Many children born outside the United States to U.S. citizens automatically become U.S. citizens at birth. However, there are exceptions.
The status of the child depends on:
- whether both parents, or only one parent, is a U.S. citizen
- when the child was born.
Normally, a parent must be a U.S. citizen at the time of birth, in order to confer automatic citizenship.
There are special rules if parents are unmarried, and a consultation with an immigration attorney may be required.
There are some special options for non-USC children to acquire citizenship before age 18.
It is important to note that unlike in countries such as Canada or Britain, there is no special preference for U.S. citizens born in the United States, in terms of transmitting citizenship. The residence and physical presence requirements apply to all USC parents, no matter where they were born or how they acquired U.S. citizenship.
 Automatic U.S. citizenship at birth
 Both parents U.S. citizens
- If both parents are U.S. citizens (at the time the child is born) then the child is automatically a U.S. citizen provided that at least one parent has, at some stage in that parent's life, "resided" in the United States.
- This law has been in place since at least May 24, 1934 (and possibly sooner)
 One parent a U.S. citizen
 Child born on or after November 14, 1986
- Child will be a USC if the American parent spent a total of 5 years physically present in the United States before the child was born
- At least 2 of the 5 years must have been after the age of 14.
 Child born before November 14, 1986
- From December 24, 1952 the rule is smilar to the above, except that the American parent must have had 10 years physically in the United States (including 5 years after age 14)
- Prior to December 14, 1952 the rules are significantly more complex and there were requirements for the child to live in the United States. Citizenship acquired and then lost can in some cases be recovered.
 Unmarried parents
- If the mother is the U.S. citizen, then mother should have spent a 1 year continuous period in the U.S. or its possessions sometime before the child was born;
 Proof of citizenship
- If one is aged 18 or more when making a citizenship claim, an Adult Citizenship Determination is used instead of a Consular Report of Birth Abroad. Plus a U.S. passport.
- There is also the option to apply to the U.S. Citizenship & Immigration Services on a form N-600 for a certificate proving United States citizenship. This is not necessary for those who have a Consular Report of Birth Abroad but may be advisable for those who do not.
 I am a U.S. citizen but my child is not
There are two options open to you to get citizenship for the child. Otherwise the child will need to qualify for citizenship on his or her own merits (although you may be able to sponsor for an immigrant visa).
 Expedited naturalization based on U.S. grandparent
- If the child has an American grandparent who spent 5 years in the U.S., including 2 years after the age of 14, you may apply to the USCIS for the child to be naturalized as a U.S. citizen. For details, see the section entitled Expeditious Naturalization Through A Grandparent on this page: 
- Application form, instructions for filling it out, and application for request of E-notification (to let you know via e-mail or text) that the application has been received for processing are here:
- The child must visit the United States (tourist visa or visa waiver scheme is ok) for an interview, along with the parent applicant, to complete the naturalization process. On the application form, you may select the USCIS office you where you wish this interview to occur.
- The process must be completed before the child turns 18. Since the processing can easily take 6 months or more, it's safest to apply well before the child's 18th birthday.
 Automatic citizenship upon entering the United States as an immigrant
- If, before the child is 18, the child enters the United States as an immigrant visa holder (or adjusts status to permanent resident while in the U.S.) then the child immediately becomes a U.S. citizen.
- You need to get a citizenship certificate from USCIS (N-600) and obtain a U.S. passport to prove citizenship. A passport is not enough to prove citizenship.
- Technically, the child can leave the United States immediately after obtaining citizenship, however as part of the sponsorship process, the U.S. parent must show an intent to move to the United States. There is also some evidence that USCIS are not accepting such children as US citizens, despite them holding US passports. That is why the N-600 process is essential.
 Obligations of USC children
- Always enter and leave the United States on a U.S. passport
- Not perform any "potentially expatriating acts" with an intention to lose U.S. citizenship
 Natural born citizen
- If the child is automatically a U.S. citizen at birth then child is a natural born citizen and hence constitutionally eligible for the office of President.
- If the child acquires citizenship sometime after birth, then this does not apply.
 Dual citizenship