After you have entered the US using your visa, you must maintain legal status. Legal status allows you to legally stay in the US until the expiration date stamped in your passport or on your I-94 form, the white piece of paper commonly stapled in your passport. Earlier this year, CBP (Customs and Border Patrol) digitized the I-94 process and one does not get a paper anymore. However, the date in the passport still dictates how long you can stay. When this date is up, so is your legal status.

Please note, your visa may have a way longer expiration date than the stamp in the passport. This only means that you can leave and enter the US with the same visa up until the visa expiration date.