The H-1B classification applies to job candidates in a "specialty occupation." The USCIS (U.S. Citizenship and Immigration Services, part of the Department of Homeland Security) considers specialty occupations to be those requiring the theoretical and practical application of a body of highly specialized knowledge. Typically this will entail completion of a specific course of higher education. For certain individuals with specialized skills and considerable work experience, equivalency evaluations can be obtained to meet the educational requirements.

Authorization for H-1B employment is specific to the petitioning company. Additionally, the authorization extends only to the specific occupation named in the H-1B petition. The status cannot be transferred between employers without the new company first filing a petition with USCIS.

Before filing an H-1B petition, the company must file a Labor Condition Application (LCA) with the Department of Labor. The LCA defines the employer's obligations to ensure that the foreign worker does not adversely affect the wages or working conditions of United States workers. Employers with a large contingent of H-1B workers may be considered an H-1B dependent company and there are additional obligations.

Upon approval of the LCA, the H-1B petition is filed with the USCIS.  At the time of filing, employers are responsible for paying the substantial filing fees for the H-1B classification, including a one time Fraud Detection and Prevention fee ($500), and two time H-1B Education and Training Fee ($1,500).  Certain educational institutions and nonprofit or government research organizations are exempt from the Education and Training Fee, and employers with less than 26 full-time employees pay one-half of the Education and Training Fee ($750).

Candidates previously issued an H-1B visa or otherwise provided H-1B status and who have lawfully worked in the United States, may be eligible to take advantage of a "portability" provision in the law. "Portability" makes it faster to transition between H-1B employers. The portability provision permits some H-1B holders to begin their new employment with the new company upon the filing of the new H-1B petition. Candidates and companies should be sure that portability applies in their situation, and candidates are advised to continue with their present employment until portability attaches. Candidates not already holding lawful H-1B status must generally wait for USCIS approval before beginning work.

New H-1B visas are subject to annual limits per fiscal year. Currently the annual limit is 65,000 per year with an additional 20,000 available to H-1B applicants holding U.S. advanced degrees. After the limit is reached, a candidate must wait until at least the beginning of the USCIS' fiscal year (October 1) to obtain H-1B status and start work.  Due to the cap, employers often need to accelerate their H-1B process, to file as early as allowed (April 1) for the next fiscal year.  Certain educational institutions and nonprofit or government research organizations are exempt from the cap.  Special cap number allocations are also available to H-1B nonimmigrants who are nationals of Chile or Singapore pursuant to special Free Trade Agreements, although the H-1B duration is limited to only one year (renewable).

H-1B petitions may be approved for up to three years, and can be extended for up to a total of 6 years maximum stay, regardless of the number of employers. Ordinarily, after 6 years of H-1B status, the candidate must usually reside outside of the U.S. for a full year before new eligibility arises. However, in certain limited circumstances, H-1B employees who have started a green-card process may be eligible to extend their status beyond six years, in one-year increments. The employee may be eligible for extension beyond six years if either an application for labor certification or an immigrant visa petition was filed on his or her behalf at least 365 days prior to reaching the 6-year H-1B limit. NOTE: A labor certification is different from a labor condition application ("LCA"); it is often a prerequisite for an I-140 immigrant petition filed in connection with a green card.

Spouses and children of H-1B workers are eligible for dependent visas in the H-4 classification. H-4 spouses and children may not work.