For a COS (J1 to H1B), am I require to work for company A (J1 visa) until effective start date with company B (h1B visa)

Currently under a J1 visa with company A, I found a company B willing to sponsor a H-1B visa.

If company B fill a petition for a COS (J1 -> H-1B) and by chance, I get the H-1B petition approved (effective start date October 1st), am I require to work for company A (under J1 visa) until 30th September and then only switch to work to company B (under H-1B visa) ?

Or can I resign from company A at any time (i.e : July, August, September…), go back to my home country and then come back after October 1st with a new visa?

  1. If you continue to stay inside US, then you have to remain on J-1 until Sep 30 and then can start working on H-1 from Oct 1.

  2. If you leave US before COS is approved, then the only option is to get H-1 visa stamped and enter US after Sep 20th, to work on H-1 from Oct 1

  3. If you leave US after COS is approved, then you can still return on J-1 prior to Oct 1(provided you are employed w/ A) and then be on H-1 (as mentioned in 1).

  4. If you leave US after COS is approved, but are no longer employed w/ A on J-1 or return after Oct 1, then you have to return on stamped H-1 visa and can then start working on H-1

Does that answer your question?