When You Become a US Taxpayer, and Why the Date Is a Hard Deadline
There is a single day that separates two very different tax lives. Before it, you are a nonresident: the US taxes only your US-source income and stays outside your estate and gifts for most of what you own. On and after it, you are a worldwide US taxpayer, reporting income from everywhere and filing a stack of foreign-account and foreign-asset forms. That day is your residency starting date, and everything valuable in a pre-immigration plan has to be finished, and for any transfer made final, before it.
You can reach that date two ways. The first is the green-card test: you become a US tax resident the first day you are physically present in the US as a lawful permanent resident. A green-card client who "isn't really moving yet" can start worldwide taxation with one airport landing. The second is the substantial-presence test (a day-counting formula that can make you a US taxpayer with no green card at all): 31 days in the US this year, plus a weighted total of 183 days across three years, counting this year in full, one-third of last year, and one-sixth of the year before. Because prior years feed the count, a marginal snowbird can trip it without meaning to.
The first year is usually a split, or dual-status, year: a nonresident before the date and a resident after. So the first thing we do is run the three-year day count and pin the start date, because every move below has a deadline measured against it. This is the inbound mirror of the US exit tax, which is also entirely a before-the-date exercise: on the way in you plan before the clock starts, and on the way out you plan before it stops.
Reset Your Basis Before You Arrive
Here is the single most valuable move, and the one people most often get wrong. A nonresident generally pays no US income tax on gains from foreign assets, and no US tax on gains from US-company stock if present under 183 days in the year of sale. So selling appreciated assets to unrelated buyers just before your residency starting date, and then repurchasing them, locks in a fresh, market-value cost basis at zero US cost. When you later sell as a US resident, only the appreciation that happened after you arrived is taxed. Years of built-up foreign gain simply fall out of the US tax base.
The trap is believing this happens on its own. US law does hand an immigrant a market-value basis as of the start date, but only for the future exit tax if you ever give up the status, not for ordinary income tax. Do nothing and you keep your old, often near-zero, basis for every future sale, and you get taxed on the full pre-immigration gain. The affirmative sell-and-repurchase is the only way to get a real income-tax basis reset.
It has to be done asset by asset, because the classes do not behave alike:
- Foreign stock, foreign real estate, foreign business interests. Reset for free. The gain is foreign-source and untaxed to a nonresident.
- US-company stock. Resets tax-free only if you are present under 183 days in the sale year; otherwise the gain can be taxed.
- US real estate. The exception that bites. Selling US property triggers US tax and withholding under the rules for foreign owners of US real estate, so a sale to reset basis costs real money. Our page on FIRPTA withholding on US real estate walks through those rules.
- Foreign mutual funds. The sale doubles as a cleanup, but plan the fund election in your first US year as well (see the traps below).
Two execution points matter. The sale has to be a genuine, arm's-length transaction, not a paper shuffle through an entity you control, or the IRS can collapse it and deny the reset. And you have to document market value at the time, with a real buyer and a real valuation. The modeling behind all of this is income-tax work we co-counsel with an international tax advisor.
Pull Income Into the Nonresident Window
Because your start date flips on worldwide taxation, the same dollar of income can be US-tax-free or fully taxed depending on which side of the date it lands. So where you have a choice, you pull income into the nonresident window.
A dividend from your foreign company paid to you as a nonresident is foreign-source and US-tax-free; paid the day after you become a US person, it is worldwide income on your US return. A foreign-pension lump sum or a deferred-compensation payout triggered before the date is likewise outside the US net; triggered after, it is taxed. If you have gains you actually want realized, taking them now, at the nonresident rate of zero on foreign assets, beats taking them later at resident rates. This coordinates directly with the basis reset above: the same pre-arrival sale that resets basis can also be timed to keep the gain out of the US base entirely.
The Traps That Switch On the Day You Become a US Person
Some assets are perfectly harmless while you are a nonresident and turn punitive the moment you become a US person. Left alone, they can tax you every year on money you never received. Three show up again and again.
- Your foreign company becomes a controlled foreign corporation. A closely held foreign company is not a US problem while you are a nonresident. Once you are a US shareholder, it can become a controlled foreign corporation, which pulls part of its earnings onto your US return each year even if nothing is distributed. The fixes, distributing or repatriating earnings while you are still a nonresident, or restructuring the company, have to be done before the date.
- Your foreign fund becomes a PFIC. A foreign mutual fund or pooled investment can become a passive foreign investment company (a foreign fund the US taxes under a harsh default set of rules, with an interest charge layered on top). You can escape the punitive default by making a specific election in your first US year, and the pre-arrival sale-and-repurchase can serve as a clean reset for the holding.
- Foreign trusts and foreign pensions. A foreign trust you are connected to can start carrying US income and reporting duties. And funding a foreign trust after you become a US person can trigger a deemed sale, taxing built-in gain on the way in, a tax a nonresident's funding never triggers. That timing point is exactly why the trust move in the next section is a before-the-date play.
None of these is a reason to panic and none is a reason to wait. They are a reason to map every foreign company, fund, trust, and pension you hold against the calendar before your start date, usually alongside an international tax advisor who models the numbers.
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Book your free consultThe Foreign-Trust Move and the Five-Year Clock
For a client with real wealth to protect, one of the strongest pre-arrival moves is to irrevocably place assets in a foreign trust that is not treated as owned by any one person (a foreign non-grantor trust), often called a drop-off trust. Done while you are still a nonresident, a completed transfer of foreign-situs property, and of US intangibles like publicly traded stock, sits outside the future US estate net, and the trust itself is taxed like a nonresident, so its non-US income stays outside your future US return. The estate shelter can survive even if the trust is later brought onshore for other reasons.
The catch is a five-year lookback. If you have a residency starting date within five years after funding a foreign trust, US law can treat you as having made the transfer on your start date and re-attribute the trust's worldwide income to you for life. So the conservative plan funds the trust irrevocably more than five years before your residency starting date. Two more rules ride along: fund while you are still a nonresident, because funding a foreign trust after you are a US person can trigger the deemed-sale tax noted above; and if US family members are beneficiaries, distribute income currently rather than letting it pile up, because accumulated income later carries a harsh throwback tax and compounding interest charge when it is finally paid out. And keep it a genuine gift, with no side understanding that you can pull the assets back, or the whole trust can be dragged back into your US estate. This is specialized drafting we co-counsel, and the five-year runway is why we start it early or use the deferral levers below to buy time.
The Estate and Gift Tax Shift: A Different Clock
Income tax is only half the picture, and the estate and gift side runs on a separate clock that surprises people. US estate and gift tax turn on domicile, meaning the place where you live with no present intention of leaving, not on the mechanical residency test that governs income tax. The two diverge constantly. You can be a US income-tax resident, a green-card holder or someone who met the day-count, while you are not yet a US domiciliary, because domicile needs that added intent to stay indefinitely. That gap is a once-only planning window.
Why it matters is a cliff. As a non-domiciliary, the US taxes only your US-situs property at death, and your US estate exemption is a mere $60,000, with no lifetime gift exemption at all. As a US domiciliary, the US taxes your worldwide estate, but you get the full $15 million exemption for 2026. The top rate is 40% either way. Domicile status can swing the result by millions on the same assets.
The play lives in the gap. While you are still a non-domiciliary, you can gift US-company stock and other intangibles, and any non-US property, free of US gift tax, even though that same US stock would be taxed in your estate if you died holding it. Move the appreciated stock and fund the family trusts while the window is open, because once you become domiciled, gifts get throttled to the $19,000 annual exclusion (or $194,000 to a non-citizen spouse). One caution: gifting US real estate or US tangible property during the window does get taxed, so this is a move for intangibles, not for the house. For the full estate-tax picture on each side, see US estate tax for a non-resident alien and estate planning for non-US citizens.
Notice that this is a different deadline from the five-year trust clock. The trust clock wants funding more than five years before your income residency date; the gift-before-domicile clock wants the gift completed before domicile attaches, which can be after your income residency date, during the not-yet-domiciled window. Both have to be run, and they can point to different dates. There is a Florida wrinkle too: the very conduct that establishes Florida domicile for its no-income-tax advantage, buying a homestead, filing a declaration of domicile, moving the family in, is also what fixes US transfer-tax domicile and slams the gift window shut. So the gifts come first, and the domicile checklist comes after.
Can You Push the Residency Date Out?
Sometimes the right move is to buy time, and two levers can push your start date out or keep a marginal year from counting as US residency at all. Both matter most when you need runway for the five-year trust clock.
The first is the closer-connection exception. If you are present under 183 actual days this year, keep a tax home abroad, and have a closer connection to another country, you can stay a nonresident even though the day-count formula would otherwise catch you; you claim it on Form 8840. The second is a treaty tie-breaker: someone who is a resident of two countries can be treated as a nonresident of the US under a US tax treaty's tie-breaker rules, claimed on Form 8833.
There is an important asymmetry to flag. For someone coming in, these levers are clean and helpful. But the choice of immigration vehicle also sets a future exit-tax clock. A green card starts a long-term-resident count, and once you have held the card in at least 8 of 15 years, giving it up can trigger the exit tax, including for a green-card holder who takes exactly that treaty tie-breaker position. A non-immigrant or treaty path does not start that clock, though it can still make you a worldwide taxpayer through the day-count. So taking a green card "to be safe" when a treaty path would serve can set up a tax on the way out that you never needed to face. We run that count before anyone chooses a path. The exit-tax page covers the outbound side in full.
How We Work, and When We Co-Counsel
Pre-immigration planning is cross-border work with a lot of moving pieces, so we are clear about where our role sits. Screening when your US tax clock starts, running the separate domicile question, building the two-clock timeline, and the estate, gift, and Florida-domicile planning are handled here. The deemed-sale and income-tax modeling, the controlled-foreign-corporation and foreign-fund cleanup, and the foreign-trust drafting we co-counsel with an international tax advisor, and any foreign-country tax is handled by qualified foreign counsel. We tell you up front which pieces your matter needs.
Where this meets our Florida practice is the estate and residency side. Florida is the top landing spot for inbound families, and its lack of a state income or estate tax is a real advantage, but only if the transfer-tax moves are sequenced correctly against the domicile clock. Most of this runs remotely, by phone and video, which suits clients who are still abroad, including the many families relocating from Israel. The first and most valuable step is the screen, because it sets every deadline that follows. See the full international tax planning hub →
Frequently Asked Questions
When Do You Become a US Taxpayer?
On your residency starting date, and there are two ways to reach it. The green-card test makes you a US tax resident the first day you are physically present in the US as a lawful permanent resident, so a single landing can start it. The substantial-presence test is a day-counting formula that can make you a US taxpayer with no green card at all: 31 days in the US this year, plus a weighted 183 days across three years, counting this year in full, one-third of last year, and one-sixth of the year before. You are a nonresident until that date and a worldwide US taxpayer from it, so the first year is usually a split, or dual-status, year.
What Is Pre-Immigration Tax Planning?
It is the set of moves you make before your residency starting date, while you are still a nonresident and the US taxes almost none of your foreign income and sits outside your estate for most assets. The window closes on that date. Common moves are resetting the cost basis of appreciated assets, pulling income into the pre-residency period, cleaning up foreign companies and foreign funds that turn punitive the day you become a US person, and, for the right client, funding a foreign trust well ahead of time. It is the inbound mirror of exit-tax planning, which is also a before-the-date exercise.
Can I Step Up My Basis Before Moving to the US?
Yes, but only by acting. A nonresident generally pays no US income tax on the sale of foreign assets, so selling appreciated assets to unrelated parties before your residency starting date and then repurchasing them can lock in a fresh, market-value cost basis at no US cost. When you later sell as a US resident, only the appreciation after you arrived is taxed. The trap is assuming this happens automatically. The law gives an immigrant a market-value basis as of the start date, but only for the future exit tax if you ever leave, not for ordinary income tax. Do nothing and you keep your old, often near-zero, basis and get taxed on the full pre-immigration gain later.
Do I Have to Sell Everything Before Immigrating?
No, and doing so can backfire. The reset works asset by asset. Foreign stock, foreign real estate, and foreign business interests reset for free, because the gain is foreign-source and untaxed to a nonresident. US-company stock can reset tax-free only if you are present under 183 days in the sale year. US real estate is the opposite: selling it triggers US tax and withholding under the rules for foreign owners of US property, so a sale to reset basis costs real money. Foreign mutual funds need their own election in your first US year. Each class needs its own call, which is why the plan is built asset by asset, not by dumping everything.
What Happens to My Foreign Company or Foreign Mutual Fund When I Move?
Both can switch from harmless to punitive on day one. A closely held foreign company that was fine while you were a nonresident can become a controlled foreign corporation once you are a US shareholder, pulling some of its earnings onto your US return every year. A foreign mutual fund or pooled investment can become a passive foreign investment company, which carries a harsh default tax plus an interest charge unless you make a specific election in your first US year. The pre-arrival fixes, distributing earnings, restructuring, or making the right election on time, all have to be set up before your start date, usually with an international tax advisor.
How Does Becoming a US Person Change Estate and Gift Tax?
It changes the base entirely. Estate and gift tax turn on domicile, meaning where you live with no present plan to leave, which is a different and later test than income-tax residency. A non-domiciliary is taxed only on US-situs assets, with a US estate exemption of just $60,000 and zero lifetime gift exemption. A US domiciliary is taxed on worldwide assets, but with the full $15 million exemption for 2026. The top rate is 40% either way. Because you can be a US income-tax resident while not yet a US domiciliary, there is often a narrow window to gift US-company stock and other intangibles free of US gift tax before domicile attaches and throttles gifts to the $19,000 annual exclusion.
Can I Delay Becoming a US Tax Resident?
Sometimes, and a delay can be worth a lot. Two levers can push the date out or drop a marginal year out of residency. The closer-connection exception applies if you are present under 183 actual days this year, keep a tax home abroad, and have a closer connection to another country; you claim it on Form 8840. A treaty tie-breaker can treat a dual resident as a nonresident under a US tax treaty, claimed on Form 8833. Both buy time to finish the plan, which matters most for the five-year foreign-trust clock. One caution: for a long-held green-card holder, the same treaty move can itself count as leaving the US tax system, so it has to be run carefully.
Do You Handle This In-House?
We handle the parts that decide the outcome and are honest about the rest. Screening when your US tax clock starts, running the domicile question, building the two-clock timeline, and the estate, gift, and Florida-domicile planning are handled here. The deemed-sale and income-tax modeling, the foreign-company and foreign-fund cleanup, and the foreign-trust drafting we co-counsel with an international tax advisor, and any foreign-country tax is handled by foreign counsel. We tell you up front which pieces your matter needs before you commit to anything.
Common Situations
The founder moving to Miami with a foreign company. A tech founder plans to relocate to Florida next year, holding appreciated shares in her own foreign company plus a personal portfolio. A pre-arrival plan resets the portfolio basis with real sales before her start date, distributes the company's trapped earnings while she is still a nonresident so it does not become a controlled foreign corporation on day one, and gifts a block of US-listed stock to a family trust during the not-yet-domiciled window, free of US gift tax. What she moves now would be throttled to a $19,000 annual gift once she is domiciled.
The investor-visa immigrant in the backlog. A family in a multi-year investor-visa queue treats the wait as the planning window. Because their residency is still years away, there is time to fund a foreign trust more than five years before the start date, keeping that wealth outside the future US estate and income net, and to reset basis and clean up foreign funds well ahead of the day conditional residency attaches.
The snowbird drifting toward the day-count. A retiree who winters in Florida is edging toward the substantial-presence threshold without intending to become a US taxpayer. Running the three-year day count and, where it fits, claiming the closer-connection exception on Form 8840 keeps him under 183 actual days and out of an accidental residency year, while the domicile analysis confirms his estate stays outside the US net.
Sources of Law
- Residency starting date, substantial-presence and green-card tests, closer-connection and treaty tie-breaker: 26 U.S.C. §7701(b)(1) to (b)(4) and (b)(6) (residency start date; 31-day and weighted 183-day count; first-year election; up to 10 disregarded days; treaty tie-breaker); §7701(b)(3)(B) (closer-connection exception, Form 8840); Form 8833 (treaty position). law.cornell.edu
- Basis reset and nonresident gain sourcing: 26 U.S.C. §865(a) (residence-based sourcing); §871(a)(2) (US-source capital gains of a nonresident present 183 days or more); §877A(h)(2) and Notice 2009-85 (market-value basis on the residency starting date applies for the exit tax only, and excludes US real property, not a general income-tax step-up); §7701(o) (economic-substance and step-transaction limits on a paper reset).
- US real estate held by a foreign owner: 26 U.S.C. §897 and §1445 (FIRPTA: gain taxed as effectively connected income, plus withholding on sale). law.cornell.edu
- Foreign companies, foreign funds, and foreign trusts: 26 U.S.C. §951A and related subpart F (controlled foreign corporations); §§1291 to 1298 (passive foreign investment companies); §679(a)(1), (a)(4), and (c) (five-year pre-immigration foreign-trust lookback and the US-beneficiary presumption); §684 (deemed sale on a US person's transfer to a foreign trust); §§665 to 668 (throwback tax and interest charge on accumulated trust income).
- Estate and gift tax, domicile, and the situs mismatch: Treas. Reg. §20.0-1(b)(1) (estate-tax domicile) and §25.2501-1(b) (gift-tax domicile, same standard); 26 U.S.C. §2101 and §2102(b)(1) (non-resident estate tax and the $13,000 unified credit that shelters $60,000 of US situs, not inflation-indexed); §2103 to §2105 (US-situs property and exclusions); §2104(a) (US-company stock and US real estate are US-situs at death); §2501(a)(2) (a non-resident's gifts of intangibles are outside US gift tax); §1015 (carryover basis on a lifetime gift). 2026 figures: $15,000,000 worldwide exemption; $19,000 annual gift exclusion; $194,000 to a non-citizen spouse. (retrieved 2026-07-16)
Updated on July 16, 2026. Reviewed by Kevin D. Klagge, Esq., Fla. Bar No. 99502. Attorney Kevin Klagge represents families, businesses, and international clients in estate planning and international law, with a focus on Florida legal tools. He litigates estate and business issues in court. This article is general information about US law, not legal or tax advice, and does not create an attorney-client relationship. Pre-immigration planning is specialized; the deemed-sale and income-tax modeling, the foreign-company and foreign-fund cleanup, and the foreign-trust drafting are co-counseled with an international tax advisor, and foreign-country tax is handled by foreign counsel. Federal figures are adjusted periodically and may change. Your result depends on your specific facts.