There is no maximum total stay limit on an O-1A visa.The initial grant is for up to 3 years, followed by 1-year extensions. These extensions can be renewed indefinitely, as long as you continue to meet the O-1A requirements and remain in the same line of work.There is also no minimum or maximum number of days you must be physically present in the U.S. each year under O-1A, as long as your employment and status remain valid.