Married to a Non-American: MFS, Head of Household, or the §6013(g) Election?

The moment you marry a nonresident alien, the IRS takes away your best filing status and hands you the worst one by default. That is not a metaphor. Married filing separately is the fallback the code assigns you, and MFS carries the narrowest brackets, the fastest phaseouts, and a list of disallowed credits long enough to ruin an afternoon. Nobody chooses it on purpose. Yet a large share of Americans married to foreigners file it year after year, because the alternatives are either invisible to them or wrapped in a decision most people are afraid to make. This post is about seeing the alternatives clearly and making that decision on purpose.

The three real options are MFS, head of household, and a joint return built on the §6013(g) election. They are not interchangeable, and the right answer swings hard on two facts: where your spouse's income lives, and whether you have a dependent in the house. Get those two facts on the table first and most of the analysis falls out on its own.

MFS is the default, and the default is expensive.

If you are a U.S. citizen or resident married to a nonresident alien and you do nothing, you file married filing separately. That is the automatic result, not a strategy, and it is the most punitive of the ordinary statuses. The MFS brackets compress the same rates into half the income of a joint filer, the capital loss deduction is capped at $1,500 instead of $3,000 under §1211(b), and a wall of credits simply switches off: no earned income credit, a reduced or eliminated education credit, and no exclusion for Series EE savings bond interest used for education. If either spouse itemizes, the other must itemize too, standard deduction gone.

There is one mercy hiding inside the default. On an MFS return, you report your income, not your spouse's. Your nonresident spouse's foreign salary, their rental in Lisbon, their brokerage account in Singapore, none of it lands on your 1040 as long as it is not U.S.-source and not effectively connected to a U.S. trade or business. For a couple where the American earns modestly and the foreign spouse earns a great deal abroad, MFS is not a punishment at all. It is a firewall. The American pays U.S. tax on the American's income and the foreign income stays outside the U.S. net entirely.

That firewall is the whole reason MFS survives as a rational choice. The question is always whether the rate premium you pay for compressed brackets is smaller than the tax you would owe if you dragged your spouse's worldwide income onto a U.S. return. Sometimes it is. Often it is not.

Head of household is the status people forget they qualify for.

Here is the provision almost nobody married to a foreigner knows about: under §2(b) and the "considered unmarried" rule of §7703(b), a U.S. person married to a nonresident alien can file as head of household without divorcing, without separating, without any drama at all. The code treats you as unmarried for this purpose specifically because your spouse is a nonresident. You still need to clear the ordinary HoH hurdles: you must maintain a household that is the principal home of a qualifying person, typically a child or other qualifying dependent, for more than half the year, and you must pay more than half the cost of keeping up that home.

Head of household is the sweet spot when it applies, because it gives you wider brackets and a larger standard deduction than MFS while keeping your spouse's foreign income entirely off your return. You get most of the firewall benefit of MFS with a materially better rate schedule. For a citizen with a child and a foreign-earning spouse, HoH is very often the quiet winner, and it is the option that gets left on the table most.

The catch is the qualifying person. No child, no other qualifying relative in the home, and you are back to MFS. A childless couple simply does not have this door available, which is why the analysis for them collapses to MFS versus the joint election.

The §6013(g) election trades your spouse's foreign income for joint brackets.

Section 6013(g) lets you elect to treat your nonresident spouse as a U.S. resident for the entire tax year, which unlocks married filing jointly. In exchange, and this is the price nobody should gloss over, your spouse's worldwide income becomes taxable on the U.S. return. The election is a package deal: you get the joint brackets, the full standard deduction, and access to credits MFS denies you, and you accept that your spouse's foreign salary, foreign rental income, and foreign investment income all now sit inside the U.S. tax system.

The election is not free-floating leverage; it comes with strings.

• It applies to worldwide income of both spouses for the whole year, even if the marriage or the residency happened mid-year.
• Once made, it stays in effect for all later years until it is revoked, and once revoked it can never be made again with the same spouse under §6013(g)(4). You get one bite.
• It drags the foreign spouse fully into the U.S. compliance regime: FBAR on FinCEN Form 114 for foreign accounts over the $10,000 aggregate threshold, Form 8938 under FATCA where the thresholds are met, Form 8621 if there is a PFIC (and a foreign mutual fund almost always is one under §1291), and Form 5471 or 3520 if there is a foreign company or trust in the picture.

Whether the election is worth it turns on the tools that offset the newly taxable foreign income. The foreign earned income exclusion under §911 can shelter a meaningful slice of foreign wages, up to $126,500 for 2024 per qualifying person, and the foreign tax credit under §901 can wipe out U.S. tax on income already taxed abroad at a comparable or higher rate. When the foreign spouse lives in a high-tax country, the §901 credit often reduces the marginal U.S. cost of the election toward zero while you keep the joint brackets. When the foreign spouse's home country has low or no income tax, the election can be a straightforward tax increase dressed up as a filing convenience.

I worked with a software engineer, a U.S. citizen, married to a German national who earned roughly €95,000 a year in Munich and had never set foot in the U.S. tax system. They had filed MFS for four years on the advice of a preparer who never asked the follow-up questions. Germany's effective rate on her salary ran higher than the U.S. rate would, so the §6013(g) election combined with a §901 foreign tax credit cost them almost nothing in additional U.S. tax while moving the American from MFS brackets to joint brackets. The catch surfaced in her portfolio: two German fund holdings were PFICs, and cleaning up the Form 8621 treatment under §1291 took more work than the return itself. Net result was still a four-figure annual savings, but the compliance load was real, and they went in knowing it. That is the honest shape of this election. It is often worth it, and it is never weightless.

So which one wins.

There is no status that wins for everyone, and any preparer who names one before asking about your spouse's income and your dependents is guessing. The decision comes down to three questions asked in order. Do you have a qualifying person in the home? If yes, head of household is usually the floor to beat, because it improves your brackets while keeping foreign income out. Is your spouse's foreign income large and taxed heavily abroad? If yes, the §6013(g) election plus a §901 credit often beats everything, because you capture joint brackets at little marginal cost. Is your spouse's foreign income large and lightly taxed, or is your own income the smaller number? Then MFS as a firewall may quietly be the cheapest answer despite its ugly brackets.

Run all three. The gap between the best and worst outcome for a cross-border couple is routinely thousands of dollars a year, and the default is almost never the best. If your situation involves foreign entities, trusts, or PFICs, the compliance cost of the election belongs in the math too, and that is a conversation to have before you sign, not after. As always, the right answer depends on your specific facts and the countries involved, so confirm the current-year figures and consult a professional before you elect.

Sources

• IRC §6013(g) (election to treat nonresident spouse as resident) and §6013(g)(4) (termination and one-time bar on re-election)
• IRC §2(b) (head of household) and §7703(b) ("considered unmarried" rules)
• IRC §1211(b) (capital loss limitation for MFS)
• IRC §911 (foreign earned income exclusion; $126,500 exclusion amount for 2024)
• IRC §901 (foreign tax credit)
• IRC §1291 (PFIC excess distribution regime)
• FinCEN Form 114 (FBAR), $10,000 aggregate reporting threshold
• Form 8938 (FATCA reporting under IRC §6038D)
• Form 8621 (PFIC reporting)
• Forms 5471 and 3520 (foreign corporation and foreign trust reporting)