401(k), IRA and Roth in Spain: what the treaty protects

Traditional 401(k) and IRA: predictable, and mostly Spain's

Start with the good news, because it is the larger part of most balance sheets. Under the US–Spain treaty, distributions from private pension arrangements are generally taxable in the country of residence. For a Spanish tax resident, that means a 401(k) or traditional IRA withdrawal is Spanish income, taxed on the progressive scale as employment-type income rather than at savings rates — softened by the over-65 and over-75 allowances that make Spanish retirement taxation gentler than its reputation.

The United States, taxing by citizenship, will also want to see the distribution on your Form 1040. The overlap is resolved with foreign tax credits, and because Spanish rates on a meaningful withdrawal usually exceed the US federal rate, the practical outcome is that Spain collects and the US credits. Two consequences follow. Withdrawals are best modelled against Spain's brackets, not America's — a large one-off distribution that would sit comfortably in a 22% US bracket can climb into Spanish rates above 40%. And the timing tool most people forget still applies: a distribution taken before triggering Spanish residence, under the 183-day rule, never enters the Spanish system at all.

The Roth problem nobody warns you about

Here is where the map stops being comfortable. A Roth works because the United States made a deal with you: tax paid going in, nothing owed coming out. That deal binds the IRS. It does not bind Spain, which has no domestic equivalent of a Roth and no binding published doctrine that recognises its tax-free character.

The prevailing view among cross-border advisers is that Spain may treat Roth distributions — or at least the accumulated growth — as ordinary taxable income. And the sting is structural: because the US correctly taxes nothing on a qualified Roth distribution, there is no US tax to credit against the Spanish bill. The relief machinery that neutralises double taxation everywhere else in this article simply has nothing to work with. A retirement account built specifically to be tax-free can become one of the few genuinely unrelieved tax exposures an American faces in Spain.

Two caveats, in both directions. This treatment is unsettled rather than decided — practice varies, some advisers argue the treaty's pension article should extend protection, and no reader should treat the pessimistic reading as certain. But planning against the pessimistic reading is cheap and planning against the optimistic one is not, which is why the standard advice is to model Roth conversions and withdrawals before becoming Spanish resident, and to get a written professional opinion if a Roth is a large share of your net worth. This is the single most valuable question to bring to a cross-border adviser — not one to settle from a forum thread, including this one.

The investing squeeze: PFICs on one side, PRIIPs on the other

Americans in Spain discover a trap that has nothing to do with Spanish tax and everything to do with being American in Europe. Buy a Spanish or European fund or ETF and, for US purposes, you have bought a PFIC — a passive foreign investment company — which drags you into the punitive excess-distribution regime, annual Form 8621 filings, and effective rates that can exceed the value of the gain itself. The rational response is to avoid European funds entirely.

Then the other jaw closes: EU investor-protection rules (PRIIPs) require a key information document that US fund providers do not produce, so most European brokers will not sell you a US-domiciled ETF. The result is an American resident in Spain who can be effectively locked out of both fund markets at once.

The practical workarounds are well worn: keep a US brokerage account open where the provider permits non-resident address holders, hold individual securities rather than funds, or use US-domiciled ETFs through brokers that accommodate US persons abroad under the professional-investor route. Whatever the route, the fund you casually buy from a Spanish bank app is usually the expensive option. On the Spanish side, ordinary residents also report those foreign accounts on form 720 above €50,000 per category — a filing the Beckham regime exempts you from.

Where the Beckham regime changes the picture

For the six years of the special regime, only Spanish-source income is taxed — which pushes US retirement distributions and foreign investment income outside Spanish scope, and removes the form 720 obligation with them. For a mid-career American with a large 401(k) and an unsettled Roth question, this is worth considerably more than the headline flat 24% on salary that dominates the crossover discussion.

The corollary matters just as much: the regime ends. A Roth conversion, a large distribution or a portfolio restructuring is dramatically cheaper inside the six-year window than in year seven, when worldwide taxation resumes and the Spanish brackets apply to everything. Treat the window as a planning runway rather than a discount on salary, and its real value shows up.

The analysis

The pattern across all three accounts is the same: the United States and Spain each have a coherent system, and the friction lives entirely in the seams between them. Traditional accounts pass through the seam cleanly because both countries agree on what a pension is. The Roth falls into the gap because only one country has the concept. Funds fall into a gap made by two regulators who never intended to interact. Nothing here is a loophole to exploit or a scandal to denounce — it is the ordinary cost of two mature systems meeting at an angle.

Which suggests the honest planning rule for Americans considering Spain. Model the sequence before the rates: what is drawn before residence, what is converted inside the Beckham window, what is restructured before the first form 720. The Spanish tax bill on a well-sequenced American retirement is unremarkable — the Spanish over-65 allowances and this site's calculator will show you an effective rate most Americans find reasonable. The bill on a badly sequenced one is not a rate problem at all: it is a calendar problem that arrived too late to fix.