If your relative is an immediate relative, i.e. U.S Citizen’s spouse, unmarried children under 21 years of age and parents, special consideration is given to individuals in this category.
For individuals in a “preference category”, the high demand for and supply of visa numbers, the per country visa limitations and the number of visas allocated for a particular preference category means your relative may have to wait several years in line before being allowed to immigrate to the United States.
The U.S. Department of State is responsible for distributing visa numbers. Family sponsored categories are limited to a minimum of 226,000 per year. There are also limits to the percentage of visas that can be allotted to each country.
Because the demand for visas is generally higher than the supply of visas in any given year, a waiting list forms. In this instance visas are distributed based on the preference category and the priority date (date of filing). The priority date is used to determine an individual’s place in line. When the assigned priority date becomes current the individual will be eligible to apply for an immigrant visa