These workers are sometimes referred to as guest workers. The H-2A and H-2B programs are administered by U.S. Citizenship and Immigration Services (USCIS) of the Department of Homeland Security (DHS) and the Employment and Training Administration (ETA) of the Department of Labor (DOL). After receiving labor certification, a prospective H-2A or H-2B employer can submit an application, known as a petition, to DHS to bring in foreign workers. If the application is approved, foreign workers who are abroad can then go to a U.S. embassy or consulate to apply for an H-2A or H-2B nonimmigrant visa from the Department of State (DOS). If the visa application is approved, the worker is issued a visa that he or she can use to apply for admission to the United States at a port of entry. INA provisions on the admission of H-2A workers state that an H-2A petition cannot be approved unless the petitioner has applied to DOL for certification that
(1) there are not sufficient workers who are able, willing, and qualified, and who will be available at the time and at place needed, to perform the labor or services involved in the petition and 
(2) the employment of the alien in such labor or services will not adversely affect the wages and working conditions of workers in the United States similarly employed. H-2B Nonagricultural Worker Visa

The H-2B visa provides for the temporary admission of foreign workers to the United States to perform temporary nonagricultural service or labor, if unemployed U.S. workers cannot be found. For FY2017, language in the Consolidated Appropriations Act, 2017 ( P.L. 115-31 ) provides for the issuance of H-2B visas beyond the statutory cap under certain conditions (see " Legislative Activity "). Major guest worker reform legislation was last considered in the 113 th Congress. More recent guest worker bills have proposed changes to the existing H-2A and H-2B visas. Legislative action on guest worker programs in recent years has focused on the H-2B visa, specifically on the statutory cap and H-2B regulatory provisions. The Consolidated Appropriations Act, 2016 ( P.L. 114-113 ) included an H-2B returning worker provision, providing that a returning H-2B worker who had been counted against the 66,000 cap in FY2013, FY2014, or FY2015 would not be counted again in FY2016. Policy Considerations

Guest worker programs generally try to achieve two goals simultaneously: to be responsive to legitimate employer needs for temporary labor and to provide adequate protections for U.S. and foreign temporary workers. The balancing of broad guest worker program goals is reflected, in practice, in the particular provisions that H-2A and H-2B proposals include on a range of component policy considerations, such as program administration, the labor market test, and wages, among others. The H-2A visa is not numerically limited. More direct questions about legalization of unauthorized workers in the United States also arise in connection with guest worker programs.
Under current law, certain foreign workers, sometimes referred to as guest workers, may be admitted to the United States to perform temporary service or labor under two temporary worker visas: the H-2A visa for agricultural workers and the H-2B visa for nonagricultural workers. Both programs are administered by the Department of Homeland Security (DHS) and the Department of Labor (DOL).
The H-2A and H-2B programs—and guest worker programs broadly—strive both to be responsive to legitimate employer needs for temporary labor and to provide adequate protections for U.S. and foreign temporary workers. There is much debate, however, about how to strike the appropriate balance between these goals.
Bringing workers into the United States under either the H-2A or H-2B program is a multiagency process involving DOL, DHS, and the Department of State (DOS). As an initial step in the process, a prospective H-2A or H-2B employer must apply for DOL labor certification to ensure that U.S. workers are not available for the jobs in question and that the hiring of foreign workers will not adversely affect the wages and working conditions of U.S. workers. After receiving labor certification, the employer can submit an application, known as a petition, to DHS to bring in foreign workers. If the application is approved, a foreign worker who is abroad can then go to a U.S. embassy or consulate to apply for an H-2A or H-2B nonimmigrant visa from DOS. If the visa application is approved, the worker is issued a visa that he or she can use to apply for admission to the United States at a port of entry.
Major guest worker reform legislation was last considered in the 113th Congress. Since then, guest worker bills typically have proposed to change particular aspects of the existing H-2A and H-2B visas.
Legislative action in recent years has focused on the H-2B visa, specifically the statutory numerical limitation on the visa and H-2B regulatory provisions. Regarding the H-2B numerical limitation, the Consolidated Appropriations Act, 2016 (P.L. 114-113) provided that a returning H-2B worker who had been counted against the statutory cap in FY2013, FY2014, or FY2015 would not be counted again in FY2016. This provision expired at the end of FY2016. For FY2017, related language in the Consolidated Appropriations Act, 2017 (P.L. 115-31) provides for the issuance of H-2B visas beyond the statutory limit under certain conditions.
Guest worker proposals may contain provisions on a range of component policy issues. Key policy considerations for Congress include the labor market test to determine whether U.S. workers are available for the positions, required wages, and enforcement. The issue of unauthorized workers also arises in connection with guest worker programs.