Citizenship When One Parent is US Citizen

Navigating the path to US citizenship can be confusing, especially when families have mixed immigration statuses. A very common question we hear is: “Can I (or my child) get citizenship when one parent is US citizen?”

The short answer is often yes, but the “how” and “when” depend entirely on the child’s age, residency, and green card status. US immigration law distinguishes between children who are born citizens and those who become citizens after birth through their parents.

This guide breaks down the Child Citizenship Act of 2000, the difference between automatic citizenship and naturalization, and which forms you need to file to secure your family’s future.

Understanding the Child Citizenship Act of 2000 (CCA)

The most important law regarding citizenship when one parent is US citizen is the Child Citizenship Act (CCA) of 2000. This law simplified the process significantly.

Before this law, the process for children to derive citizenship was much harder. Now, under Section 320 of the Immigration and Nationality Act (INA), a child born outside of the United States automatically becomes a US citizen when all of the following conditions are met:

1. Parentage: At least one parent, including an adoptive parent, is a US citizen by birth or through naturalization.
2. Age: The child is under the age of 18.
3. Residency: The child is residing in the United States in the legal and physical custody of the US citizen parent.
4. Status: The child is a Lawful Permanent Resident (has a Green Card).

If your child meets these criteria, they might already be a US citizen without you realizing it. You do not technically “apply” for their citizenship; you apply for the proof of it.

Why Proof Matters

Even if the law says your child is a citizen, they need a document to prove it to get a passport, vote later in life, or apply for federal jobs. This is where Form N-600 comes in.

Scenario 1: The Child is Under 18 and Lives in the US

This is the most common scenario for families we help at Greenbroad. Perhaps one parent was born in the US, or one parent recently passed their naturalization test.

If the child is under 18 and has a Green Card, they likely derived citizenship the moment the parent became a citizen (or the moment the child entered the US with a Green Card if the parent was already a citizen).

The Process: Form N-600

To get the official Certificate of Citizenship, you file Form N-600.

• Who Files: The US citizen parent files on behalf of the child.
• Evidence Needed: You must prove the relationship, the child’s age, the child’s Green Card status, and the parent’s citizenship.
• Cost: The filing fee for N-600 is significantly higher than other forms (over $1,000 in many cases), but it is a one-time fee.
• Interview: An interview is sometimes required, but not always.

Scenario 2: The Child is Over 18

This is where things get tricky. If you are reading this and you are already over 18, or your child has already turned 18, the automatic rules of the CCA generally do not apply to you.

You cannot “derive” citizenship from a parent if you were over 18 when the parent naturalized.

The Process: Form N-400

If you are over 18, you must apply for naturalization on your own merit. This involves filing Form N-400.

To qualify, you must:

1. Be at least 18 years old.
2. Have held a Green Card for at least 5 years (or 3 years if you are married to a US citizen).
3. Demonstrate continuous residence and physical presence in the US.
4. Pass the English and Civics tests.
5. Demonstrate good moral character.

Even if your parent is a US citizen, if you are an adult, you follow the standard path for Green Card holders.

Scenario 3: Child Born Abroad (Acquisition at Birth)

Sometimes, a child is born abroad to a US citizen parent and acquires citizenship at birth. This is different from “deriving” it later.

If a child is born overseas:

• Two Citizen Parents: If both parents are US citizens and at least one lived in the US prior to the birth, the child is likely a citizen.
• One Citizen Parent: If one parent is a US citizen and the other is not, the US citizen parent must have been physically present in the US for a specific period (usually 5 years, with at least 2 being after age 14) before the birth.

If the child acquired citizenship at birth, you generally apply for a Consular Report of Birth Abroad (CRBA) at the nearest US embassy shortly after the baby is born.

Scenario 4: Child Residing Abroad (Form N-600K)

What if the child lives outside the US with their US citizen parent? The automatic citizenship rule (Section 320) requires the child to live in the US.

However, Section 322 of the INA allows a US citizen parent to apply for naturalization for a child residing outside the US.

Requirements for N-600K:

1. The child is under 18.
2. The US citizen parent has been physically present in the US for 5 years (2 after age 14).
3. The child is temporarily present in the US legally (e.g., on a tourist visa) for the interview.

This process results in a Certificate of Citizenship. Note that the child must complete the process and take the oath before turning 18.

Step-Parents and Adoptive Parents

Families come in all shapes and sizes, and immigration law has specific rules for them.

Adopted Children

Adopted children are treated the same as biological children under the Child Citizenship Act, provided:

• A full and final adoption was completed.
• The child meets the requirements for an “adopted child” under immigration law (usually adopted before age 16).

Step-Children

This is a critical distinction: Step-children do NOT derive citizenship automatically from a step-parent.

If a US citizen marries a non-citizen with a child:

1. The step-parent can sponsor the child for a Green Card.
2. Once the child has the Green Card, they do not automatically become a citizen through the step-parent.
3. The child typically must wait until they are 18 and file Form N-400 on their own, unless the step-parent legally adopts the child before the child turns 16 (and meets other criteria).

Documentation Checklist

Whether you are filing Form N-600 (Certificate) or Form N-400 (Naturalization), documentation is key.

For Form N-600 (Under 18)

You will need to prove the “3 Golden Rules”:

1. Child’s Status: Child’s Green Card and Birth Certificate.
2. Parent’s Status: Parent’s US Birth Certificate, Naturalization Certificate, or Passport.
3. Relationship & Custody: Marriage certificate of parents, divorce decrees (if applicable), and proof the child lives with the citizen parent (school records, medical records).

For Form N-400 (Over 18)

1. Copy of Green Card (front and back).
2. Marriage certificate (if applying based on marriage).
3. Evidence of trips outside the US.
4. Proof of Selective Service registration (for males).

Costs and Processing Times

Understanding the financial and time commitment is helpful for planning.

Costs

• N-400 (Naturalization): The government filing fee is $760.
• N-600 (Certificate of Citizenship): The fee is generally higher, currently around $1,335 (online filing) or $1,385 (paper filing).
• Greenbroad Service: We prepare either application package for a flat fee of $749.

Timelines

• N-400: processing usually takes 8 to 14 months, depending on your local field office.
• N-600: Processing times vary wildly but often take 6 to 14 months.

Common Mistakes to Avoid

When seeking citizenship when one parent is US citizen, avoid these pitfalls:

1. Assuming it’s automatic for step-children: As mentioned, step-children generally need to naturalize on their own after age 18 unless adopted.
2. Waiting too long (N-600K): If you live abroad, you must complete the N-600K process before the child turns 18. If the application is pending when the child turns 18, it will be denied.
3. Applying for N-400 when you are already a citizen: If you derived citizenship automatically, filing an N-400 is technically incorrect. You should file N-600. However, USCIS may let you withdraw and refile, but you lose time and fees.
4. Lack of Custody Proof: For divorced parents, proving the child was in the “legal and physical custody” of the citizen parent is the most common reason for Requests for Evidence (RFEs).

Frequently Asked Questions

Here are answers to the most common questions about parents and citizenship.

Does a child automatically become a citizen if one parent is a US citizen? Yes, under the Child Citizenship Act of 2000, a child may automatically become a citizen if they are under 18, possess a Green Card, and reside in the US with the citizen parent. If these conditions are met, citizenship is automatic, though filing Form N-600 is recommended to get proof.

Can I apply for citizenship through my parents if I am over 18? If you are already over 18 and your parent naturalizes, you generally cannot derive citizenship automatically from them. Instead, you must apply for naturalization on your own using Form N-400 once you meet the residency requirements as a Green Card holder.

What form do I file for a child of a US citizen? If the child automatically acquired citizenship under the Child Citizenship Act, you file Form N-600 (Application for Certificate of Citizenship). If the child resides abroad and is applying under Section 322, you would file Form N-600K.

Does the child need to live in the US to get citizenship? Usually, yes. To derive citizenship automatically after birth, the child generally needs to be living in the United States in the legal and physical custody of the US citizen parent while holding lawful permanent resident status.

What is the Child Citizenship Act of 2000? This is a law that allows certain foreign-born children of US citizens to acquire citizenship automatically. It applies to children who are under 18, have at least one US citizen parent, and live in the US as lawful permanent residents.

Conclusion

Securing citizenship when one parent is US citizen is a powerful benefit of the US immigration system. It protects your child from deportation and grants them all the rights of being American.

If your child is under 18 and lives with you in the US, they may already be a citizen. If they are over 18, they can follow in your footsteps by filing for naturalization.

At Greenbroad, we specialize in helping families navigate this paperwork. We are not a law firm, but our expert document preparation service ensures your forms are error-free and ready for USCIS.

Related Articles:

• N-400 Filing Fee 2026 - Cost Breakdown
• Citizenship Processing Time 2026: How Long Does Naturalization Take?
• Citizenship Interview Questions - What They Ask

Disclaimer: Greenbroad is not a law firm and does not provide legal advice. We are a document preparation service. Fees and processing times mentioned are subject to change by the government.

External Resources:

• USCIS: I am the Child of a US Citizen