Certificate of Citizenship · Form N-600
Many children of U.S. citizens are already citizens. The N-600 proves it.
We help families and adults work out whether citizenship passed from a parent, which law applies, and how to prove the custody, residence, and relationship facts that USCIS asks about.
Citizenship gained this way is automatic. No application is needed to become a citizen, but without a certificate or passport the fact can be missed for years, sometimes until a job, a benefit, or a court case depends on it.
How citizenship passes
The family's history decides which law applies.
Form N-600 documents citizenship a person already has. The work is showing which rule gave it to them, and when.
Child Citizenship Act (INA § 320)
A child born abroad becomes a citizen automatically once all of these are true at the same time before age 18: one parent is a U.S. citizen, the child is a green card holder, and the child lives in the United States in that parent's legal and physical custody.
Born abroad to a U.S. citizen parent
Some children are citizens from birth under INA §§ 301 and 309, depending on the parents' marriage and the citizen parent's time in the United States. The N-600 can document it for a person living here.
Children born abroad (CRBA)Turned 18 before February 27, 2001
The Child Citizenship Act does not apply. Former INA § 321 generally required the naturalization of both parents, or of the surviving parent, or of the parent with legal custody after a legal separation, all before 18.
Adopted children
An adoptive U.S. citizen parent counts, if the adoption meets the immigration-law definition of an adopted child. Some adopted children receive a certificate from USCIS without filing.
Military and government families
Since March 26, 2020, a child living abroad with a citizen parent stationed overseas in the armed forces or government service can acquire citizenship under INA § 320, if the other requirements are met.
Children outside the United States
A child under 18 who lives abroad with a citizen parent uses a different application, Form N-600K under INA § 322, which ends with a visit to the United States for the interview and oath.
The law in force when the last requirement was met controls. Birth dates, the parent's naturalization date, and any divorce or custody order all go on the timeline before anything is filed.
Legal and physical custody
Most N-600 cases turn on who the child lived with, and under what authority.
Under INA § 320, the child must live in the United States in the citizen parent's legal and physical custody before turning 18. USCIS presumes some of these facts and asks for proof of others.
How USCIS reads it
- Married parents living together are presumed to share custody, even if the child was born before the marriage
- A surviving parent is presumed to have custody if the other parent has died
- If the parents never married, the parent the child lives with has custody; a citizen father must also have legitimated the child
- After a divorce or legal separation, the most recent court order controls; joint custody counts
- Private agreements between parents generally do not count, and custody orders entered after 18 that change the past are not recognized
Proof the child lived with the citizen parent
- School records showing the same home address
- Medical, hospital, or vaccination records with that address
- The citizen parent's tax transcripts listing the child as a dependent
- Sworn statements from either parent giving the dates the child lived with the citizen parent
- All of it from the years before the child turned 18
A person born abroad is presumed not to be a citizen, so the applicant carries the burden of proving each requirement by a preponderance of the evidence.
Why the certificate matters
A citizen without papers still has to prove it.
No one is required to hold a Certificate of Citizenship. It is the proof that makes every later step simpler.
It does not expire
A U.S. passport proves citizenship only while it is valid. Neither a Certificate of Citizenship nor a Consular Report of Birth Abroad expires.
It replaces the green card
A child who derived citizenship is no longer a permanent resident. The green card is surrendered when the certificate is issued, which ends renewals for good.
It answers the question once
Federal jobs, benefits, financial aid, and passport applications ask for proof. A certificate settles it without rebuilding the family history each time.
It can stop a mistaken case
People who derived citizenship without knowing it sometimes apply to naturalize, or face immigration consequences meant for non-citizens. A citizenship review should come first.
Adults
There is no age limit for filing an N-600.
The requirements had to be met before 18, but the application can be filed at any age. Adults file for themselves.
Check before you renew a green card or apply to naturalize. If a parent became a citizen while you were a minor living with them, you may already be a U.S. citizen.
- The evidence is old. School, medical, and tax records from childhood take time to request. We start that early.
- The law may be older too. Adults who turned 18 before February 27, 2001 are judged under former INA § 321, which has different custody and parent rules.
- A criminal record does not undo citizenship. A person who derived citizenship is a citizen. The certificate documents it; it is not a discretionary benefit.
- In removal proceedings? A claim to citizenship can be raised in immigration court. Tell your lawyer at once.
How it works
From the family timeline to the certificate.
The application is filed with USCIS by an adult applicant, or by a citizen parent or legal guardian for a child under 18.
- 01
Build the timeline
Birth, the parents' marriage or divorce, the parent's citizenship date, the child's green card, and where the child lived, year by year until 18.
- 02
Gather the documents
Birth and marriage records, the parent's proof of citizenship, divorce or custody orders, the green card, any adoption decree, name changes, and proof of residence with the parent.
- 03
File Form N-600
The application goes to USCIS with the filing fee. Fees change; see the current amounts on our fee guide.
- 04
Photo and signature
USCIS may schedule the applicant, whatever their age, for a photo and signature appointment. A parent may sign for a child under 14.
- 05
Interview
The applicant, and the citizen parent for a child, usually attend. USCIS may waive the interview when the documents already prove eligibility.
- 06
Oath and certificate
Applicants 14 and older take the Oath of Allegiance; it is waived for younger children. The certificate shows the date citizenship began. A denial can be appealed, and the deadline is short.
Private two-minute guide
Could citizenship already have passed to you or your child?
Answer three general questions. The guide suggests where a review should start; it does not decide citizenship or send your answers to the firm.
Official sources
Where the rules are published.
The requirements come from the statute and USCIS policy. Check the current form edition and filing instructions before you file.
Questions
What families ask us about the N-600.
Short answers to common questions. The family's dates and documents may change the answer.
My child got a green card and I am a citizen. Is my child a citizen?
Very possibly. Under INA § 320, a child under 18 with a green card who lives in the United States in your legal and physical custody becomes a citizen automatically. The N-600 documents it.
Do we have to file an N-600?
No. The citizenship exists without it. A U.S. passport is another way to prove it, but a passport expires and a certificate does not.
Is it too late if I am already an adult?
No. The requirements had to be met before 18, but the N-600 can be filed at any age. Adults file for themselves.
What if my parents divorced?
The citizen parent needs legal custody, usually shown by the most recent court order, and the child must have lived with that parent. Joint custody counts. Private agreements generally do not.
My parents were never married. Does that matter?
It can. USCIS presumes custody with the parent the child lived with, but a citizen father must also have legitimated the child under the law of the child's or father's residence.
I turned 18 before 2001. Which law applies?
If you turned 18 before February 27, 2001, the Child Citizenship Act does not apply. Former INA § 321 generally required both parents to naturalize, or the surviving or custodial parent in certain cases, before you turned 18.
Will there be an interview?
Usually, and the citizen parent attends for a child. USCIS may waive it when the documents already in its records, or filed with the application, prove eligibility.
Our child lives abroad. Can we file the N-600?
Usually the N-600K is the right form for a child under 18 living abroad. USCIS accepts an N-600 from someone outside the country but decides it only once the person is in the United States. A CRBA may also fit if the child was a citizen at birth.
How much does it cost and how long does it take?
USCIS sets the filing fee and changes it from time to time; see our fee guide. Processing times vary by office. We quote our legal fee in writing after reviewing the family's documents.
N-600 help at a glance
- Who it is for
- People in the United States who became citizens through a U.S. citizen parent, at birth or after.
- Form
- USCIS Form N-600, Application for Certificate of Citizenship.
- Main rules
- INA § 320 (Child Citizenship Act), former INA § 321, INA §§ 301 and 309, and INA § 341.
- Document issued
- Certificate of Citizenship. It does not expire.
- Other routes
- U.S. passport; Consular Report of Birth Abroad; Form N-600K for children living abroad.
- Languages
- English and Spanish.
- Office
- 609 W. Hamilton Street, No. 102, Allentown, PA 18101 · (484) 763-4984
Information reviewed against official sources, including INA §§ 320 and 341 and the USCIS Policy Manual, volume 12, parts H and K, on October 7, 2026. This page provides general information, not legal advice; it does not decide anyone's citizenship or create an attorney-client relationship. Rules for older cases differ, and fees and procedures change.
Reviewed and updated
Birth · Parent · Custody
Bring the birth certificate, the parent's citizenship proof, and the green card. We will map the rest.
A first review can start with those three documents and any divorce or custody order. We build the timeline from there.
English and Spanish · Allentown · Pennsylvania · New Jersey · New York · Representation where permitted