Your 401(k) company stock, NUA and the move to Spain

The client worked at the same company for thirty-one years. He has a 401(k) worth $1.4 million, and about $600,000 of it is not a fund at all — it is stock in the company he worked for, bought a paycheque at a time since the Reagan administration. His financial adviser in Ohio has been telling him for years that this line is special, that there is a manoeuvre available on it that is worth a great deal of money, and that he must not do anything careless with it.

The adviser is right. The manoeuvre is real, it is in the Internal Revenue Code, and for a thirty-year employee it can be worth six figures.

Then the client mentions, at the end of the call, that he and his wife are moving to Málaga in the spring.

This page is about what happens next, and it is not the page we expected to write. We assumed the answer would be the usual one — that the American planning still works, only a bit less well, and that the job is to trim the edges. It is not. The American rule and the Spanish rule are both keyed to the same single physical fact: whether the shares pass through your hands. And they reward the opposite answer. Not by accident of drafting, and not in a grey area. By construction.

"Almost everything in an American retirement file is a question of how much. This one is a question of which. There are two doors, both of them legitimate, and the client has to walk through one of them before he lands. What frightens me is not that the choice is hard. It is that in America the choice looks like a technicality, so it gets made by default, months before anyone thinks to ask what Spain will make of it."

The line on the statement that is not like the others

Company stock inside a 401(k) is an ordinary-looking thing with an extraordinary tax history attached to it, and the history is invisible on the statement.

The statement shows a value. What it does not show — what lives in the plan's records and nowhere else — is what the shares cost when they went in. For an employee who bought stock at $4 a share in 1994 and watched it become $90, those two numbers are separated by an entire career. American law cares enormously about the gap between them. It has a name for it: net unrealized appreciation, universally shortened to NUA.

Everything else in that same 401(k) — the index funds, the target-date fund, the bond sleeve — has no such history. Inside a qualified plan, cost basis is normally meaningless: the money went in untaxed, it grows untaxed, and every dollar that comes out is ordinary income. That is the deal, and it is the deal for the other $800,000 in this client's account. The company stock is the one asset in the plan for which the plan's own purchase price still matters.

Hold on to that, because it is the hinge of this entire page: NUA is a rule about a number that only exists inside an American retirement plan. Nothing in Spanish tax law has ever needed that number. Nothing in Spanish tax law has a place to put it.

What NUA actually is

The rule sits in section 402(e)(4) of the Internal Revenue Code, and its operative sentence is short enough to quote. Section 402(e)(4)(B) provides that in the case of a lump sum distribution which includes employer securities, there shall be excluded from gross income the net unrealized appreciation attributable to the employer securities.

Unpack what that buys you. You take the shares out of the plan — actually out, in kind, into a normal taxable brokerage account in your own name. In the year you do it, America taxes you as ordinary income on the plan's cost basis only: on the $4 a share, not the $90. The remaining $86 a share, the NUA, is excluded from gross income that year. It is not taxed until you sell the shares.

And when you do sell, the Treasury regulation and the ruling that has applied it since 1981 treat that appreciation as gain from the sale or exchange of a capital asset held for more than one year — regardless of how long the plan actually held the shares, and regardless of how long you have held them since. You can distribute the stock on a Monday, sell it on the Tuesday, and the NUA is still long-term capital gain. The IRS has said explicitly that the actual period the security was held by the plan need not even be calculated. Any further appreciation after the distribution is a different matter: that one follows your real holding period in the ordinary way.

So the American arithmetic is: a small slice taxed now at ordinary rates, a large slice taxed later at capital-gains rates, and the taxpayer chooses when "later" is. For a long-tenured employee with a low basis this is one of the most valuable single elections available in American retirement planning. There is a reason the adviser in Ohio keeps mentioning it.

Two conditions matter for what follows. First, it must be a lump-sum distribution, which the IRS defines tightly: the distribution, within a single tax year, of the participant's entire balance from all of the employer's qualified plans of one kind — pension, profit-sharing, or stock bonus plans — and paid because of one of four triggering events: the participant's death, the participant reaching age 59½, separation from service, or, for a self-employed individual, total and permanent disability.

Second — and this is the one that will matter most — a rollover destroys it. The IRS states the consequence without qualification: if you do a rollover, the regular IRA distribution rules apply to any later distributions, and you cannot use the special tax treatment rules for lump sums. Roll the company stock into an IRA and the NUA is gone. Not deferred. Gone. The basis history evaporates and those shares become what everything else in an IRA is: ordinary income on the way out, every dollar of it, forever.

The treaty names your plan by name

Now cross the Atlantic, and start with the good news, because there is some and it is better than most people realise.

Article 20.1(a) of the US–Spain double tax treaty provides that pensions and other similar remuneration derived by a resident of a Contracting State who is the beneficial owner, by reason of past employment, may be taxed only in that State. You live in Spain; Spain taxes your plan. That is the baseline, and our page on how US retirement income is taxed in Spain works through it in general.

But article 20.5 adds something more specific and more useful. Where an individual resident in one State is a member, beneficiary or participant in a pension fund resident in the other, income derived from the pension fund may be taxed as that individual's income only when, and to the extent that, it is paid to or for the benefit of that individual from the pension fund — and, the article goes on in parentheses, and is not transferred to another pension fund in that Contracting State.

Read that twice. It is a deferral written into the treaty itself. While the money stays inside a US pension fund, Spain does not tax it, however long you have been resident in Málaga and however much the account has grown. And moving it from one US pension fund to another US pension fund is expressly carved out: that is not a payment to you, so Spain still waits.

Which raises the question of what counts as a "pension fund" — and here the treaty is unusually generous and unusually specific. Article 3.1(j)(ii) gives the general definition, and the Memorandum of Understanding to the 2013 Protocol, published in the BOE on 23 October 2019, spells out the American list: trusts providing pensions through a plan qualified under IRC §401(a) (which includes §401(k) plans), profit sharing or stock bonus plans, §403(a) qualified annuity plans, §403(b) plans, §408 IRA trusts, §408A Roth IRAs, §408(p) SIMPLE accounts, §408(k) simplified employee pension trusts, §457(g) trusts providing benefits through a §457(b) plan, and the federal Thrift Savings Fund.

Two safe harbours, one door, opposite directions

Spain's Directorate-General for Taxes addressed this territory directly in binding ruling V0251-25, of 5 March 2025. A retired Spanish tax resident held a US employment-linked plan — in fact a profit-sharing plan — and wanted to know whether he could move the funds to an IRA in the United States, or to a Spanish pension plan, without tax consequences.

The answer has three parts, and they are worth having precisely.

One. If the economic rights are transferred directly to another US pension fund — an IRA, for instance — without the participant receiving any amount, and provided both fall within the treaty's definition, the participant is not subject to Spanish tax on that transfer. Clean. Blessed. In writing.

Two. If the transfer is not made directly, or if the economic rights are received by the taxpayer even transitorily before being paid into another plan, there is Spanish tax. The sixty-day indirect rollover, that familiar American convenience, does not survive the crossing. Touching the money is the event.

Three. If the destination is a Spanish pension plan, there is no mechanism at all. The tax-free mobilisation permitted by the twenty-second additional provision of the LIRPF runs only between social-welfare systems regulated in Spain or under EU law, and an American plan is neither. So the "just move it to a Spanish plan when you get here" idea, which clients raise almost every time, is not a partial answer. It is not an answer.

And where Spanish tax does arise, the ruling is explicit about what it is: the amounts are employment income under article 17.1 LIRPF and are integrated into the general taxable base — the salary scale, not the savings scale. The special regime for Spanish pension plans does not apply. Neither does the 40% reduction in article 17.2.a)3ª and the twelfth transitional provision, because that relief attaches to plans regulated under Spanish law and an American plan is not one.

Now put the two systems' safe harbours next to each other.

Spain's safe harbour is the direct trustee-to-trustee transfer to a US IRA — the money must not touch your hands.

America's break requires the shares to be distributed to you in kind — the shares must touch your hands.

One number, two signs

Suppose the client goes through the American door: he separates from service, takes the lump-sum distribution, and the shares land in a taxable brokerage account. He is already a Spanish tax resident when he does it — more on why that is the realistic case in a moment.

America taxes the cost basis. Spain taxes… what?

The DGT's language in V0251-25 is worth reading literally: el importe de los derechos económicos of the American pension plan must be computed as gross employment income in the general taxable base. The amount of the economic rights. Not a cost figure — the amount. And article 17.1 LIRPF, which the ruling quotes, defines employment income as all consideration or benefits, whatever their denomination or nature, in cash or in kind, deriving directly or indirectly from personal work or the employment relationship. In cash or in kind: the fact that what arrives is 6,700 shares rather than a wire transfer does not push it outside the article.

So the reading that follows from the authority we have is that Spain looks at what came out of the plan and taxes the lot, at general rates, in the year it came out. And the gap between what America taxed and what Spain taxed is exactly the NUA — which is to say, exactly the number the American rule went to the trouble of excluding.

Notice why this happens, because it is not the usual story of two countries disagreeing. Spain has not looked at the basis figure and decided it is wrong. Spain has no concept the figure could occupy. "What the plan paid for the shares" is not a category in the LIRPF; it is an artefact of a rule written in Washington to solve a problem that only exists in a system where employer stock sits inside qualified plans. America splits one distribution into two numbers. Spain can only see the total — and there is nothing perverse about that, because the total is the only thing that actually left the plan.

We want to be careful and say plainly what is settled and what is not. Article 17.1, the general base, no 40% reduction, no exempt mobilisation to a Spanish plan: that is what the DGT ruled, on a US employment-linked plan, and it is binding. What we have not seen is the Directorate-General ruling squarely on an in-kind distribution of employer securities with an NUA split reported in box 6. A different reading is conceivable — one that somehow imports the American bifurcation — but nobody has shown us the Spanish hook it would hang on, and the burden is on that argument, not on this one. Have it confirmed in writing for your own facts before you rely on either. What we will not do is pretend the point is settled when it is not, or pretend it is open when the authority we have points one way.

The two doors, side by side

Same client, same shares, same year. Only the door changes.

	Door A — direct rollover to a US IRA	Door B — NUA lump-sum distribution
Do the shares touch your hands?	No. Trustee to trustee.	Yes. That is the whole point.
US tax in the year of the move	None. The rollover is not a taxable event.	Ordinary income on the plan's cost basis. NUA excluded from gross income under §402(e)(4)(B).
Spanish tax in that year	None — article 20.5 of the treaty, confirmed by DGT V0251-25 for a direct transfer with no receipt.	On the reading above: the full amount that left the plan, as employment income, article 17.1 LIRPF, general base.
What happens to NUA	Destroyed. Permanently. The IRS is explicit that after a rollover the lump-sum rules are unavailable.	Preserved. Long-term capital gain when sold, whatever the holding period.
Tax on later withdrawals	Spanish employment income, general base, on every dollar — with the timing entirely in your control.	US long-term capital gains on the NUA when you sell. Spanish treatment of that later sale depends on the acquisition value question below.
Where the asset then sits	Inside a US pension fund named in the treaty, still sheltered by article 20.5.	In a taxable brokerage account, outside the treaty's pension perimeter entirely.
Practical friction	Low. The plan administrator does this every day.	Mandatory 20% withholding applies to most taxable lump sums paid directly to you; the cash to cover it has to come from somewhere.

Look at the last two rows of Door B together, because they are the part nobody prices. The NUA distribution does not merely create a tax bill. It relocates the asset from inside the one structure the treaty names and protects to outside it, permanently, on the same afternoon.

The years that never meet

Regular readers of this site will recognise what comes next. Our page on US savings bonds set out that the cross-border trap has two doors: the first is an asset America taxes at zero, so there is no foreign tax credit to have; the second is two countries taxing the same money in different years, so there is no year in which both bills exist to be set against each other.

Company stock with NUA walks through both doors at once, which is something we have not seen another asset do.

Year one. The distribution. America taxes the basis. Spain — on the reading above — taxes the whole amount, as employment income, at general rates. Spain's taxing right under article 20.1(a) is exclusive, and the DGT says so in terms: from Spain's side no existirá doble imposición que corregir, there is no double taxation for Spain to correct. It is the United States, under the saving clause in article 1.3 and the relief article 24.2, that must give the credit. But America only taxed the basis, so the American tax available to be relieved that year is a fraction of the Spanish bill.

Year five. You sell. America taxes the NUA as long-term capital gain — the rule working exactly as designed. And Spain, having already taxed that value as employment income four years ago, would logically treat the shares as acquired at their value on the distribution date, so there may be little or no Spanish gain left to tax. Which means: little or no Spanish tax in year five for the American credit to bite on.

Two countries. Two ordinary rules. One asset. And the relief machinery, which is built to net two bills against each other within a single year and a single category, is asked to bridge a four-year gap between a Spanish employment-income bill and an American capital-gains bill. It is not obvious that it can. Excess credits can be carried, but they are tracked in separate baskets and separate years, and the two halves of this transaction land in different ones.

We are deliberately not going to tell you that you will be taxed twice, because that overstates it and it depends on facts we cannot see from here. What we will tell you is that the mismatch is real, that it is structural rather than a matter of anyone's error, and that the only responsible thing to do with it is to model it in dollars and euros, on your actual basis, before you elect — not after, because there is no after. And note the second-order problem: the Spanish acquisition value of the shares after a distribution taxed as employment income is precisely the kind of point that should be settled in writing rather than assumed, because the alternative reading — a carried-over basis — would produce a result so harsh that no one would believe it until it arrived.

The window does not close — it follows you

Here is where most clients relax, and where they should not.

The natural assumption is that this is a decision you make on your last day at work, in America, as an American, and that by the time Spain is on the table the moment has passed. That would at least be tidy. It is not what the rules say.

The triggering events for a lump-sum distribution — death, reaching 59½, separation from service, disability for the self-employed — are events, not deadlines. Nothing requires you to act on them that year. A man who retires at 62 in Cincinnati, leaves the 401(k) exactly where it is, moves to Málaga at 65 and does the NUA distribution at 67 has, so far as the American rule is concerned, done nothing wrong: the triggering event happened, he has taken no distribution since that would use it up, and he distributes his entire balance from the employer's plans within a single tax year. The election is still there.

It is still there, and he is now a Spanish tax resident, and he does not know that the second fact has anything to do with the first.

The same logic runs the other way, which is the part worth planning around. If the analysis says NUA is worth taking, the year to take it is a year in which you are not a Spanish tax resident — which, given that Spanish residence generally turns on spending more than 183 days of the calendar year in Spain, is a question about a calendar and a boarding pass as much as about tax. That interacts directly with the timing questions our page on leaving Spain deals with from the other side, and it is exactly the kind of thing that is cheap to arrange twelve months out and impossible to arrange in arrears.

Modelo 720 and wealth tax: the asset changes shelf

The NUA distribution does something to your reporting obligations that is easy to miss because it happens silently and on the same day.

Before: the shares sit inside a US qualified plan. Whatever view one takes of how a 401(k) should be reported on Modelo 720 — and it is a genuinely contested area, wrapped up in whether a pension right that is not yet payable is a reportable asset at all — the question is at least arguable, and the wrapper is doing work for you.

After: the shares sit in a taxable brokerage account in your own name. There is nothing contested about that. Listed foreign securities held in an account abroad are squarely within the reporting categories, and squarely within the base for wealth tax and the solidarity levy that sits above it.

So the transaction takes an asset out of a category where you might have had an argument and puts it into one where you certainly do not. That may be perfectly fine — clarity has its own value, and there are worse outcomes than knowing which box you are in. But it should be a decision, not a side effect. And the deadline that follows is not negotiable: the obligation attaches to the year, not to the year you notice.

What the consulate sees

Our page on proving income for the non-lucrative visa sets out the three words a consular officer is reading for: funds that are sufficient, recurring, and available. Test an NUA distribution against them.

Sufficient? Spectacularly, for one year. A $600,000 event will clear any income threshold ever written.

Recurring? No — and not merely "not usually". A lump-sum distribution is by definition the distribution of your entire balance within a single tax year, and the NUA election is a once-per-triggering-event manoeuvre. It is the least recurring thing in your file. A consular officer who reads the 1099-R correctly sees a one-off, and a one-off is the thing the non-lucrative visa is least interested in, because the visa is a bet on year five as much as year one.

Available? Yes, but note what is left afterwards. The shares. NUA only makes sense where the position is large and the basis is low, which means the client who benefits most is by definition the client holding a concentrated single-company position — thirty years of one employer's stock. What the file then shows is not an income stream. It is one company's dividend policy, and a bet.

There is a further wrinkle that catches renewals rather than first applications. In the year of the distribution your Spanish return may show an enormous rendimiento del trabajo — an employment-income figure, on the general scale — that corresponds to no salary, no pension payment and no money you can spend, because what you received was stock. Anyone reading that return without the American context will misread it, and the American context is the part that does not travel.

None of which makes NUA wrong. It makes it a transaction that has to be sequenced against the visa rather than run alongside it, which is the same conclusion our page on using a 401(k) or IRA as proof of income reaches from the other direction: the plan is a fine basis for an application, but what you do to the plan and when is part of the application whether you meant it to be or not.

Three documents, before anything else

Before any modelling, and long before any election, we ask for three things. All of them already exist. Between them they decide this page.

1. The plan's cost basis in the employer securities, in writing, from the administrator. Not an estimate, not the adviser's spreadsheet — the number the plan will put on the 1099-R. Everything on this page is a function of the gap between that number and today's market value. If the gap is small, this whole subject may be a footnote and the decision is easy. If it is thirty years wide, it is the largest single item in the file and it outranks the visa.

2. The date of the triggering event, and every distribution taken since. The eligibility question is technical and unforgiving: a lump-sum distribution is the entire balance from all of the employer's plans of one kind, within one tax year, following a qualifying event. A single small withdrawal in the wrong year can matter. This is a records question with a yes-or-no answer, and it is free to establish.

3. Your Spanish residence dates — the real ones. Arrival, days present, the year the 183-day count is met, and what has already been filed. This is not a formality: it is the variable that decides which of the two doors is even available at a survivable price, and it is the only one of the three that you can still change.

With those on the table the analysis is usually short, and it usually resolves to a sequence rather than a verdict: not whether NUA, but in which tax year, and in which country's calendar, and with the visa timed around it. That is a conversation worth having a year early. It is not a conversation that can be had at all once the shares have left the plan, because the one thing both systems agree on is that the door only opens once.

Sources reviewed July 2026: IRC §402(e)(4)(A), (B) and (C) (on a lump sum distribution which includes employer securities, the net unrealized appreciation attributable to those securities is excluded from gross income); Treas. Reg. §1.402(a)-1(b)(1)(i) (net unrealized appreciation not included in the distributee's basis at the time of distribution is treated as gain from the sale or exchange of a capital asset, to the extent realized in a subsequent taxable transaction) and Rev. Rul. 81-122, 1981-1 C.B. 202 (applying that treatment on a more-than-one-year basis); IRS Notice 98-24 (the actual period an employer security was held by the qualified plan need not be calculated; further appreciation after distribution follows the distributee's actual holding period); IRS Topic no. 412, Lump-sum distributions (last reviewed 16 September 2025) for the definition of a lump-sum distribution — the distribution within a single tax year of the participant's entire balance from all of the employer's qualified plans of one kind, paid because of death, after age 59½, on separation from service, or on total and permanent disability of a self-employed individual — for the reporting of net unrealized appreciation in box 6 of Form 1099-R, for the statement that if you do a rollover the regular IRA distribution rules apply to later distributions and the special lump-sum treatment is unavailable, and for the 20% mandatory withholding on most taxable lump sums paid directly to the participant; IRS Publication 575, Pension and Annuity Income, and the instructions to Form 4972. Convenio entre el Reino de España y los Estados Unidos de América para evitar la doble imposición, Madrid, 22 February 1990, as modified by the Protocol and Memorandum of Understanding of 14 January 2013 (BOE of 23 October 2019): article 20.1(a) (pensions by reason of past employment taxable only in the State of residence), article 20.5 (income from a pension fund taxable as the individual's income only when and to the extent paid to or for the benefit of that individual from the fund, and not transferred to another pension fund in that Contracting State), article 3.1(j)(ii) and paragraph 3 of the Memorandum (the US list of pension funds, expressly including §401(a) qualified plans and §401(k) plans, profit sharing and stock bonus plans, §403(a) and §403(b) plans, §408 IRA trusts, §408A Roth IRAs, §408(p) SIMPLE and §408(k) SEP trusts, §457(g) trusts and the Thrift Savings Fund), article 1.3 (saving clause) and article 24.2(a) (United States relief for Spanish income tax). Consulta vinculante DGT V0251-25, of 5 March 2025 (direct transfer of economic rights to another US pension fund without receipt by the participant does not give rise to Spanish taxation; receipt by the taxpayer, even transitorily, does; the twenty-second additional provision of the LIRPF permits tax-free mobilisation only between social-welfare systems regulated in Spain or under EU law, so no exempt transfer to a Spanish pension plan exists; amounts received are gross employment income under article 17.1 LIRPF integrated into the general taxable base, with article 17.2.a)3ª and the twelfth transitional provision inapplicable; and Spain having exclusive taxing rights, there is no double taxation for Spain to correct), issued with binding effect under article 89.1 of Ley 58/2003. Articles 2, 9 and 17.1 of Ley 35/2006 del IRPF (worldwide taxation of Spanish residents; employment income comprising all consideration or benefits, whatever their denomination or nature, in cash or in kind, deriving directly or indirectly from personal work); Ley 19/1991 del Impuesto sobre el Patrimonio and AEAT guidance on Modelo 720 reportable categories, valuation and deadlines. General information only, and not legal, tax, immigration or US tax advice. In particular: we have not seen the Directorate-General for Taxes rule squarely on an in-kind distribution of employer securities carrying net unrealized appreciation reported in box 6 of a Form 1099-R, and the reading set out on this page — that the full amount leaving the plan is employment income in the general base — is our reading of the authority that exists and not a settled point; the Spanish acquisition value of shares received in such a distribution, the availability, basket and carryover mechanics of United States foreign tax credits across mismatched years and categories, the Modelo 720 and wealth tax treatment of a US qualified plan and of the securities after distribution, the eligibility of any particular distribution as a lump-sum distribution, and the consular treatment of a one-off distribution as proof of means must each be confirmed for your own facts, in writing, with Spanish and US advisers before you rely on them or make any election.