If you are a U.S. citizen seeking permanent residency for your brother or sister, and you have the same father but different mothers, you must file the following items with the U.S. Citizenship and Immigration Services:
Note: If anyone’s name has been legally changed (if it differs from the name on his or her birth certificate), evidence of the name change must be submitted.
Note: If either you or your sibling were born out of wedlock (your birth parents were not married when you were born), you must provide evidence that you took the actions necessary to satisfy the legitimation law of the birth country of the person born out of wedlock while the individual was under 18 years of age and unmarried. Legitimation laws require fathers to legally acknowledge their children.