A category under the U.S. Immigration and Nationality Act by which aliens can enter the U.S. for three years if they work in a specialized field and their employers cannot fill the position locally. The three years may also be extended to six years. Programmers and other technicians in the computer field enter the U.S. under this status. In 2000, there were estimates of as many as 460,000 H1B employees in the U.S. Also in 2000, the cap for H1B visas was raised from 115,000 to 195,000 per year, and it allowed an extension of H1B beyond six years if the person was in the process of securing a green card. At the end of 2003, the number reverted back to the original 65,000 worker ceiling.