There are two ways that an employer may obtain an L-1 visa, granted to allow certain individuals temporary residency status for the purposes of working in the United States—the blanket visa process and the regular visa process.
With the blanket visa process, an employer meeting certain criteria files documentation with the USCIS, and receives a grant of “blanket” status, meaning the employer won’t have to file individual visa applications for subsequent workers, but can submit the blanket visa along with supporting documentation to the consulate or embassy in any worker’s country of origin and obtain legal permission to bring the worker to the United States.
For employers without blanket visa approval, an application must be filed with USCIS for every additional foreign worker entering the United States. The company must initially file Form I-129, along with any documents that show that the company meets all immigration requirements. Once Form I-129 has been approved by the USCIS, the worker may seek a visa at the embassy or consulate in his or her home country. If you are already in the United States under another type of visa when the I-129 is approved, you must request a change in your non-immigrant status. As long as you file for a change of status before your current status expires, the expiration of your current status will not be a problem.