If the immigration officer at the border of the U.S. allows the alien to be admitted into the U.S., the officer will issue an I-94 card and the alien obtains a legal status to remain in the United States for the specific purpose or purposes designated by the visa for a limited time. For example, if an alien holds a B-1 limited business visa and is admitted to the United States, the alien now has a B-1 legal status to remain in the United States to conduct limited business activity. The duration of authorized stay for the alien is shown on the I-94 card. A legal status allows the alien to remain in the US for the intended purpose of the visit, while a visa allows an alien to apply for admission into the United States for a specific purpose. Status and a visa are separate concepts and one does not necessarily have to have to do with the other. Each can and often have separate expiration dates. For example, an alien holds a B-1 visa to do business in the United States temporarily and seeks admission to US based on that visa which expires in three months. When a visa is valid for a specific period, the alien has to apply for admission into the United States within that period. In our example, the alien has three months to apply for admission into the U.S. The alien applies for admission to the U.S. at the border one month after his visa is issued. His visa does not expire until two months from the time he is applying for admission into the U.S. The border officer grants the application and gives the alien an I-94 showing that the alien has a B-1 status to do business in the US for a temporary period of six months. In this case, the alien's visa expires four months before his legal status expires.

Status only remains valid if the alien remains in the US for the duration of the authorized stay as evidenced by the I-94. Once an alien leaves the US, the alien's legal status is cancelled even though there is time left before the expiration date of the legal status. For readmission into the United States, the alien needs to have a valid visa. In the example above, if the alien left the United States after his visa expired and prior to the expiration of his status (i.e., between two and six months after his application at the border for admission is granted), the alien would have to apply for a new visa to regain admission to the United States for the same purpose or any other purpose. If he left and sought to return prior to the expiration of his visa (i.e. less then two months after his admission) and his visa allows for multiple entries, he would not have to apply for a new visa to come back to the United States prior to the expiration of his visa.

As noted above, a visa is only for purposes of admission into the United States, not for purposes of remaining in the United States. Remaining in the United States is strictly covered by legal status as evidenced by the I-94. Therefore, if an alien's legal status expired and the alien is still in the United States, the alien is in the United States unlawfully even though his visa may not have expired. An alien in this situation must immediately seek to regain a valid legal status to avoid deportation or other serious consequences.

For more information on non-immigrant visa, please click on the following links:
What is a non-immigrant visa?
Who needs a non-immigrant visa?
What are some common non-immigrant visas?
What is the difference between visa and non-immigrant status?
Consulate process for non-immigrants
Entry into the United States
Visa Waiver Pilot Program (VWPP)
Attorney Fees