The H-1B ‘non-immigrant’ temporary foreign guest worker program is called a valuable tool for employers to attract and retain the “best and brightest” immigrants in the science, technology, engineering, and math (STEM) fields. Because employers may petition for permanent residence for their H-1B employees, the visa is sometimes described as a “bridge to immigration” that will keep the smartest foreign STEM workers in the U.S. permanently and thus improve the nation’s competitiveness. In part that’s how Senators Hatch, Rubio, Coons and Klobuchar explain their new bill – known as the “I-Squared Act” – that would more than quadruple the size of the H-1B program.

However, for the biggest users of the program, this view is false: In 2012, the 10 employers receiving the largest number of H-1B visas were all in the business of outsourcing and offshoring high-tech American jobs. Many of the jobs that went to H-1B workers should have instead gone to U.S. workers, but employers are not required to recruit them before applying for an H-1B, and can even replace their U.S. workers with H-1Bs. The top 10 H-1B employers were granted an astonishing 40,170 visas; nearly half the total annual quota. The table also shows each firm’s immigration yield: the ratio of permanent residence applications to new H-1B petitions for these companies. It is evidence of the companies’ intention to hire and keep their H-1B workers in the country permanently.

There are two reasons these firms hire H-1Bs instead of Americans: 1) an H-1B worker can legally be paid less than a U.S. worker in the same occupation and locality; and 2) the H-1B worker learns the job and then rotates back to the home country and takes the work with him. That’s why the H-1B was dubbed the “Outsourcing Visa” by the former Commerce Minister of India, Kamal Nath. Rather than keeping jobs from leaving our shores, the H-1B does the opposite, by facilitating offshoring and providing employers with cheap, temporary labor – while reducing job opportunities for American high-tech workers in the process. The I-Squared Act does nothing to protect against this, while vastly expanding the size of a deeply flawed program that accelerates the offshoring of American high-tech jobs and reduces America’s future capacity to innovate.

MORE: The full list of H-1B employers for 2012 is available from ComputerWorld.