The initial period of stay of O-1 visa can be granted up to 3 years. However, the length of the status is determined by the length of time needed for the alien to perform his duties or activities with the petitioning employer. This period may be extended at one-year increments thereafter, upon evidence showing that the alien’s continued presence would be required to complete the event or activity for which they were admitted. Unlike H1B, there is no maximum of years limitation for O visa.
As an O nonimmigrant, the beneficiary may be admitted to the United States for the validity period of the petition, plus a period of up to 10 days before the validity period begins and 10 days after the validity period ends. The beneficiary may only engage in authorized employment during the validity period of the petition.