TLDR : lose your job or quit, and you lose your visa. Zero grace period (laid off/quit on Friday, illegal immigrant by Saturday). Although the regulations do n

TLDR : lose your job or quit, and you lose your visa. Zero grace period (laid off/quit on Friday, illegal immigrant by Saturday). Although the regulations do not provide a grace period for unemployment between H-1B employers, USCIS generally approves petitions to change from one employer to the next and considers you to have maintained status if the gap is 30 days or less. CAVEAT: your (new) employer is the one that has to request the change, so if your new employer isn't organized to do this, or doesn't want to, you're in the country illegally and won't get paid. So there's a "the administration hates congress" grace period of 30 days. After that, you actually have to leave the country and cannot start work somewhere else.