The Immigration and Nationality Act (INA) sets the number of immigrant visas that may be issued to individuals seeking permanent resident status (a green card) each year.

Immigrant visas available to “immediate relatives” of U.S. citizens are unlimited, so are always available. Immediate relatives include parents of a U.S. citizen, spouses of a U.S. citizen and unmarried children under the age of 21 of a U.S. citizen.

Immigrant visa numbers for individuals in a “preference category” are limited, so are not always available.

The U.S. Department of State is the agency that distributes visa numbers. Family-sponsored preference categories are limited to 226,000 per year and employment-based preference visa are limited to 140,000 per year. In addition, there are limits to the percentage of visas that can be allotted to each country.

Because the demand for some categories is higher than the supply of visas for a given year, a visa queue (waiting list) forms. To distribute the visas among all preference categories, the Department of State gives out the visas by providing visa numbers according to the preference category and one’s priority date. The priority date (explained below) is used to determine an individual’s place in line in the visa queue. When the priority date becomes current, the individual will be eligible to apply for an immigrant visa.

Your priority date can be found on Form I-797, Notice of Action, for the petition filed for you. The length of time you must wait in line before receiving an immigrant visa or adjusting status depends on:

• The demand for and supply of immigrant visa numbers
• The per country visa limitations
• The number of visas allocated for your particular preference category
• Priority Dates for Family Sponsored Preference Cases

For family sponsored immigration, the priority date is the date that the petition is properly filed with U.S. Citizenship and Immigration Services (USCIS).

Priority Dates for Employment-Based Preference Cases

The priority date for an immigrant petition that is based on employment is either:

• The date the petition was properly filed with USCIS, or
• The date the labor certification application was accepted for processing by the Department of Labor (when a labor certification is required)
• Pending Employment-Based Form I-485 Inventory

A visa must be available before a person can obtain an employment-based green card. Currently, about 234,000 people have applied for employment-based adjustment of status (green card) in the United States and are waiting for a visa. Because more people want a green card than there are visas available, not everyone who wants a green card can get one immediately. How long you wait for a visa depends on your priority date, preference category, and the country your visa will be charged to (usually your country of birth).

U.S. Department of State Visa Bulletin

The U.S. Department of State publishes a monthly report of visa availability referred to as the “Visa Bulletin.” The monthly Visa Bulletin serves as a guide for issuing visas at U.S. consulates and embassies. USCIS also uses this guide to determine whether a Form I-485, Application to Register Permanent Residence or Adjust Status, may be accepted or adjudicated. A visa must be available both at the time a person files Form I-485 and at the time of the final decision on the application.

Check Your Place in the Visa Queue

The Visa Bulletin allows individuals to check their place in the immigrant visa queue. The Visa Bulletin provides the cut-off dates for the different categories and countries for family, employment and diversity visas.

When Visa Numbers Are Available

If demand is less than supply in a given preference visa category and country of birth (“or country of visa chargeability”), then immigrant visas are current. Visas are available when the chart designation is “C” for current.

This means that immigrant visa numbers are available for all qualified overseas applicants and adjustment applicants in that particular visa preference category and country of birth.

When Visa Numbers Are Not Available

If the demand is more than supply for a particular visa category or foreign state and cannot be satisfied within the allowable limits, the Visa Office considers the preference visa category or foreign state “oversubscribed” and must impose a cut-off date.

In this instance, only overseas and adjustment applicants who have a priority date earlier than the date listed in the Visa Bulletin may be given an immigrant visa number. A visa is available to an individual, therefore, if his/her priority date is earlier than the date listed for that visa category and country. Visas are unavailable when the chart designation is “U” for unavailable.

For example, if a date of 15Sept02 is shown for individuals from China in the Family 1st preference category in the Visa Bulletin, visas are currently available for individuals with a priority date earlier than September 15, 2002.

Visa Retrogression

Sometimes, a priority date that is current one month will not be current the next month. This is called visa retrogression, which occurs when more people apply for a visa in a particular category than there are visas available for that month. Visa retrogression most often occurs when the annual limit has been reached. When the new fiscal year begins on October 1, a new supply of visa numbers is available and usually, but not always, brings back the dates to where they were before retrogression.

Cross-Chargeability

Employment based cases are amenable to visa cross-chargeability provisions for principal applicants (that may have a visa retrogressed priority date), who have spouses from a country for which a visa cut-off date may provide a visa allocation. For more information on cross-chargeability, see the “Department of State: Visa Homepage“.

Source: http://www.uscis.gov