German and American dual citizenship: what applies to both passports

For decades, Germans who had put down roots in America and couldn't get a retention permit faced a choice: keep the Green Card and stay German, or become a US citizen and lose the German passport. Many put that decision off for years. Today you no longer have to choose. What matters is the right route to the second passport and a clear view of the duties that come with the American one.

Can I take American citizenship as a German?

Yes. On 27 June 2024 the Act to Modernise Nationality Law (Gesetz zur Modernisierung des Staatsangehörigkeitsrechts) came into force. The German Federal Foreign Office sums up the effect in one sentence: anyone who acquires a foreign nationality on application no longer loses their German one. A retention permit (Beibehaltungsgenehmigung) is no longer required. That applies to the US just as it does to every other country.

As an adult, you can now lose German citizenship in only three ways. Section 17(1) of the Nationality Act (Staatsangehörigkeitsgesetz, StAG) lists them:

1. renunciation under Section 26 StAG,
2. voluntarily joining the armed forces of another state whose nationality you hold, without the consent of the Ministry of Defence, as well as taking part in combat for a terrorist organisation abroad, under Section 28 StAG,
3. the withdrawal of an unlawful administrative act under Section 35 StAG.

Naturalisation in the US is not on that list. How the reform works as a whole, and what applies to older cases before 27 June 2024, is explained in the core article on dual citizenship for Germans.

The Oath of Allegiance: why it doesn't cost you your German passport

What worries many Germans in America is the wording of the oath. In the Oath of Allegiance, every new US citizen swears to absolutely and entirely renounce all allegiance to any foreign state of which they have been a citizen. That sounds like renunciation. Under German law, it isn't.

Renouncing German citizenship under Section 26 StAG requires a written declaration, needs the approval of the German nationality authority, and only takes effect once the certificate of renunciation is handed over. An oath in an American courtroom meets none of these conditions. Germany decides for itself who is German, not the text of a foreign ceremony.

What US law says about dual citizenship

On the American side the position is just as clear, only from a different direction. US law doesn't force its citizens to choose one passport. The key provision is 8 U.S.C. 1481: a US citizen loses citizenship only through certain acts carried out voluntarily and with the intention of giving up US nationality.

Those acts do include naturalising in another country on your own application from the age of 18. But it only costs you the American passport if that exact intention lies behind it. An American who naturalises in Germany to hold both passports has no such intention. The law is clear on this point: whoever claims a loss has to prove it.

What this means for you: both countries only let you go if you want them to. And as long as you hold their nationality, both treat you as their own citizen, with all the rights and duties that go with it.

Four routes to German and American dual citizenship

Whether you're already German or already American, whether it's about you or your child: there are four typical routes to both passports.

Birth in the US

Anyone born in the United States and subject to its jurisdiction is a US citizen from birth under 8 U.S.C. 1401(a). If the child has a German parent, it also becomes German at birth under Section 4(1) StAG. Two passports from day one: birth on American soil is the passport you lay in your child's cradle. How parents plan this route is covered in Child born in the US.

There's one trap for families who have lived abroad for some time. Under Section 4(4) StAG, a child born abroad does not automatically become German if the German parent was themselves born abroad after 31 December 1999 and is habitually resident there. German citizenship is saved if registration in the German birth register is applied for within one year of the birth. It's enough for the application to reach the German mission abroad in time. How this works in practice is shown in Born abroad: how your child also gets German citizenship.

Child of an American parent, born in Germany

It works the other way round too. If one parent is American and the other isn't, a child born outside the US becomes a US citizen under 8 U.S.C. 1401(g) if the American parent was physically present in the US for a total of at least five years before the birth, at least two of them after their 14th birthday. A German parent also passes German citizenship to the child under Section 4 StAG. Many German Americans have children with two passports this way without ever giving it a thought.

Naturalising in the US as a German

The classic route runs through the Green Card. Under the requirements of the immigration authority USCIS, you usually need:

• at least five years as a permanent resident,
• five years of continuous residence in the US before applying,
• at least 30 months of physical presence within those five years,
• at least three months of residence in the state or district where you apply,
• a basic knowledge of English and of American history and civics.

If you're married to a US citizen, the period is shorter: three years as a permanent resident living in marital union, with at least 18 months of physical presence in the US. The path from Green Card holder to US citizen, seen from the second passport angle, is described in USA: from Green Card holder to US citizen. The procedure itself, with Form N-400, is explained in the guide to US citizenship and Form N-400.

Becoming German as an American

For Americans living in Germany, the route has been much shorter since 2024: five years instead of the previous eight. Under Section 10 StAG you can naturalise after five years of lawful habitual residence in Germany. You don't have to give up your American passport for it: the law only requires that your identity and nationality are clarified.

If you're married to a German, Section 9 StAG applies: as a rule, three years of lawful residence in Germany are enough, provided the marriage has lasted two years. Minor children can be naturalised along with you. For American and German couples living in Germany in particular, this is the fastest route to two passports in one family.

German and US dual citizenship: pros and cons

Two passports from two of the most important countries in the world bring freedom and duties. For most people the balance is clearly positive, as long as they meet their obligations properly from the start.

The most important benefit isn't in any table: a passport is a right, not a permission. A Green Card is a residence permit, and a state can attach conditions to permits. Citizenship, by contrast, gives you the right to come back at any time. A German living in the US who naturalises swaps a permission for a right, and keeps the German passport in the process.

The biggest drawback is American tax liability. It's no reason to turn down the US passport, but it is a reason to have it under control from the very start. A detailed weighing-up from the US practice side is in the US Kanzlei's article on the pros and cons of German and US dual citizenship (in German).

Taxes: what a US passport means for your money

Germany taxes you based on where you live; the US taxes its citizens based on citizenship. The IRS says so explicitly: US citizens living abroad are taxable in the US on their worldwide income from all sources, and in principle the same filing and estimated tax rules apply to them as at home.

For German Americans living in Germany, that mainly means:

• US tax return: if you exceed the income thresholds, you file a US return every year. If you live abroad on the regular deadline of 15 April, you get an automatic two-month extension to 15 June, but interest on unpaid tax runs from 15 April.
• FBAR: if your accounts outside the US together hold more than $10,000 at any point in the year, you report them every year by 15 April, with an automatic extension to 15 October.
• No double payment as a rule: income tax you pay in Germany on the same income can be credited against your US tax through the Foreign Tax Credit. The credit reduces your US tax directly.

That's admin, not fate. If you know the deadlines, you hold both passports without penalties and without nasty surprises. The forms, allowances and the double taxation treaty are explained in the guide to US taxes for dual citizens. What applies to children with an American passport is covered in A US passport for your child: what parents should know about US tax, and why your passport doesn't decide your German tax liability is shown in the overview on taxes.

Travelling with two passports: which passport at which border

With two passports there's a simple rule: at every border you show the passport of the country you're entering or leaving, if you're a citizen of it.

• USA: under 8 U.S.C. 1185(b), US citizens may not leave or enter the United States without a valid US passport. An ESTA on your German passport is therefore no longer an option for you. If your US passport has expired, get a new one before you travel.
• Germany: when leaving and entering, you identify yourself as a German, that is, with your German passport.
• Third countries: here you pick the passport that gets you the better terms, and you use the same passport to enter and leave the same country.

How to organise bookings, visas and border checks with two passports is described in Travelling with several passports. If you also hold a third passport and still travel to the US on an ESTA, the rules are in ESTA with a second citizenship.

Military service and Selective Service: what dual citizens need to know

When it comes to the military, too, you're dealing with two legal systems.

On the American side, according to the Selective Service System, almost all male US citizens between 18 and 25 must register. In its overview, Selective Service explicitly lists dual nationals with US citizenship as required to register.

On the German side, Section 28 StAG is what counts. A German who voluntarily signs up with the armed forces of another state whose nationality they hold, without the consent of the Federal Ministry of Defence, loses German citizenship. Minors are exempt, as are cases where an international treaty permits joining, and the loss never occurs if it would leave you stateless. If you're a German American planning a career in the US armed forces, sort out the consent first. What German conscription means for time spent abroad is covered in Conscription and a second passport.

Giving up American citizenship: when you only want one passport

After some years, some German Americans do decide on just one of the two passports, often because of US tax liability. The formal route under 8 U.S.C. 1481(a)(5) is a renunciation before an American diplomatic or consular officer abroad. Here too, voluntariness and intent are prerequisites.

Before you take this step, check two things. First, the tax side: your US tax obligations for recent years should be fully met, and depending on your assets and income, an Exit Tax may apply. Second, whether you might want to keep the US passport after all, because it keeps doors open for you and your children that are hard to open a second time. The process at the consulate, the fee and Form 8854 are explained in the guide to renouncing US citizenship.

The reverse applies to the German passport: renunciation under Section 26 StAG is only possible if you hold more than one nationality, it needs approval, and it only takes effect with the certificate. What you should know beforehand is in Giving up your nationality.

When the US passport is still years away

For most Germans, the American passport is a goal at the end of a long road: first a visa, then the Green Card, then at least three to five years of residence. It's exactly during this time that many lack a Plan B. Naturalisation and citizenship by investment don't rule each other out. Naturalising in the US is the cheaper route and, in the end, the better one, but it takes years and requires you to actually live there. An investment programme buys you that time: a second passport in months while you work towards the third.

Why both routes belong together is shown in CBI and naturalisation. Which programmes exist and how they differ in cost, timeline and family options can be found under Programmes, in the comparison and on the family page. If you're wondering whether the US passport can be reached faster, the realistic routes are in Buying a US passport? Gold Card, EB-5 and the realistic route.

Frequently asked questions