Change of Status from H1B to F1

[h1behelp]

Hi, I want to change from H1B to F1 because of bad economy or lay off. My questions are;
1. What would be my status during my pending COS (H1 to F1) petition provided I have filed COS before getting laid off? I heard COS approval may take up 6 months.
2. Do I have to go out side of US because approval may take up to 6 months?

[DMX17]

You will be a period of authorized stay by the Attorney General for the time your COS is pending. You can stay here till your case is adjudicated.

[kabkaba]

You cannot work or study during that period.

[h1behelp]

You will be a period of authorized stay by the Attorney General for the time your COS is pending. You can stay here till your case is adjudicated.

Thank you so much for your answer!

Question: If I want to come again to H1 from F1 later on, do I have to go through the lottery system again if chose to go with a different employer?

If my COS (H1B to F1) petition does not get approved, what options I'd have at that time?