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. Most nonimmigrant visas can be extended a certain number of times. The number and length of these extensions also vary according to the visa category and this, too, is fixed by law. In the individual nonimmigrant visa-related chapters of this book, we will tell you the length of time each visa lasts and how many extensions are available. You may need to look at a combination of factors, such as:
• the expiration date of your petition or certificate of eligibility, if one is required
• the expiration date of your visa
• the number of entries permitted on your visa
• the date stamped on your I-94 card
• the expiration date of your passport (rules are different for Canadians— see Chapter 5), and
• the expiration date of your status.