#1: Cap-gap is automatic.
The cap-gap extension is automatic for students with a pending H-1B petition that requested a change of status. This is only granted if the student was on valid OPT or STEM OPT on the day the H-1B petition was filed and their work authorization expires after April 1st.
There is no application to file with USCIS. You should obtain a new I-20 to document the cap-gap extension, and keep in mind that cap-gap extension ends September 30th.
#2: You need to be in the U.S. to change status.
If your H-1B petition is pending with a request to change status, traveling outside the U.S. will cause you to abandon the change of status. You have to be in the U.S. in order for USCIS to approve your request to change of status from F-1 to H-1B. If not, your change of status will be denied.
If the H-1B petition gets approved without the I-94, USCIS will send the approval notice to the consulate, which will require you to go for your visa interview in order to return to the U.S. on H-1B status.
#3: Act fast and act smart.
In the event that your H-1B gets denied and you are out of status, act quickly to remedy your situation.
If your H-1B petition gets denied before October 1st, you have 60 days from the date of denial to apply for a new change of status (i.e. H-4, L-1, TN, etc.), transfer to a new school, or make preparations to depart the U.S.
If your H-1B petition is still pending after October 1st, you are allowed to stay in the U.S. in a “period of authorized stay” without work authorization, but your 60-day grace period starts October 1st, regardless. So whether your H-1B petition gets denied October 24th or December 2nd, you must take action between October 1st – November 30th to change status, transfer to a new school, or make preparations to depart the U.S.