Someone I know (nationality French) has accepted a six-month post-doctoral fellowship in the United States. The hosting institute will sponsor a J-1 visa; my understanding is that J-1 visas are much quicker to process than H-1B visas, and since she should start as soon as possible, they opt for J-1. A J-1 Research Scholar visa has the following limitations:
Professor and Research Scholars must:
(...)
Not have participated in a J-Visa program for all or part of the 12-month period immediately preceding the start date of a professor or research scholar program unless they meet one of the following exceptions:
(...)
The participant's prior physical presence in the U.S. on a J-visa program was less than six months in duration
If she physically leaves the United States one week before the end of her contract (having been in the US for 5 months, 3 weeks), for example to attend a conference in Europe or for working from home, can she still apply for a new post-doctoral fellowship (NB: I'm not talking about an extension of the existing post-doc) at a new J-1 research scholar visa, or will a H-1B visa be the only route still accessible for a new post-doc?