The marriage must also be bona fide, or real. A marriage entered into solely for immigration purposes is "marriage fraud." Marriage fraud will cause an alien to be permanently barred from coming to the United States. A U.S. citizen who commits marriage fraud may also face criminal charges.

Child

To be a "child" under U.S. law, the person must be under 21 years old and unmarried. A person who is divorced or widowed at the time of the filing of the petition is considered "unmarried." A child can include an adopted child. However, there are special rules surrounding adopted children. A stepchild can qualify as a child if the U.S. citizen married the parent before the child reached the age of 18.

Special issues surround a child born out of wedlock. Generally, if a child is born out of wedlock, and the U.S. citizen is the mother, proving the parent-child relationship is less problematic. But, if the U.S. citizen is the father, the father must show that he has a bona fide relationship with the child before the child reaches the age of 21. The father must be able to show that he provided support for the child, and played a role in the child’s instruction and welfare.

Parent

To petition for a parent, the U.S. citizen must be at least 21 years. The U.S. citizen can petition for step-parents, if the relationship began before the U.S. citizen reached the age of 18. A parent can also include an adoptive parent, provided the adoption occurred before the U.S. citizen reached the age of 16, and the U.S. citizen lived with the adoptive parent for at least two years. An adopted U.S. citizen cannot petition for a natural parent who gave up parental rights.