US Citizenship by Descent: Children of US Citizens Born Abroad

Whether a child born abroad is a US citizen at birth depends on the parents' citizenship, whether they were married, and the parent's time in the US before the birth. The rules below apply to children born on or after November 14, 1986. Earlier births follow older, stricter rules.

"Physical presence" means actual days spent in the US, not just holding citizenship. School records, transcripts, tax records, and old passports help prove it. Time abroad as a US government employee or in the US military (and as their dependent) can count in some cases.

If the citizen parent never lived in the US long enough, the child may not be a citizen at birth even though the parent is. The child may still qualify later through the routes below.

If your child was born abroad and is a citizen at birth, apply at the US embassy or consulate for:

• A Consular Report of Birth Abroad (CRBA), Form FS-240, applied for on Form DS-2029. It is proof of citizenship, like a birth certificate for a child born in the US.
• A US passport, often at the same appointment.

Apply before the child turns 18 for a CRBA. Bring the child's foreign birth certificate, the parents' marriage certificate if married, proof of the parent's US citizenship, and proof of physical presence. Some embassies ask for DNA testing when the documents are not enough. Current fees are on the State Department website.

Adults who were citizens at birth but never documented it can apply directly for a US passport or file Form N-600.

People in the US who became citizens through a parent, at birth or later, can ask USCIS for a Certificate of Citizenship on Form N-600. It is optional; a US passport also proves citizenship. As of September 2026 the fee is $1,385 on paper or $1,335 online, with no fee for some military members and certain adopted children.

Under the Child Citizenship Act of 2000 (INA section 320), a child automatically becomes a US citizen when all of these are true before the child turns 18:

• At least one parent is a US citizen (by birth or naturalization)
• The child is a lawful permanent resident (green card holder)
• The child lives in the US in the legal and physical custody of the citizen parent

No application is needed to become a citizen, but you will want proof: a US passport or an N-600 certificate. Adopted children who meet the adoption rules qualify too.

If a child lives outside the US and was not a citizen at birth, a US citizen parent can apply on Form N-600K (same fee as the N-600). Requirements include:

• The child is under 18 and lives abroad in the legal and physical custody of the citizen parent
• The citizen parent was physically present in the US for 5 years, at least 2 after age 14, or the child's US citizen grandparent meets that requirement
• The child is temporarily present in the US on a lawful admission, such as a visitor visa, for the interview and oath, which must happen before age 18

This is the only common way a grandparent's time in the US helps. The US does not give citizenship directly through a grandparent.

• Not enough physical presence. A parent who grew up abroad may not have the required years. The child may need a green card first, then qualify under INA 320.
• Missed age 18. Most routes end at 18. Adults who did not qualify usually need to immigrate and later naturalize.
• Unmarried parents and assisted reproduction. These cases have special rules. Ask the embassy or a licensed immigration lawyer.
• Dual citizenship. A child can be a US citizen and a citizen of another country. See dual citizenship. Remember that US citizens, including children, must use a US passport to enter and leave the US.

Canada and Mexico have their own rules; see Canadian citizenship by descent and Mexican citizenship by descent.