Because of numerical and per-country limits (detailed below), some individuals must wait a significant period of time to apply for “adjustment of status” or an immigrant visa even after the petition is approved by USCIS.
“The Department of State issues a monthly visa bulletin, summarizing the availability of visa numbers for each preference category on a per-country basis. While some visas are “current,” allowing the individual to immediately apply for permanent residence, other categories are considerably backlogged, requiring the applicant to wait years.”
The overall numerical limit for permanent employment-based immigrants is 140,000 per year. This number includes the immigrants plus their eligible spouses and minor children, meaning the actual number of employment-based immigrants is less than 140,000 each year. In addition, each country is limited to 7 percentof the worldwide level of U.S. immigrant admissions, otherwise known as per-country limits.