When you visit the USA as a non-US citizen or non-resident you need to follow the entry and exit rules very carefully. The United States has a very strict set of procedures to go into and leave the country and it is important that you, as a visitor, pay attention to the procedure and keep within the law. This will save any unnecessary questioning or delays this time you are in the United States, and also any times in the future when you visit the country. The I-94 card is one way in which the United States monitors and tracks the arrival and departure of temporary visitors, immigrants and others.
You receive the I-94 card when you arrive in the United States. It is also called the I-94 form or permit, or the arrival and departure record. This card is given to each and every person who comes into the States as a non-immigrant and non-resident. You need to fill out the card when you arrive into the United States. When you pass through immigration the official at the desk will staple part of the card into your passport.
This I-94 card is important because it is a documentation of the date of your arrival into the United States. It also documents the date you leave America. When you are in the United States you should try to take care of the I-94 document, to save yourself trouble and inconvenience. You return the form when you leave the United States.
If you happen to lose the I-94 card, or your passport, while you are traveling in the United States you must have both documents replaced as soon as possible. You can file a report with the police and then request a form to document the replacement of your document. If airport staff do not take your I-94 back when you leave the United States ask them to take it from you as you should submit your form as soon as you exit the country. If you still have the document when you arrive home you need to send it back with proof that you left the country, such as an arrival stamp from your home country in your passport or your used boarding pass from your flight. If you have any questions when you are leaving the US, ask airline staff for advice.