In most cases a citizen of a foreign country who seeks to enter the United States generally must first obtain a U.S. visa, which is placed in the traveler’s passport, a travel document issued by the traveler’s country of citizenship.
There are more than 20 nonimmigrant visa types for people traveling to the United States temporarily. There are many more types of immigrant visas for those coming to live permanently in the United States. The type of visa you need is determined by the purpose of your intended travel. For an overview of visa types, please see Types of Visas for Temporary Visitors or Visa Types for Immigrants.
Please use the illustrated guide below to learn how to read your new nonimmigrant visa (for travel to the U.S. as a temporary visitor). In addition, as soon as you receive it, check to make sure information printed on the visa is correct (see below). If any of the information on your visa does not match the information in your passport or is incorrect, please contact the nonimmigrant visa section at the embassy or consulate that issued your visa.
The period of visa validity is determined by the consulate and is country specific. The dates on the Form DS-2019 or the Form I-20 do not necessarily determine the dates of validity on the visa.
A visa does not guarantee entry into the U.S. A visa allows a foreign citizen to travel to the U.S. port of entry, and the Department of Homeland Security U.S. Customs and Border Protection (CBP) immigration inspector authorizes or denies admission to the United States. See Admissions on the CBP website.
No. If the Department of Homeland Security, Customs and Border Protection Immigration Officer at the port of entry (generally an airport) admitted you into the United States for a specific period of time, s/he will note your authorized period of stay on your admission stamp, Form I-94 and Arrival/Departure Record. You will be able to remain in the United States during your authorized period of stay, even if your visa expires during the time you are in the United States. If you are issued a paper Form I-94, this will document your authorized stay and is the official record of your permission to be in the U.S. It is very important to keep inside your passport.
A visa does not guarantee entry into the United States, but allows a foreign citizen coming from abroad, to travel to the United States port of entry (generally an airport or land border) and request permission to enter the United States. The Department of Homeland Security, U.S. Customs and Border Protection (CBP) officials have authority to permit or deny admission to the United States, and determine how long a traveler may stay. At the port of entry, upon granting entry to the United States, the Department of Homeland Security, U.S. immigration inspector, provides you an admission stamp or paper Form I-94, Arrival/Departure Record in your passport. On this admission stamp or paper form, the U.S. immigration inspector records either a date or "D/S" (duration of status). If your I-94 contains a specific date, then that is the date by which you must leave the United States. Your admission stamp or paper Form I-94 is very important to keep in your passport, since it shows your permission to be in the United States. Review information about Admission on the CBP Website. Also, see Duration of Stay.
Yes, you will have to go through the whole visa application process each time you want to apply for a visa, even if your visa is still valid. There are some situations where a visa applicant may not need to be interviewed when renewing his/her visa. See the U.S. Embassy website for more information.
Some visa applications require further administrative processing, which takes additional time after the visa applicant's interview by a Consular Officer. Applicants are advised of this requirement when they apply. Most administrative processing is resolved within 60 days of the visa interview.
A visa must be valid at the time a traveler seeks admission to the U.S., but the expiration date of the visa (validity period/length of time the visa can be used) has no relation to the length of time a temporary visitor may be authorized by the Department of Homeland Security to remain in the United States. Persons holding visas valid for multiple entries may make repeated trips to the U.S., for travel for the same purpose, as long as the visa has not expired, and the traveler has done nothing to become ineligible to enter the U.S. at port of entry.
No. If your visa is still valid you can travel to the United States with your two passports, as long as the visa is valid, not damaged, and is the appropriate type of visa required for your principal purpose of travel. (Example: tourist visa, when your principal purpose of travel is tourism). Both passports (the valid and the expired one with the visa) should be from the same country and type (Example: both Uruguayan regular passports, both official passports, etc.). When you arrive at the United States port of entry (POE) the Customs and Border Protection Immigration Officer will check your visa in the old passport and if s/he decides to admit you into the United States they will stamp your new passport with an admission stamp along with the annotation "VIOPP" (visa in other passport). Do not try to remove the visa from your old passport and stick it into the new valid passport. If you do so, your visa will no longer be valid.
Most information on this page is from the U.S. Department of State "About Visas - The Basics" webpage. Some information may have been modified or added.