1. For immigration purposes, "child" means unmarried son/daughter who is under 21 and who is one of the following:
A. Child born in wedlock;
B. Stepchild, whether born out of wedlock or not, if the stepchild was under 18 when the marriage creating the stepchild status occurred (it is not required that the petitioning parent and the stepchild live(d) together);
C. Child legitimated under the law of the child’s or the father’s residence/domicile, if at the time of legitimation, the child was under 18 and was in legal custody of the legitimating parent(s);
D. Child born out of wedlock, if immigration status is sought by/through the child by virtue of the child’s relationship to its natural mother/father (in case of natural father, the father must have had bona-fide parent-child relationship with the child); or
E. Adopted child, if the child was under 16 when adoption was finalized, and has been in legal custody of, and has resided with, the adopting parent(s) for at least 2 yrs.
2. Generally, an adopted child’s natural parent cannot receive any immigration benefits based on such parentage. The only exception is where all of the following are met, which is very rare:
A. The adopted child has not received any immigration benefits based on the adoptive relationship;
B. Natural parent-child relationship satisfying #1 above once existed between the adopted child and the natural parent
C. The adoption has been lawfully terminated under applicable law; and
D. The natural parent-child relationship has been re-established by law.
3. In order to qualify as a “son/daughter” in preferences F1, F2, or F3, the "son/daughter" must have been a “child” as described in #1 above.
4. Under immigration law, in order to qualify as a “parent” of a person, the person must be, or must have been, a “child” as described in #1 above.
5. In order for the "parent" to qualify as an immediate relative of a U.S. citizen son/daughter, the U.S. citizen son/daughter must be 21 or older.
6. In order to qualify as “siblings”, they must be, or must have been, “children” (as described in #1 above) of a common parent. But it is not required that they are/were “children” simultaneously.
7. In order to qualify as "spouse", you must have a valid marriage, meaning:
A. The marriage must be a marital union that is legally valid in the state or country where the marriage was entered into. Therefore, the marriage must be properly registered with a proper civil authority; having a ceremony/party by itself is usually not sufficient.
B. The marital relationship must be a bona-fide and good-faith relationship between you and your spouse; the marriage must not have been entered into for the purpose of obtaining immigration benefits.
8. Pursuant to the U.S. Supreme Court's decision in June 2013 striking down part of the Defense Of Marriage Act (DOMA) as unconstitutional, same-sex marriages are now fully recognized under immigration law, as long as they meet the requirements described in #7 above.
9. In case of a U.S. citizen's spouse who, at the time of the U.S. citizen’s death, has been the U.S. citizen’s spouse for at least 2 yrs and was not legally separated, the spouse and each of his/her children remain "immediate relatives" after the U.S. citizen’s death, but only if the spouse files a petition within 2 years after the U.S. citizen’s death and only until the spouse re-marries.