One way that a foreign national is eligible to become a lawful permanent resident of the United States is by being sponsored by a relative. The relative must be able to prove that he or she is a citizen of the United States and must demonstrate that he or she can support the foreign national at 125% above the mandated poverty line. In addition, if the relative is a U.S. citizen, then he or she may sponsor a husband or wife, unmarried children under 21, married son or daughter of any age, brother or sister (if the sponsor is at least 21), or parent (if the sponsor is at least 21).