Embassy of the United States Baghdad, Iraq

The priority date essentially decides a person's turn to apply for an immigrant visa. 

Congress places an annual limit on the number of visas available in several categories.  These cases are prioritized according to the date on which the petition was approved by the U.S. Citizenship and Immigration Service, with the oldest cases receiving priority.  

Cases with a priority date which is not current, are held at the National Visa Center (NVC).  Once their priority date becomes current, the NVC will schedule their appointment and forward the case file to the U.S. Embassy or Consulate having jurisdiction over the applicant's place of residence.

Priority DatesCurrent/non-current

The numerical limits on the number of immigrant visas that can be granted to aliens are based on place of birth, not citizenship. Because of the numerical limits, this means there is a waiting time before the immigrant visa can be granted. The terms current/non-current refer to the priority date of a petition in preference immigrant visa cases in relationship to the immigrant cut-off date. If your priority date is before than the cut-off date according to the monthly Visa Bulletin, your case is current. This means your immigrant visa case can now be processed. However, if your priority date is later/comes after the cut-off date, you will need to wait longer, until your priority date is reached (becomes current). To find out whether a preference case is current, see the Visa Bulletin or by calling the following U.S. telephone number: +1 (202) 663-1541.

Immediate relative immigrant visa cases do not have country numerical limits, with waiting times as a result of the country limits. The terms priority date, cut-off date and current/non-current does not apply for immediate relative cases.