This may seem like a simple question but it is often misunderstood. A visa is a document placed or stamped in an individual’s passport. It is an entry document. The visa stamp alone is not authorization to remain in the United States. The visa stamp must be valid in the specific category under which the person wishes to enter the U.S. A visa is obtained from an U.S. Embassy or U.S. Consulate abroad – may not be obtained in the United States.