Answer from PM
heard I could get a OPT after my undergraduate degree and then another one after master degree, then one more after PhD. Is that right?
Yes that is correct.
After OPT, if I was given a working H1 visa, and if I left the country, I would need to go to the embassy, right? As long as I stay here, have a right status, I would not need to go back even my old, very old F-1 visa expired?
You will go to the embassy to get a visa reflecting your H1B status if your visa is not valid. If your visa and H1B is current you don't need the embassy. But if you remain in the US and your H1B expires and is renewed, you have to leave the US to go get it renewed at a consulate. But if you don't plan on traveling, you simply stay here and travel only when you need to go renew it. Most are valid for three years(could be less). When your first H1B expires here, you must leave the US for renewal.
so can someone just apply one F-1 visa and stay here for 20 years legally (not a student but work)???
No. You can't work out of campus with an F-1 visa. But you can remain here and study as long as you get an I-20 approved by your school without violating your status.
heard I could get a OPT after my undergraduate degree and then another one after master degree, then one more after PhD. Is that right?
Yes that is correct.
After OPT, if I was given a working H1 visa, and if I left the country, I would need to go to the embassy, right? As long as I stay here, have a right status, I would not need to go back even my old, very old F-1 visa expired?
You will go to the embassy to get a visa reflecting your H1B status if your visa is not valid. If your visa and H1B is current you don't need the embassy. But if you remain in the US and your H1B expires and is renewed, you have to leave the US to go get it renewed at a consulate. But if you don't plan on traveling, you simply stay here and travel only when you need to go renew it. Most are valid for three years(could be less). When your first H1B expires here, you must leave the US for renewal.
so can someone just apply one F-1 visa and stay here for 20 years legally (not a student but work)???
No. You can't work out of campus with an F-1 visa. But you can remain here and study as long as you get an I-20 approved by your school without violating your status.