The H-1B program allows skilled foreign-born individuals to work in the United States. The annual quota on new issuances of H-1B status fell from 195,000 to 65,000 in fiscal year 2004. This cap did not apply to new employees of colleges, universities, and non-profit research institutions. Existing H-1B holders seeking to renew their status were also exempt from the quota. Using a triple difference approach, this paper demonstrates that cap restrictions significantly reduced the hiring of new H-1B workers in for-profit firms relative to what would have occurred in an unconstrained environment. Declines were most pronounced at the top and bottom quintiles of the wage distribution. Restrictions did not reduce hiring of new H-1B workers from India, in computer-related occupations, or at firms using the H-1B program intensively.