Timing
A petition for Inter Partes Review may be filed after the later of either: (1) The date that is nine months after the grant of a patent or issuance of a reissue of a patent; or (2) if a post-grant review is instituted, the date of the termination of that post-grant review. See 35 U.S.C. 311(c).
Additionally, 35 U.S.C. 315(b) provides that an Inter Partes Review may not be instituted if the petition requesting the proceeding is filed more than one year after the date on which the petitioner, real party-in-interest, or privy of the petitioner is served with a complaint alleging infringement of the patent.