Grad student visas are a whole animal. Transitioning from an F1 to a H1b, or green card, is fraught with it's own complications. That's why most graduate school

Grad student visas are a whole animal. Transitioning from an F1 to a H1b, or green card, is fraught with it's own complications. That's why most graduate schools are stacked international students. Americans and permanent residents wouldn't put up with it. And that is by design.