The USA visa application process can take several weeks or even months depending on how quickly you can get an appointment at the U.S. Embassy or Consulate. It is recommended that you start the application process as early as possible. You can apply for a USA visa even if you don’t plan on traveling to the United States in the near future. You are not required to provide specific travel dates when you apply for a USA Visa. United States visas are normally valid from 1 to up 10 years.
Foreign visitors entering the United States for tourism or leisure purposes may generally apply for the B-2 Tourist Visa. This visitor visa is required for visitors whose country of residence or origin does not yet participate in the Visa Waiver Program, but visitors from Visa Waiver Program countries are still required to hold a valid B-2 Tourist Visa for visits to the United States lasting longer than 90 days or if they plan to adjust their status to another non-immigrant visa or permanent residency (the Green Card) during their stay in the United States.
The B-2 Visa is also available to individuals entering the United States for the explicit purpose of receiving medical treatment. While the application process is similar as for tourism or leisure purposes, additional documentation is be required to establish the medical grounds for travel and the applicant's eligibility for the visa. The B-2 Tourist Visa Application Guide outlines the required documentation for a medical visa and the application process.
The maximum length of stay for holders of a B-2 Tourist Visa is six months, and the routine visitor visa is issued for the full six-month period. However, immigration officials at any United States port of entry have the discretion to determine the allowable length of stay for each visitor on a case-by-case basis. Visitors may be issued a shorter stay by an immigration officer upon entry to the United States. In this case, though, a visitor has the right to request an extension to their stay.
After entering the United States on a B-2 Visa, visitors are eligible to apply for changes in their status to another applicable visa, whether that is a temporary worker visa, a student visa, or a Green Card if eligible. The ability to update one's status in the United States is only available to visitors entering under the B-2 Tourist Visa, and not permitted under the Visa Waiver Program.