and determine whether the timing of expatriation itself, across tax years or relative to specific asset dispositions, meaningfully changes the total tax outcome. For expats whose primary concern is the interaction between exit tax and retirement accounts, NSKT Global also structures the Form W-8CE strategy to manage the deferred compensation withholding obligation.

People Also Ask

Q: What is the main difference between exit tax and capital gains tax?

Capital gains tax applies when you actually sell an appreciated asset. Exit tax applies when you renounce US citizenship or give up a long-term green card, treating all worldwide assets as sold at fair market value the day before departure, whether or not any sale occurred.

Q: Does exit tax apply at the same rate as capital gains tax?

Yes. Gains from the exit tax deemed sale are taxed at the same rates as actual capital gains, up to 20% for long-term gains plus 3.8% NIIT, for a maximum rate of 23.8%. Short-term gains are taxed at ordinary income rates.

Q: Can you owe exit tax even if you have not sold anything?

Yes. That is the core mechanism of exit tax. The deemed sale rule creates a fictional sale on the day before expatriation. You owe tax on unrealized gains even if every asset remains in your portfolio, untouched, after you leave.

Q: Does the $910,000 exclusion work the same as a capital gains exemption?

It functions similarly; gains below $910,000 in aggregate are not subject to exit tax. However, unlike the primary home sale exclusion, which applies per transaction, the $910,000 is a single lifetime exclusion applied once to the total net unrealized gain across all assets in the year of expatriation.