Hi,

What will be my visa status during Cap Gap and when does my employer has to file for my H1B?

Background: Completed a certificate course and eligible for 12 months OPT.
OPT starts April 2015 and ends April 2016. Am I eligible for Cap Gap and what will my status during Cap Gap (meaning can I continue working). When does my employer has to file for my H1B?

Cap gap is for if your OPT expires or your F1 status expires, while your H1b has already been filed but H1b status has not yet started.

There is a limited number of cap-subject H1b's each fiscal year. The fiscal year starts on October 1, so e.g. if you get one of the H1b's under FY 2016's cap, the earliest you can start is October 1, 2015. H1b can be applied for at most 6 months early, which means if you will start on October 1, the earliest you can apply is April 1. Applications are usually accepted on a first-come first-serve basis; but when the cap is reached in the first few days of April, they do a lottery of the ones received in those days. In the last two years, demand has been so high that there have been lotteries, which basically means the company must file on April 1st or so, and even then it does not guarantee you get a spot.

If your company is ready to file for you for this year on April 1, 2015, then you get an attempt for this year. The preparations take maybe a few weeks, so if they haven't started, it's already too late for this year.

Then for next year, your company needs to file for you on April 1, 2016. I'm assuming that by OPT ending in "April 2016" I am assuming some date in the middle of April. If so, if they file on April 1, then by the fact that they have filed your H1b before your OPT expires, your OPT is automatically extended past its expiration, until either your H1b is denied or rejected, or until September 30. That is what is known as "cap gap". During this time you will still be in F1 status, on OPT.