After getting O1 visa, on admission for the first time the alien may be permitted to work and stay in the United States for a maximum period of three years. However, the duration of O1 visa is determined by the time period the worker require to complete his/her duties with the sponsor. Scrutinizing evidences of the occupation related activity or event, the United States Citizenship and Immigration Services (USCIS) will decide the duration of O1 visa. The outsider can enter into the U.S. 10 days before the duration of O1 visa starts and he/she will get 10 days of grace period to leave the U.S. after the last date of the visa expires.
The duration of O1 visa may be extended up to one year each time, if the petitioner requests the USCIS upon showing valid reasons that the employee has to continue work in the U.S. to complete the duties for which he/she had admitted.
However, if the worker is changing a job or a new designation is offered by the same employer, it would be considered as a new activity. On filing a petition, requesting to extend the duration of O1 visa, the alien may be granted a new three year O status.
Needless to mention, the duration of O1 visa can be extended or the status of the visa can be changed only when the beneficiary follows the rules and regulations of the USCIS. Violation of immigration rules may put the beneficiary at risk and he/she may have to depart the U.S. before the duration of O1 visa ends.