A foreigner, arriving to perform either skilled or unskilled labor in the USA, is inadmissible, which means he or she shall not be allowed to enter the United State as either immigrant or nonimmigrant or adjust status inside the United States to that of the Legal Permanent Resident, without having been first issued a labor certification by the U.S. Department of Labor (DOL). In it, the DOL must certify in no ambiguous terms that hiring a foreign worker would not take away the job opportunity from the workforce in the United States.  Without such certification an employer would not be allowed hiring a foreign worker to work either temporary or permanently in the United States. This requirement is set forth as inadmissibility grounds in §212(a)(5)(A) of the Immigration and Nationality Act (INA) and applies most employment nonimmigrant visas as well as the second (EB2) and third (EB3) employment based preference categories of immigrants.

The second employment based category (EB2) applies to not exempt foreigners who are seeking to immigrate into the United States if they are either individuals of exceptional abilities in science, art or business or holders of advanced degrees in professional fields. The third employment based category (EB3) applies to foreigners who are seeking to immigrate to the United States on the basis of an offer of employment and includes individuals with higher education – Bachelor Degree holders; skilled or unskilled workers in a variety of fields.

Put simply, in relevant here immigrant visa context, permanent Labor Certification is a process in which the U.S. Department of Labor issues a document certifying that at the time when the certification is issued, it has determined after having analyzed the recruitment efforts of the petitioning employer, marker conditions and other relevant information that

1. there are no qualifying U.S. workers available who would be willing and able to fill the position offered by the employer, or that such workers cannot be found in the area of intended employment at the time of the filing of the application by the employer;
2. employing the foreign national will not adversely affect the wages and working conditions of similarly employed U.S. workers.

This process is very elaborate and highly regulated. Most recent and rather detailed regulations, which implemented the new system of labor certification known as Program Electronic Review Management (PERM), came into effect on March 28, 2005.  This system of recruitment and application review applied to all permanent labor certification applications made by the petitioning employers on behalf of EB2 and EB3 applicants on or after that day. The final version of the PERM regulations was published on December 27, 2004. While it brought mixed results, it did improve dramatically the permanent labor certification process and substantial reduced the backlog. It did so by completely reengineering the entire process including its procedures and ever the forms used. The new system completely abolished the USDOL ETA Form 750 having replaced them with the new ETA Form 9089 applications had to be filed under the new PERM regulation at the appropriate National Processing Center (NPC). The system also abolished the role of the state department of labor and concentrated the entire process with the US DOL instead.

The PERM regulations did not apply retroactively. That meant that all applications filed under the regulation in effect prior to March 28, 2005, continued to be processed under the rule in effect at the time of filing at an appropriate Backlog Elimination Center until such time as the backlog was eliminated.

The implore, however was given an option of affirmatively asking the USDOL to withdraw an application filed under the regulation in effect prior to March 28, 2005, and still in process, and to refile an application for the identical job opportunity under the refile provisions of the PERM regulation When done so, the employer was permitted to use the previously filed ETA Form 750 application filing date.

The day when US DOL received an application for PERM, is referred to as the filing date. If the application is later certified by the US DOL and corresponding I-140 immigrant petition is filed by the employer with the USCIS, that very date represents the priority date for the I-140 application. In other words, it is not the day when the I-140 but PERM was filed that will eventually determine how soon the I-140 will be processed by the DHS. Certified PERM applications must be submitted as part of the corresponding record of the I-140 Immigrant Petition for Alien Worker for processing with the relevant USCIS Service Center. The certification has a validity period of 180-days and expires if not submitted to USCIS within this period. Once the period is over, a new certification would need to be certified before the I-140 could be submitted.