The H-1B visa is meant to fill job gaps in special occupations where there are not enough domestic workers to meet demand. The employer must petition US Citizenship and Immigration Services (USCIS) to hire a foreign national, and must demonstrate that there are no qualified workers already in the US. After the potential employee files an application for an H-1B visa, USCIS examines his or her educational and work background to confirm that he or she meets the requirements for an H-1B visa.
Because these visas are in high demand, it's advisable to petition USCIS as soon as possible. For employees who wish to begin working on or after October 1st, you should submit your petition on or by April 1st. H-1B employees may work for more than one US employer, but each employer must file a petition with USCIS.
H-1B holders are allowed to live in the United States as long as they are employed with the sponsor company, and their spouse and children may accompany them under an H-4 visa. Holders of an H-1B visa are also eligible to apply for permanent residence in the United States.