In order to obtain a visa to work in the United States, you must obtain certification from the U.S. Department of Labor and visa authorization from the U.S. Citizenship and Immigration Services (USCIS). Normally, you must have a job offer, and the position must suffer from a lack of qualified U.S. workers.
Types of Visas
The USCIS offers different types of visas for different occupations. The H-1B visa category is for "specialty occupations." Normally these are white-collar positions that require a college degree. The H-2A visa category is for seasonal agricultural workers, while the H-2A is for seasonal non-agricultural workers. The L-1 visa is for intracompany transferees from abroad. The maximum periods of validity for such visas vary according to visa category and are revised from time to time. As of 2011, H-1B visa holders are authorized for three years, extendable to six years. Seasonal workers are normally admitted for a few months, but sometimes up to a year. The L-1 visa is valid for three years, extendable to seven years.
All visa categories except for the L-1 category require certification from the U.S. Department of Labor before the USCIS will process a visa application. The Department of Labor must certify that there is a labor shortage in the field for which the visa is sought, that hiring the employee will not disadvantage U.S. workers and that the employer tried and failed to recruit U.S. workers for the position. After a failed attempt to recruit U.S. workers for the position, the employer should document his recruiting efforts and submit Form ETA-750 to the State Workforce Agency in his state. The SWA will forward the form to the Department of Labor.
The employer must submit USCIS Form I-129 to the USCIS to apply for the employee's visa -- the employee can not submit this form himself. This form requires information about the employee and the employer's business. The employer should submit this form at least six months before the employee is expected to start work. If the USCIS approves the application, it will send an acknowledgment to the employee, who will have to apply for a working visa at a U.S. embassy or consulate in his home country.
Working visa categories are subjected to annual quotas imposed by the USCIS. Although these quotas change from year to year, they normally do not exceed 100,000 workers per category. If you apply after the annual quota is filled, your application will be denied and you will have to wait until next year to apply. For this reason, it is best to apply early in the year.