8 CFR 214.2(o)(2)(iv)(D)
(D) Amended petition. The petitioner shall file an amended petition on Form I-129, with fee, with the Service Center where the original petition was filed to reflect any material changes in the terms and conditions of employment or the beneficiary’s eligibility as specified in the original approved petition. In the case of a petition filed for an artist or entertainer, a petitioner may add additional performances or engagements during the validity period of the petition without filing an amended petition, provided the additional performances or engagements require an alien of O-1 caliber.