The F1 and F3 Green Cards are family based, first and third preference visas that provide lawful permanent residence to adult and married children of US citizens. There is a limit to the number of visas available in these categories each year, so there is usually a waiting period before an immigrant visa number becomes available.
Immediate family members, such as spouses, parents and unmarried children under 21 years of age, of US citizens may be eligible for an IR Green Card which is unlimited and no waiting period applies.
To qualify for an F1 Green Card, the applicant must be the child of a US Citizen, be unmarried and be at least 21 years of age.
To qualify for an F3 Green Card, the applicant must be the child of a US Citizen and married.
US Green Card applicants will also need to meet health and character requirements.
The F1 and F3 Green Cards entitle adult and married (any age) children of US citizens to reunite with their family and become lawful permanent residents in the US. In addition, an F1 Green Card holder's unmarried children (under the age of 21) and an F3 Green Card holder's spouse and unmarried children (under the age of 21) may be entitled to accompany or join them in the US permanently.
US permanent residents are entitled to attend any public or private school in the US, work in the US without a visa or employment authorization document, travel outside the US with few limitations, sponsor close relatives for US permanent residence and apply for US citizenship when eligible to do so.