The Visa Bulletin is a monthly report published by the Department of State that indicates how many immigrant visas are available and when they will be ready for processing. This is called the visa availability and priority date.
The bulletin serves to find out how long it takes to process an immigrant visa, depending on the country of origin. It is also a guide to issuing visas at U.S. consulates and embassies.
Immigrants who submit an application and are waiting for their turn for an immigrant visa can see when their priority date will be processed in the Visa Bulletin.
Priority dates in the Visa Bulletin are ordered according to a preference system governing immigrant visa categories.
The cut-off date indicates the time after which visas will no longer be available for each of the categories.
The Visa Bulletin does not apply to visa applications of immediate relatives of U.S. citizens - that is, parents, spouses and unmarried children under the age of 21. These individuals have immediate access to an immigrant visa as long as they meet all the requirements.
HOW TO READ THE BULLETINÍN OF VISAS:
Here you can see the May 2015 Visa Bulletin:
If you look at the Mexico column, this Visa Bulletin indicates that in the month of May 2015, petitions in the F1 family category, which were filed before November 8, 1994, are being processed. That means that there is approximately a 21-year wait for unmarried children of U.S. citizens who are Mexican nationals, over the age of 21.
But in the case of the F2A family category, which is for spouses or unmarried children under the age of 21 of U.S. permanent residents, applications submitted before August 8, 2013 are being processed. The wait for an available visa is approximately 2 years.
U.S. immigration laws limit how many immigrants can enter and live in the country each year. Therefore, only a limited number of visas are allowed to be issued.
The limit also depends on the applicant's country of origin. By law, a single country cannot receive more than 7% of the total number of visas issued in a fiscal year. This restriction is to be more equitable, and to prevent any one country from taking the majority of available visas.
For example, because there is a lot of demand from Mexico, the visas available for immigrants from that country run out. That is why the wait is longer for Mexican immigrants.
Priority dates may change from month to month. Generally, they move forward, but sometimes they can be delayed, causing a priority date that is current one month not to be current the next month.
When that happens, the Visa Bulletin has to be adjusted. The process is called visa retrogression and happens when there is too much demand and not enough visas for a particular country. This means that the person will have to wait even longer for a visa to become available.
Monthly updates of the dates are made based on the different categories, the countries of origin of the immigrants, the number of visas that have been issued so far and an estimate of the demand for visas.