U.S. employers may petition for skilled or unskilled alien workers to meet temporary or seasonal needs in positions for which qualified U.S. workers are not available. It is important to note that the employer’s need for such services must be temporary . There is currently an annual cap of 66,000 visas for H-2B workers. There is currently no annual cap on visas for H-2A workers.
Labor Certification
The first step to hiring an H-2 worker from outside the U.S. is for the employer to apply for a temporary labor certification with the Department of Labor. These certificates are designed to ensure that the admission of aliens to work in this country on a temporary basis will not adversely affect the job opportunities, wages, or working conditions of U.S. workers. The employer is required to file the labor certification with the I-129 petition. For specific procedures on filing, please contact The Immigration Law Offices of Rosanna Berardi.
Dependents
Dependents (spouses and unmarried children under 21 years of age) of H-2 workers are entitled to H-4 status with the same restrictions as the principal. Dependents may not be employed under the H-4 classification.
Including more than one alien in a petition
A single petition may cover multiple workers if:

  1. they will perform the same services
  2. they will work in the same location
  3. they are included on the same labor certification and,
  4. they come from places that are served by the same U.S. consulate, or, if visa exempt, they will enter at the same port of entry.

It is not necessary to identify requested H-2A beneficiaries by name (unless only a single worker is needed) if they are unnamed on the underlying labor certification. H-2B beneficiaries must be named unless circumstances (e.g. emergencies) make identification by name impossible. The number of unnamed beneficiaries must always be stated on the petition.
H-2A Agricultural worker
The H-2A classification applies to an alien coming temporarily to engage in temporary or seasonal agricultural employment .
Petition Document Requirements
Before filing this petition an employer must first apply for a labor certification from the Department of Labor to demonstrate that U.S. workers are not available and that the wages and working conditions meet regional standards. The petition (Form I-129) must be filed by a U.S. employer or an association of U.S. agricultural producers named as a joint employer on the certification. It should be filed with:

  1. An original valid temporary agricultural labor certification from the Department of Labor. If the application is denied because it is determined that U.S. workers are available but they do not subsequently appear at the work site, the petition should be filed with a copy of that agency’s denial or a certification and appeal, and evidence that qualified domestic labor is unavailable; and
  2. Copies of evidence that each named alien met the requirements as stated when applying for the labor certification.

H-2B Skilled or Unskilled Worker
The H-2B classification applies to an alien coming temporarily to engage in non-agricultural employment which is seasonal, intermittent, a peak load need, or a one-time occurrence.
Petition Document Requirements
Before filing this petition the U.S. employer must first apply for a temporary labor certification from the Department of Labor to demonstrate that U.S. workers are not available and that wages and working conditions meet regional standards. The U.S. employer should file the Form I-129 petition with:

  1. Either an original single valid temporary labor certification from the Department of Labor (or the Governor of Guam if the proposed employment is solely in Guam), indicating that qualified U.S. workers are not available and that employment of the alien will not adversely affect the wages and working conditions of similarly employed U.S. workers; or
  2. An original notice from such authority stating that such certification cannot be made, along with evidence of the unavailability of U.S. workers and of the prevailing wage rate for the occupation in the U.S, and evidence overcoming each reason why the certification was not granted; and
  3. Copies of evidence, such as employment letters and training certificates, demonstrating that each named alien meets the minimum job requirements stated in the certification.

Information courtesy of US Citizenship & Naturalization website.
Page Summary: Employers may petition for nonimmigrant status for temporary or seasonal workers under the H-2B visa category.