Yes, you can hold dual citizenship in the US. No federal law forces you to pick between American nationality and another country’s, and Supreme Court rulings protect your right to keep both. What the government won’t do is smooth the path: you take on U.S. tax filings for life, specific passport rules at the border, and thinner consular protection in the country whose passport you also carry.
Is Dual Citizenship Actually Legal in the United States?
There is no statute that defines, bans, or explicitly authorizes dual nationality. The State Department’s Foreign Affairs Manual puts it plainly: the U.S. government “recognizes the existence of dual nationality” but “does not encourage it as a matter of policy because of the problems it may cause.”1Department of State. 7 FAM 080 Dual Nationality
Two Supreme Court decisions lock in your right to keep American citizenship even while acquiring or holding another. In Afroyim v. Rusk (1967), the Court held that the Fourteenth Amendment “protect[s] every citizen of this Nation against a congressional forcible destruction of his citizenship” and that no one can lose citizenship unless they “voluntarily relinquish” it.2Cornell Law Institute. Afroyim v. Rusk Vance v. Terrazas (1980) added that the government must also prove you intended to give up your U.S. nationality, by a preponderance of the evidence.3Cornell Law Institute. Vance v. Terrazas
So getting an Irish passport through your grandparents, naturalizing in Japan, or accepting citizenship from a spouse’s country won’t strip your American nationality unless you clearly meant it to. Whether the other country lets you keep its citizenship after you naturalize elsewhere is a separate question governed by that country’s law. The United Kingdom, Canada, and Australia allow it; some countries do not.
Tax Obligations You Cannot Escape
This is the part most people underestimate. The United States is one of only two countries (the other is Eritrea) that taxes citizens on worldwide income regardless of where they live. A U.S. citizen working in London and paying British taxes still owes the IRS a return every year.4Office of the Law Revision Counsel. 26 USC 911 – Citizens or Residents of the United States Living Abroad You can exclude a portion of foreign earnings or claim credits for foreign taxes paid, but you cannot skip filing.
Foreign Account Reporting: FBAR and FATCA
On top of the tax return itself, two separate reporting rules apply to foreign accounts, and both carry heavy penalties.
The Report of Foreign Bank and Financial Accounts (FBAR) is due if your foreign accounts collectively exceed $10,000 at any point during the year. It goes to the Financial Crimes Enforcement Network, not the IRS. A non-willful violation carries a penalty of up to $16,536 per account per year as of 2025, adjusted annually for inflation.5eCFR. 31 CFR 1010.821 – Penalty Adjustment and Table Willful violations can reach the greater of $100,000 or 50% of the account balance.
FATCA is a separate filing on Form 8938, attached to your tax return, if your foreign financial assets cross higher thresholds. For dual citizens living abroad and filing individually, that means more than $200,000 on the last day of the tax year or more than $300,000 at any point during the year. Joint filers face double those amounts.6Internal Revenue Service. Do I Need to File Form 8938, Statement of Specified Foreign Financial Assets Missing the form triggers a separate $10,000 penalty.7eCFR. 26 CFR 1.6038D-8 – Penalties for Failure to Disclose
Social Security and Totalization Agreements
Working abroad can mean paying into two Social Security systems for the same job. The United States has agreements with about 30 countries — including Canada, the United Kingdom, Germany, Japan, and Australia — that eliminate the overlap. Under these totalization agreements, you generally pay into only one country’s system depending on where you work and how long the assignment lasts, and credits from both countries can be combined to help you qualify for benefits.8Social Security Administration. U.S. International Social Security Agreements In a country without an agreement, you can end up paying into both systems with no relief.
Why Tax Treaties Help Less Than You Think
U.S. tax treaties contain a provision called the “saving clause” that lets each country tax its own citizens and residents as if the treaty didn’t exist.9Treasury. United States Model Income Tax Convention 2016 If a treaty exempts certain income from U.S. tax for residents of the other country, you generally can’t claim that exemption as a U.S. citizen living there. Foreign tax credits still prevent double taxation on the same income, but treaty benefits are narrower for Americans than for non-U.S. citizens in the same situation.
Passport Rules at the Border
Federal law requires every U.S. citizen to use a valid U.S. passport when entering or leaving the country.10eCFR. 22 CFR Part 53 – Passport Requirement and Exceptions You cannot present a foreign passport at a U.S. port of entry to slip through as a visitor. Border officers treat you as an American, period.
Most dual citizens carry two passports and switch between them. You use your foreign passport when leaving or entering the other country, to satisfy that country’s rules and avoid visa problems, then present your U.S. passport to the CBP officer when you arrive home.11Office of the Law Revision Counsel. 8 USC 1185 – Travel Control of Citizens and Aliens Let the U.S. passport lapse and you can face delays, secondary screening, or a denied boarding at the gate.
Passing Citizenship to Children Born Abroad
If you’re raising a family overseas, whether your child automatically acquires U.S. citizenship at birth depends on how much time you personally spent in the United States. When one parent is a U.S. citizen and the other is not, the citizen parent must have been physically present in the U.S. for at least five years before the child’s birth, with at least two of those years after turning 14.12USCIS. Chapter 3 – U.S. Citizens at Birth (INA 301 and 309) Time abroad while employed by the U.S. government or military counts toward the requirement.
When both parents are U.S. citizens, only one needs to have resided in the United States or a U.S. possession at some point before the child’s birth, with no minimum duration specified in the statute.13Office of the Law Revision Counsel. 8 USC 1401 – Nationals and Citizens of United States at Birth
These thresholds catch people out. Someone who left the U.S. as a teenager and lived abroad ever since may not have accumulated enough physical presence to pass citizenship to a child born overseas. Some dual citizens plan around this by spending time in the U.S. before starting a family.
Consular Help Is Limited in Your Other Country
If you get into legal trouble in your other country of nationality, U.S. help shrinks. Under international law, when a dual national is inside one of their countries of citizenship, that country has the primary claim and can treat you as its own citizen. U.S. consular protests may simply be ignored.1Department of State. 7 FAM 080 Dual Nationality
The State Department will still try to intervene, but success is not guaranteed. If you’re arrested in the country of your other nationality, that country generally has no obligation to notify the U.S. consulate or grant consular access. Entering on your other country’s passport further reduces the chance local authorities will recognize your American status at all. Weigh this seriously if your other country has a weaker legal system or is in political turmoil.
Security Clearances and Federal Jobs
Dual citizenship isn’t an automatic bar to a clearance, but it will get looked at. Security Executive Agent Directive 4, which governs clearance adjudication across the federal government, states that “the fact that a U.S. citizen is also a citizen of another country is not disqualifying without an objective showing of such conflict or attempt at concealment.”14Office of the Director of National Intelligence. Security Executive Agent Directive 4 – Adjudicative Guidelines What draws scrutiny is whether you’ve exercised the foreign citizenship in ways that suggest a preference for the other country: using its passport to enter the U.S., failing to disclose foreign identity documents, or taking a position in a foreign government.
The State Department evaluates dual-national cases individually, and where the determination is unfavorable, it withdraws the job offer.15U.S. Department of State. Dual Citizenship – Security Clearance Implications The department also generally won’t post employees to a country where they hold citizenship, because the Vienna Convention on Diplomatic Relations doesn’t extend diplomatic immunity to dual nationals in their own country. Intelligence agencies apply the tightest scrutiny, though a willingness to renounce the foreign citizenship can mitigate the concern.
One related obligation: male dual citizens between 18 and 25 must register with the Selective Service System within 30 days of turning 18, even if they live abroad.16Selective Service System. Who Needs to Register Failing to register rarely triggers prosecution but can disqualify you from federal student aid, federal jobs, and (for immigrants) naturalization.17Office of the Law Revision Counsel. 50 USC 3811 – Offenses and Penalties
How You Could Actually Lose U.S. Citizenship
Section 349 of the Immigration and Nationality Act lists the acts that can end U.S. citizenship, but only if performed voluntarily and with the intent to give it up:18Office of the Law Revision Counsel. 8 USC 1481 – Loss of Nationality by Native-Born or Naturalized Citizen
- Serving in a hostile foreign military, or serving as a commissioned or non-commissioned officer in any foreign military.
- Accepting a position in a foreign government if you hold or acquire that country’s nationality, or if the position requires an oath of allegiance.
- Being convicted of treason, attempting to overthrow the U.S. government by force, or conspiring to do so.
- Formally renouncing citizenship before a U.S. consular officer abroad.
Because of Afroyim and Vance v. Terrazas, the government must prove intent. Joining a foreign military in peacetime or taking a routine government job abroad won’t cost you citizenship unless you meant it as a farewell. Agencies presume you intend to keep U.S. citizenship unless you say otherwise.
The Cost of Formal Renunciation
If you do decide to give up U.S. citizenship, you must appear at a U.S. embassy or consulate abroad and go through a formal process. The current administrative fee is $2,350.19Federal Register. Schedule of Fees for Consular Services – Administrative Processing of Request for Certificate of Loss of Nationality Fee The State Department proposed reducing it to $450 in October 2023, but the final rule implementing that reduction has not been confirmed.
The bigger sting is tax. If you qualify as a “covered expatriate,” the IRS treats most of your worldwide assets as if you sold them the day before expatriation and taxes the unrealized gains. You’re a covered expatriate if any of the following apply:
- Your net worth is $2 million or more on the date of expatriation.20Internal Revenue Service. Expatriation Tax
- Your average annual net income tax liability for the five years before expatriation exceeds $211,000 (the 2026 threshold, adjusted annually for inflation).21Internal Revenue Service. Rev. Proc. 2025-32
- You fail to certify that you’ve complied with all federal tax obligations for the previous five years.
The mark-to-market exit tax applies to gains above an exclusion amount indexed for inflation from a base of $600,000. For expatriates with significant investment portfolios, retirement accounts, or real estate, the bill can run into six figures, and it’s due whether or not you’ve actually sold anything. Model the tax consequences well in advance of any renunciation decision.