In most cases, the answer is no – once a foreign national has obtained H-1B status, they do not need to go through the lottery again to change employers. 

The new employer files a petition on their behalf, and they go to can work in H-1B status for the new employer seamlessly once the petition has been receipted by the USCIS. In addition to already being in H-1B status, the worker must never have been employed in a manner outside of their authorization; and have been lawfully admitted to the U.S. If these three conditions are met, it is very likely that the change of employer petition will be approved by USCIS, so changing to the new employer will work. 

Usually, it takes a week or 10 days for the hard-copy receipt notice to arrive, but if the worker has proof of delivery to the USCIS, they can use that as evidence that the petition has been received by USCIS. 

There is always a risk that the USCIS may deny the change-of-employer petition. If that happens, the foreign national must cease working immediately and make plans to leave the U.S. or find a new H-1B job before their 60-day grace period expires. 

What would happen, though, if a person spent a few years in H-1B status in the U.S., and then returned to their home country and remained there for a few years, and then another U.S. employer wants to hire them and file for an H-1B on their behalf? If their previous H-1B time falls outside a period of seven years, the new employer would need to go through the yearly H-1B registration and lottery process on their behalf.

And of course, if a person accumulates a full six years on H-1B – the time limit for this visa class – they will need to leave the U.S. and remain outside for a full year before another H-1B can be filed on their behalf; and in such a case, that would be a fresh, new H-1B requiring registration and the lottery.