Hi,

I am on an H1b visa in the US; I have a 3 year position with a University A (my employer), from Sep 2009 to May 2012. I am taking a personal unpaid leave of absence for the second semester (Jan 2010 - May 2010). My employer has agreed to that, and I will resume working for my employer (A) in Sep 2010. I know such a leave of absence does not cancel my H1b, and is allowed by federal and California law. During my leave, I intend to visit a researcher (with which I am currently collaborating) at another US university - University B, but I will not do any work for this other university B. I will initially be out of US for a couple of months (Jan & Feb), after which I plan to visit university B for 2 or three months. My question is, what is the best way to do this. That is:

-either not require any visa from university B, and re-enter USA on my H1b visa, since I will be still in status (my employer university A will not require cancelation of the petition).

-should I maybe require a B1 - business visa - for this duration? In this case: will my H1b visa have to be canceled at the US embassy when I apply for B1, or maybe will the immigration officer cancel it when I enter the US claiming the B1 status? If it will be canceled, I will be in B1 status not H1b, but I will still be employed by University A. Then, can I use the same paperwork that I currently have from University A to reapply for the visa stamp at a US embassy and get it to return to US in the Fall of 2010? Or would the employer have to file a petition in my name again? (this is what I want to avoid, since it costs money) Will this have any effect on my status in the long run?

Can I come to the US and use a status other than H1b - say B1- leave, and then come back to H1b status?

It is a rather long and maybe more complicated question/situation... Thank you!

M