答案是超过5年以后要交FICA

Please see below:

(ii) Limitation on students For any calendar year after the 5th calendar year for which an individual was an exempt individual under clause (ii) or (iii) of subparagraph (A), such individual shall not be treated as an exempt individual by reason of clause (iii) of subparagraph (A), unless such individual establishes to the satisfaction of the Secretary that such individual does not intend to permanently reside in the United States and that such individual meets the requirements of subparagraph (D)(ii).