Changing an L-1 visa to a Green Card can take an average of 6 months. However, three conditions must be met for this process to commence: the foreign company must have employed the applicant for at least 1 year in a managerial position, the applicant must hold a managerial position in the United States company, and prior to the application of the green card, the U.S. company must have been running for at least 1 year.
Certain applicants with L-1 visas often qualify for faster processing of the Green Card, especially foreign executives and managers. These applicants are eligible for the category of "priority workers," and they are allowed to apply for U.S. residency without having to go through the long process of labor certification.
Labor certification is a process that requires the employer to prove to the U.S. government that there is no qualified U.S. worker who can fill that particular position that the foreigner is coming to fill. It is a tedious, expensive and complicated process that does not even guarantee a Green Card.
Although Green Cards are issued for life, the card itself expires after 10 years, after which it should be renewed by taking new pictures to print the renewed cards.