USCIS has regulation that addressed matters related to graduating F-1 students transitioning into H-1B employment. This regulation provided assistance, known as "cap gap" relief, for students facing status and employment eligibility gaps between the expiration of their 12-month OPT period and the start of H-1B employment. H1B employment eligibility for most graduating foreign students is dependent upon availability of  H-1B cap numbers. 

Thus, there is often a gap between the expiration of a student's OPT and the earliest allowed start date (usually October 1st) of an H1B petition filed by the employer. Without cap-gap relief, many of these students had no way to remain in the U.S. and work for many months. The regulation addressed this problem, allowing more students to transition smoothly from F-1 to H-1B status. 

The regulation also provided for a possible extension of OPT status, for an additional 17-month period (total of 29 months) for those graduates with degrees within the specified list of STEM degrees. Along with the grant of this significant privilege came new requirements for maintenance of employment during the OPT period in order to maintain status.