The S-6 visa is a non-immigrant visa which allows travel to United States for individuals who are witnesses, informants, or otherwise supplying critical information regarding a terrorist organization and who will be placed in danger by supplying that information to US officials. The S-6 visa was created by Congress on October 1, 2001 in response to the September 11 terrorist attacks. Individuals must also be eligible for a cash reward under the State Department Basic Authorities Act of 1956
The maximum duration of stay for a person admitted under an S-6 visa is 3 years, and a maximum of 50 individuals may be admitted in a fiscal year. No S-6 visas have been issued since 1996. S-6 visa holders may apply for permanent residence if they have "substantially contributed" to prevention of a terrorist attack or apprehension of an individual involved in terrorist activities.