The general answer is “Yes,” but you do need to be aware of some risks. There is always a risk that the USCIS may deny a change-of-employer petition. Why would this happen?

It might happen for any of the reasons that the initial H-1B petition may be denied: the USCIS questions that the job is a “specialty occupation,” that a true employer-employee relationship exists (i.e. it looks like you will be working as a “contract” employee), that the employer has the financial ability to pay the offered wage, or that your degree is unrelated to the specialty occupation. 

The foundation of any H-1B petition is that the position being offered is a “specialty occupation,” requiring the minimum of a Bachelor’s degree in a particular discipline, and you hold that degree or the equivalent of that degree. If your degree is in Information Technology but you took some Economics courses, that will not qualify you, in the eyes of the USCIS, to hold a job as an economist or a statistician. The new employer may try to convince that USCIS that it will accept your degree with your coursework, but in general, both you and your new employer are asking for trouble. Stick with IT jobs!

Let’s say none of those possibilities apply to your situation. Your change-of-employer petition could also be denied if you have not properly “maintained” your H-1B status, or your current H-1B petition expired prior to the new submission. In some cases, if this happens, the USCIS will approve the petition but not the “extension of status” – this means that you would need to leave the U.S. and apply for a new H-1B visa back in your home country.

Of course, neither you or your new employer wants this to happen, so if you obey the regulations that govern H-1B status, and your new employer does the same; and you provide all the information and documentation your new employer needs for your change-of-employer petition in a timely manner, the risks are small.

Technically, you may begin working for your new employer as soon as the change-of-employer petition has arrived at the USCIS Service Center. UPS and FedEx can provide delivery confirmation. Alternatively, you and your new employer can wait until the USCIS issues the receipt notice (Form I-797C), which is usually about ten days after the petition arrives at the service center.