People coming to the U.S. to supply critical information to federal or state authorities where it has been determined that their presence in the U.S. is essential to the success of a criminal investigation or prosecution. People coming to the U.S. to provide critical information to federal authorities or a court, who will be in danger as a result of providing such information, and are eligible to receive a reward for the information. V. Spouses and children of U.S. lawful permanent resident petitioners who have already waited three years for the approval of their visa petition or for an immigrant visa to become available. Time Limits on Nonimmigrant Visas Just as nonimmigrant visas vary in purpose, they also vary as to how long they last. Each nonimmigrant visa is given an expiration date according to what the law allows for that particular category.
Many nonimmigrant visas are good for up to five years.
Most can also be extended a certain number of times. The number and length of these extensions also vary according to the visa category. Keep in mind that the expiration date on your visa does not show how long you can stay in America once you arrive. It only indicates the period of time during which you have the right to enter the United States. When you enter the United States on a valid nonimmigrant visa, you will be given a small white or green card called an I-94 card.