The I-94 is the Arrival/Departure Record issued by the U.S. Customs and Border Protection (CBP) when you enter the United States. Why is the I-94 Arrival-Departure Record Number important? The I-94 helps prove that you entered the United States lawfully. In most cases, a lawful entry is executed with a visa or the the Visa Waiver Program (VWP). (However, there are other means to lawfully enter the United States.) Your I-94 record confirms that you have been legally admitted to the United States in a specific visa status, and for what duration of time. For most applicants, proving that you lawfully entered the U.S. is critical for eligibility to adjust status.
CBP has traditionally issued a paper I-94 that will resemble the sample below.
However, CBP more recently has begun using electronic I-94 records that can be retrieved online on the CBP website. An example is pictured below.
If you are having trouble locating your I-94, go to Where can I find my electronic I-94 record?