For most people who wish to visit the United States as a visitor for business, pleasure (such as tourism), or medical treatment, their first stop will have to be a U.S. consulate, where they will need to apply for a “B” or visitor visa. However, you may be able to avoid this if you meet all of the following criteria:
If all the above things are true of you, you may skip applying for a visa, and enter the United States under the Visa Waiver Program (VWP). (Created by Section 217 of the Immigration and Nationality Act.)
You will want to weigh the advantages and disadvantages first, however. Even people from Visa Waiver countries sometimes choose to apply for a tourist (B-2) visa first, as it offers the possibility of a longer stay and other protections.
If you enter the United States on a visa waiver, your maximum stay will be 90 days. With a B-2 tourist visa, by contrast, you will normally be allowed to stay for up to six months. What's more, with a B-2 visa, you can apply to extend your stay even longer. (See How to Extend Your Stay or Change Your Status While on a B Visa.)
People who obtain an actual B-2 tourist visa before they enter the United States will enjoy rights to:
You don't receive these basic rights if you enter the U.S. using the Visa Waiver Program. The program is based on a simple concept: You can easily enter for a 90-day stay, but when those 90 days are over, the U.S. government will have an easy time insisting that you leave.
There are limited exceptions to this 90-day stay rule. If, for example a medical or other emergency arises, or if you fear persecution in your home country, you can request a longer stay, or apply for asylum.
Also, if you become the immediate relative of a U.S. citizen (most likely by marriage, or because you are the minor unmarried child or parent of a U.S. citizen) you will probably be able to apply for a green card (adjustment of status) while in the U.S. on the VWP—on one condition. Applying for the green card cannot have been your original intent when you entered the U.S. under the VWP, or your false statements upon entry could disqualify you from receiving U.S. lawful permanent residence (a green card). Also see the caution on changing USCIS policy in this area in When Adjustment of Status Is Possible for the Immigrant Spouse of a U.S. Citizen.
Although you can avoid making a stop at a U.S. consulate to get a visa, coming to the U.S. under the VWP does require advance preparation. You will need to:
Before you arrive from a Visa Waiver country, the airline, bus, ship company, or other carrier will give you a form to fill out called an I-94W. This is mostly for the purpose of determining whether you are inadmissible to the United States. (To understand the concept of inadmissibility, see Inadmissibility: When the U.S. Can Keep You Out.)
When you arrive in the U.S., the Customs and Border Patrol (CBP) officer will take a look at your I-94W Form and other documents. The officer will see whether your name shows up in an electronic database indicating that you have overstayed any past visas or have a history of criminal, espionage, or terrorist activity.
CBP officers have the power to deny any person entry to the United States if they are not satisfied that he or she fits the criteria for entry and is admissible. They can insist that you return home immediately, without a court hearing or other second opinion. (Learn more about what to expect at the U.S. entry point or border.)
People who enter on tourist visas run this same risk upon entry. At least they, however, have given their application for entry a “trial run” past a U.S. consular official, who would probably have spotted the same issue and denied the B-2 visa right then, thus saving them a long trip to the United States.
There is one good thing about being denied U.S. entry as a Visa Waiver entrant: You can come back any time, and again request U.S. entry. That's different than many people who arrive with visas, who have to wait five years if refused U.S. entry. However, you would still have to leave the United States before returning.