As a United States Citizen, you can file petitions for your parents, spouse, children and siblings (brothers, sisters). Spouses, parents and children under the age of 18 are considered immediate relatives and could obtain their permanent residence in a relatively short time. Visas for sons and daughters (children over the age of 18) and siblings are subject to availability and may take years. Despite the fact that the visas may take years, we recommend that people file them as it may be the only option available and because time passes and soon enough the visa will be available, but only if a petition is filed.