Dual Citizenship and the U.S.: What New Citizens Should Know

Updated: October 30, 2026

U.S. law doesn't require you to give up your other citizenship when you naturalize, and it doesn't make you choose between the two. The State Department recognizes that dual nationality exists, and you won't be asked to hand in your foreign passport. Whether you keep your original citizenship is decided by your other country's law, not by the United States. Some countries allow dual citizenship, some require notice or permission, and some end your citizenship automatically when you naturalize elsewhere.

The oath says you "renounce" other allegiance. So what?

The Oath of Allegiance begins with a promise to "absolutely and entirely renounce and abjure all allegiance and fidelity to any foreign prince, potentate, state, or sovereignty." Many new citizens worry that this cancels their other citizenship.

In practice, the United States doesn't enforce this renunciation by requiring you to give up your foreign passport or formally leave your other nationality. The oath expresses your primary loyalty to the United States. Your other country decides for itself whether your naturalization affects your status there. Some countries treat the U.S. oath as voluntary renunciation. Most don't.

How your other country's law matters

Countries take roughly three approaches:

Dual citizenship allowed. You keep your citizenship automatically. Many countries in Europe and the Americas take this approach, but rules and details vary.
Allowed with conditions. You may need to apply for permission before naturalizing, register your new citizenship, or keep certain documents current.
Not allowed. Your citizenship ends automatically when you voluntarily acquire another, or you must choose. The State Department notes, for example, that China doesn't recognize dual nationality.

Before you file your N-400, check with your country's embassy or consulate, or its official government website. Laws change, so look for current information, not forum posts from years ago. If keeping your citizenship requires steps before your oath, do them in time.

Travel as a dual citizen

Once you're a U.S. citizen:

Use your U.S. passport to leave and enter the United States. U.S. citizens must do so by law.
You can't use a U.S. visa or ESTA. The State Department warns that dual nationals may not use their foreign passport to apply for ESTA, and such applications are denied or cancelled.
Use your other passport to enter your other country if that country requires it. Many countries require their own citizens to enter on their own passport.
Carry both passports when traveling between your two countries, and make sure the airline sees the right one at each stage.

Consular help abroad

If you're in your other country of citizenship, its authorities may treat you only as their citizen. That can limit the help the U.S. embassy can give you if you're detained or in trouble there. Some countries also impose exit bans or other obligations on their nationals. The State Department publishes country-specific information at travel.state.gov. Check it before traveling, especially to countries with strained relations with the United States.

Military service and other obligations

Your other country may require military service from its citizens, even if you live in the United States. Some allow exemptions for citizens living abroad, others don't. Check before you visit, especially if you're a young man.

Taxes

The United States taxes its citizens on their worldwide income, even if they live abroad. As a dual citizen you must file U.S. tax returns every year if your income meets the filing threshold, and you may have to report foreign bank accounts (FBAR) and foreign assets. Tax treaties and credits often prevent double taxation, but filing is still required. Your other country may tax you too, depending on its rules and where you live. A tax professional with cross-border experience can help.

Can you lose U.S. citizenship by keeping another?

Simply having another citizenship doesn't cause you to lose U.S. citizenship. Under U.S. law, a citizen loses citizenship only by voluntarily performing certain acts, such as formally renouncing at a U.S. embassy, with the intent of giving up U.S. citizenship. Using your other passport to enter your other country, voting in its elections or owning property there doesn't by itself end your U.S. citizenship.

Separately, naturalized citizens can have citizenship revoked (denaturalization) through legal proceedings if it was obtained illegally or by fraud, for example by hiding crimes on the N-400. That's about how you got citizenship, not about dual nationality. It's another reason to answer every question on Form N-400 truthfully.

Proposals to change the rules

Bills to restrict dual citizenship for U.S. citizens have been introduced in Congress. As of this writing, no such restriction has become law, and the current State Department position is the one described above. Check official sources for updates if you're reading this later.

Children and dual citizenship

Children of a naturalizing parent who become U.S. citizens automatically (see citizenship for children and Form N-600) may also keep their other citizenship, depending on that country's law. Children born in the United States to foreign parents are often dual citizens from birth.

The bottom line for applicants

Check your home country's law before you file.
Complete any steps it requires to keep your citizenship.
After the oath, get a U.S. passport (see the after-naturalization checklist).
Always use your U.S. passport for U.S. entry and exit.
Keep filing U.S. taxes, wherever you live.

For the bigger picture of what citizenship gives you compared with a green card, see green card vs. citizenship. For the whole process, start with how to become a U.S. citizen. This article is general information. For your specific situation, check with the authorities of both countries or a lawyer.

Frequently asked questions

Does the U.S. allow dual citizenship?

Yes, in the sense that U.S. law doesn't require you to give up your other citizenship or choose one. Whether you keep the other one depends on the other country's law.

Do I have to hand in my foreign passport at the oath ceremony?

No. You hand in your green card, not your foreign passport. What you do with your foreign passport depends on your other country's rules.

Can I enter the U.S. on my foreign passport after naturalizing?

No. U.S. citizens must use a U.S. passport to enter and leave the United States, even if they also have another passport.

Will I lose my U.S. citizenship if I vote in my other country?

Generally not. Loss of U.S. citizenship requires a voluntary act done with the intention of giving up U.S. citizenship. Voting abroad alone doesn't meet that standard. Check country-specific issues with an attorney.

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Informational article, not legal advice. Civio is not affiliated with USCIS or any government agency; always check current requirements at uscis.gov.