The U.S. Department of Labor (DOL) is responsible for ensuring that foreign workers do not displace or adversely affect wages or working conditions of U.S. workers.
The Department of Labor states that the H-1B employer must first advertise the position at the workplace and the employer's office before hiring an H-1B non-immigrant pursuant to the H-1B visa approval.
Employers must attest that wages offered are at least equal to the actual wage paid by the employer to other workers with similar experience and qualifications for the job in question, or alternatively, pay the prevailing wage for the occupation in the area of intended employment, whichever is greater. By signing the LCA (Labor Condition Application), the employer attests that: prevailing wage rate for area of employment will be paid; working conditions of position will not adversely affect conditions of similarly employed American workers; place of employment not experiencing labor dispute involving a strike or lockout.
The law requires H-1B workers to be paid the higher of the prevailing wage for the same occupation and geographic location, or the same as the employer pays to similarly situated employees. Other factors, such as age and skill were not permitted to be taken into account for the prevailing wage. Congress changed the program in 2004 to require the Department of Labor to provide four skill-based prevailing wage levels for employers to use. This is the only prevailing wage mechanism the law permits that incorporates factors other than occupation and location.
The approval process for these applications are based on employer attestations and documentary evidence submitted. The employer is advised of their liability if they are replacing a US worker.