U.S. employers in various industries argue that they need to hire foreign workers to perform low-skilled jobs. A threshold question about importing temporary lower-skilled workers, sometimes referred to as guest workers, is whether U.S. employers need foreign workers for lower-skilled positions, or whether there is a sufficient number of available U.S. workers who could fill these jobs. This question gains salience in times of high U.S. unemployment. The issue of whether U.S. employers need foreign workers is often stated in terms of whether there are domestic labor shortages in particular industries and occupations. Questions about the existence of labor shortages are difficult to answer definitively because of various factors. The issue of labor shortages in seasonal agriculture, in particular, has been a longstanding concern and is receiving renewed attention. The farm labor shortage issue, however, is surrounded by many unanswered questions, including the following: Would more U.S. workers be willing to become farm workers if wages were raised and the terms of work were changed? If so, would such wage and other changes make the U.S. agricultural industry uncompetitive in the world marketplace? Alternatively, would there be an adequate supply of authorized U.S. farm workers if new technologies were developed and implemented? In the past, guest workers have been imported to address U.S. worker shortages during times of war. During World War I, for example, tens of thousands of Mexican workers performed mainly agricultural labor as part of a temporary worker program. The controversial Bracero program, which began during World War II and lasted until 1964, brought several million Mexican agricultural workers into the United States. At its peak in the late 1950s, the Bracero program employed more than 400,000 Mexican workers annually. Today, the United States imports guest workers in much smaller numbers to perform temporary agricultural and nonagricultural labor. In current guest worker programs, issues of need for foreign workers are addressed on an individual basis through a process of labor certification. Guest worker programs remain controversial. Some view them as a necessary source of legal workers and call for their reform and expansion. Others view them, in their current form, as "inherently abusive" and argue that if they are to be allowed to continue operating, they must be thoroughly overhauled. This report discusses existing visa programs for temporary lower-skilled workers, including regulatory changes since 2008. It covers legislative efforts to reform current programs and to create new guest worker visas. It further identifies and explores key policy considerations to help inform congressional action on guest worker programs. The Immigration and Nationality Act (INA) of 1952, as amended, enumerates categories of aliens, known as nonimmigrants, who are admitted to the United States for a temporary period of time and a specific purpose. Nonimmigrant visa categories are identified by letters and numbers, based on the sections of the INA that established them. Among the major nonimmigrant visa categories is the "H" category for temporary workers. The H category includes H-2A and H-2B visas for guest workers, as well as visas for higher-skilled temporary workers. Foreign nationals can also perform lower-skilled temporary work on certain other nonimmigrant visas. The INA, as originally enacted, authorized an H-2 nonimmigrant visa category for foreign agricultural and nonagricultural workers who were coming temporarily to the United States to perform temporary services (other than services of an exceptional nature requiring distinguished merit and ability) or labor. The 1986 Immigration Reform and Control Act (IRCA) amended the INA to subdivide the H-2 program into the current H-2A agricultural worker program and H-2B nonagricultural worker program and to detail the admissions process for H-2A workers. The H-2A and H-2B programs are administered by the Employment and Training Administration (ETA) of the Department of Labor (DOL) and U.S. Citizenship and Immigration Services (USCIS) of the Department of Homeland Security (DHS). While there are many differences between the H-2A agricultural worker program and the H-2B nonagricultural worker program, the process of importing workers under either program entails the same steps. Employers who want to hire workers through either program must first apply to DOL for labor certification, as discussed in the next section. 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. In both the H-2A and H-2B programs, there is a tension between providing protections to U.S. and foreign workers on the one hand and making the programs responsive to legitimate employer needs on the other. While these competing interests are longstanding, the current environment—with relatively high levels of U.S. unemployment; discussions about expanding the E-Verify electronic employment eligibility verification system (as discussed below); and concerns about shortages of legal workers, especially in agriculture—has heightened the tensions. DOL's ETA is responsible for administering the labor certification process under the H-2A and H-2B programs. Under both programs, employers submit applications in which they request the certification of a particular number of positions. 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, qualified … and available at the time of application for a visa and admission to the United States and at the place where the alien is to perform such skilled or unskilled labor, and (2) the employment of such alien will not adversely affect the wages and working conditions of workers in the United States similarly employed. There is no equivalent statutory labor certification requirement for the H-2B program. The INA, however, does contain some related language. For example, it defines an H-2B alien, in relevant part, as an alien "who is coming temporarily to the United States to perform other temporary service or labor if unemployed persons capable of performing such service or labor cannot be found in this country." The H-2B labor certification requirement instead appears in DHS regulations. These regulations state: The petitioner may not file an H-2B petition unless the United States petitioner has applied for a labor certification with the Secretary of Labor ... and has obtained a favorable labor certification determination ... The H-2A and H-2B labor certification requirements are intended to provide job, wage, and working conditions protections to U.S. workers. They are implemented in both programs through a multifaceted labor certification process that requires prospective H-2A and H-2B employers to conduct recruitment for U.S. workers and offer a minimum level of wages and benefits that varies by program. Table 1 provides summary information on H-2A and H-2B labor certification applications. The position certified number represents the number of positions for which employers can apply to DHS to fill with foreign workers. Typically, however, employers petition for a smaller number of workers. The H-2A program allows for the temporary admission of foreign workers to the United States to perform agricultural labor or services of a seasonal or temporary nature, provided that U.S. workers are not available. In general, for purposes of the H-2A program, work is of a temporary nature where the employer's need for the worker will last no longer than one year. Thus, an approved H-2A visa petition is generally valid for an initial period of up to one year. An employer can apply to extend an H-2A worker's stay in increments of up to one year, but an alien's total period of stay as an H-2A worker may not exceed three consecutive years. An alien who has spent three years in the United States in H-2A status may not seek an extension of stay or be readmitted to the United States as an H-2A worker until he or she has been outside the country for three months. As discussed above, an employer who wants to import H-2A workers must first apply to DOL for a certification that (1) there are not sufficient U.S. workers who are qualified and available to perform the work; and (2) the employment of foreign workers will not adversely affect the wages and working conditions of U.S. workers who are similarly employed. Prospective H-2A employers must attempt to recruit U.S. workers and must cooperate with DOL-funded state employment service agencies (also known as state workforce agencies) in local, intrastate, and interstate recruitment efforts. Under the H-2A program's fifty percent rule , employers are required to hire any qualified U.S. worker who applies for a position during the first half of the work contract under which the H-2A workers who are in the job are employed. Among the other H-2A labor certification requirements, employers must provide a "three-fourths guarantee"; that is, they must guarantee to offer workers employment for at least three-fourths of the contract period. As discussed below, H-2A employers must pay their H-2A workers and similarly employed U.S. workers the highest of several wage rates and must also provide workers with housing, transportation, and other benefits, including workers' compensation insurance. No health insurance coverage is required.