Most nonimmigrant classifications require aliens to prove they have a residence abroad that they do not intend to abandon, and that they do not have the intention to immigrate permanently to the US. This implies that taking steps towards U.S. permanent residence will, in most cases, jeopardize an alien's chances of acquiring a nonimmigrant visa or nonimmigrant status. The H-1B category, however, benefits from the doctrine of "dual intent." Dual intent allows a nonimmigrant to obtain or continue in a particular nonimmigrant status even though steps may have been taken towards obtaining U.S. permanent residence.
Regulations at 8 C.F.R. § 214.2(h)(16)(i) state:
The approval of a permanent labor certification or the filing of a preference petition for an alien shall not be a basis for denying an H-1C or H-1B petition or a request to extend such a petition, or the alien's admission, change of status, or extension of stay. The alien may legitimately come to the US for a temporary period as an H-1C or H-1B nonimmigrant and depart voluntarily at the end of his or her authorized stay and, at the same time, lawfully seek to become a permanent resident of the United States.