USCIS accepts H-1B applications subject to the cap up to 180 days before the beginning of the government fiscal year that starts on October 1. Thus, the first day of filing for cap subject H-1Bs is April 1 of each year.  Questions arise regarding what is supposed to happen when a student working on Optional Practical Training (OPT) has their work authorization run out before October 1.  This time period is called the "cap-gap."
USCIS addressed the "cap-gap" of employment authorization between OPT ending on or after April 1 but not lasting till the October 1 start date by extending the authorized period of employment for all F-1 students who have a properly filed H-1B petition (filed under the cap for the next fiscal year) pending with USCIS. If USCIS approves the H-1B petition, the student receives a work extension that enables him/her to remain in the United States until the requested start date indicated on the H-1B petition, i.e., October 1 of that year.
The student's Designated School Official (DSO) should process the Cap-Gap Extension I-20 on behalf of the student. The student will need to provide the I-129 receipt for the H-1B application to the DSO so an extended I-20 may be issued.
The cap-gap extension of status applies to all F-1 students in all fields of study with pending H-1B petitions (whether the 12 month card or STEM extension). For employment authorization to be extended during the cap-gap, the student must have an approved period of post-completion or 17 month extension with a future OPT end date. Â Stated another way, the OPT end date must always fall after the date the H-1B petition was filed.
A student who does not have post-completion OPT or 17-month extension, or whose post-completion OPT or 17-month extension has expired before the H-1B petition was filed, will have the duration of status extended as a grace period for 60 days, but will not have cap-gap work authorization.