The OPT Cap-Gap Extension and pending H-1B visa 

A Cap-Gap extension allows an eligible F-1 OPT or STEM OPT student to continue to work on an expired OPT card so long as it expires after April 1^st and an H-1B visa lottery has been selected and a non-frivolous change of status from F-1 to H-1B has been filed on his or behalf. The Cap-Gap ends on September 30^th of each year and Cap-Gap Student must stop working if the H-1B has not been approved prior to October 1^st.

End of the Cap-Gap Work Authorization

F-1 OPT worker must stop working under the Cap-Gap Extension when:

Was not selected in the H-1B lottery

Denial of H-1B

Withdrawal of H-1B by the employer

Revocation of H-1B by the USCIS

The F-1 visa holder is eligible for 60-day grace period to file transfer or change of status so long as the person has not been found by the USCI violating his or her F-1 status. If the USCIS finds status violation, then the 60-day grace period will not be available for this F-1 holder and is needs to depart from the U.S. right away.

About the H-1B:

An H-1B visa allows a foreign national to live and work in the United States. The job or work must be professional and the foreign national must have a U.S. equivalent bachelor's degree in the relevant field and can work only for the H-1B sponsoring employer. An H-1B is a temporary work visa given in 3-year increment for up to 6-year.