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Post-Grant Review and Inter Partes Review

When a company or inventor obtains a patent from the U.S. Patent and Trademark Office (USPTO), this often is not the end of the story. In many cases, third parties will challenge the validity of patents issued by the USPTO. Under the America Invents Act (AIA), which was signed into law in 2011, there are two primary methods for challenging a registered patent. These are (i) post-grant review, and (ii) inter partes review.

Greenblum & Bernstein, P.L.C.’s Post-Grant Patent group is devoted to representing clients in post-grant review (PGR) and inter partes review (IPR) proceedings before the USPTO’s Patent Trial and Appeal Board (PTAB). The attorneys in this group have well over 100 years of combined experience in disputed patent matters, including decades of prior experience serving as judges on the PTAB. This experience makes our Post-Grand Patent group uniquely qualified to represent both patent owners and third-party petitioners in PGR and IPR proceedings, and the group has an extensive track record of both successfully defending and challenging registered patents.

Post-Grant Review Proceedings

Post-grant review proceedings can be used to challenge the validity of patents with a priority date no earlier than March 16, 2013. A PGR petition can assert invalidity based on any grounds authorized under Section 282 of Title 35 of the United States Code. These grounds include, but are not limited to:

  • Lack of patentability due to being non-novel or obvious
  • Invalid specification
  • A patent claim that is overly broad

Third parties seeking to challenge patents through the PGR process must file their petitions within nine months of the date that the patent at issue is granted. The PTAB will grant a petition for review if it appears more likely than not that at least one of the claims challenged is unpatentable (or if the petition raises a novel or unsettled issue), and each party is permitted to take limited discovery relating to the factual assertions in question.

Typically, the PTAB issues decisions in post-grant review proceedings within 12 to 18 months of the date of the petition.

Inter Partes Review Proceedings

Inter partes review proceedings can be used to challenge the validity of patents, “only on a ground that could be raised under §§ 102 or 103, and only on the basis of prior art consisting of patents or printed publications.” These include challenges based on lack of novelty or non-obvious subject matter. Unlike PGR, IPR is not limited to patents issued after March 16, 2013, and challengers have until the later of nine months after the grant date or nine months after the termination of a prior PGR proceeding to file a petition for IPR.  

PGR and IPR decisions are both subject to appeal, and the lawyers in our Post-Grant Patent group also have extensive experience both challenging and defending PTAB decisions in the U.S. Court of Appeals for the Federal Circuit.

Contact the Post-Grant Patent Group at Greenblum & Bernstein

If you would like to speak with a lawyer in our Post-Grant Patent group, we encourage you to get in touch. Please contact Jill M. Browning at or Michael Fink at, or call 703-716-1191 to schedule a time to talk.