The O visa is a non-immigrant temporary worker visa given to aliens that are considered to have outstanding special skills in athletics, business, education, arts or the sciences. Additionally, the O designation may be granted to a person who has shown a superior record of achievement in the television or motion picture industry.
There are four types of O visas: the O1A, O1B, the O2 and the 03. The 01A is for those with special skills in sciences, education, business, or athletics only. O1B visas are for people with an outstanding record of achievement in the television or motion picture industry only.
O2s are reserved for the people who accompany an 01 individual to a certain event. These people are usually classified as assistants, have their own special skill set that is not performed by the O1 and are crucial to the performance of the O1.
An O3 visa is reserved for the spouse and/or children of the O1s and O2s.
In most instances, the O1 visa is valid for up to three years. However, it may be extended one year at a time, and there are no limits to the number of times it may be extended.