Section 42.202 - Time for filing(a) A petition for a post-grant review of a patent must be filed no later than the date that is nine months after the date of the grant of a patent or of the issuance of a reissue patent. A petition, however, may not request a post-grant review for a claim in a reissue patent that is identical to or narrower than a claim in the original patent from which the reissue patent was issued unless the petition is filed not later than the date that is nine months after the date of the grant of the original patent. 77 FR 48729 , Aug. 14, 2012, as amended at 84 FR 51982 , Oct. 1, 2019