H-1B Cap Gap Extension
H-1B is a work visa sponsored by an employer. Students may transition from OPT authorization to H-1B. While there are a limited number of H-1Bs available each year, for most employers this limit is often called the “H1-B cap”. New H-1Bs become effective each October 1, but the application period for most employers begins six months earlier, April 1. The “cap gap” occurs when a student’s F-1 status and/or OPT expire before their approved H1-B begins October 1.
The H-1B Cap Gap Extension allows students with pending or approved H-1B petitions to remain in the U.S. until the start date of their approved H-1B employment period, even if the OPT authorization and/or F-1 grace period would have otherwise expired before October 1.
You can read more details on the Cap-Gap Regulations here.