Post Patent Grant Challenge


After you have achieved the award of a patent, you may still be subject to challenge from competitors.  You may face a post patent grant challenge.  Part of the America Invents Act or AIA the USPTO established a procedure called a Post Grant Review.  The procedure gives third parties up to 9 months after the grant of your patent to challenge the award.  The “third parties” are your competitors.  The goal of the competitor’s challenge (via a petition) is to cause the USPTO to cancel your newly allowed patent claims.  This in effect, cancels your patent. 


Although Post Grant Review may have initially been intended as a mechanism for pro se litigants to challenge competing patents of competitors, the statute has been drafted with adequately complexity to require legal support.  Note there are very limited opportunities for you to challenge a bogus patent application during the patent prosecution process.  The Post Grant Review petition was intended to provide an opportunity for a smaller market player to stop the inequitable cudgel of a bogus patent.

The Post Grant Review (PGR) is intended to be a fast process.  

The PGR proceeding is initiated by filing a petition.  The petition is filed with the USPTO.  The petition MUST be filed within 9 months of the issuance a patent.  The grounds of justification for the petition seeking the cancellation of claims are very broad.  

The petition may be based upon the patent claiming patent-ineligible subject matter.  (This can be especially disheartening to a small inventor after the inventor had just fought this battle with the examiner and the Section 101 rejections.)

Note that the post grant challenge can be based upon reasons other than prior art patents and publications.  Examples could be your prior “public” use (more than 1 year before filing the original application) or lack of enablement.  See my recent article What not to do before you file.

As indicated above, the patent can be challenged again on issues of novelty (Section 102) or obviousness (Section 103).  The challenger (competitor) can bring new prior art references different than the references cited by the examiner.  Note you or your competitor may know the prior art (past market use, etc.) better than the examiner.  The examiner’s search may have been limited to the existence of relevant patents or published patent applications.  Documented prior use may be a very big rock to throw at the newly issued patent.

If you are the owner of the new patent, note that your patent can be challenged on the basis that the specification does not adequately inform (enable) a person skilled in the art how to use or make your invention.  A person skilled in the art, or capable of hiring an industry “expert”, may spot gaps in the disclosure that the examiner glossed over.  (This is the enablement burden required even of provisional applications.)  

Another basis for challenge is that the specification does not show that the inventor/patent owner was, in reality, in possession of the invention, i.e., the inventor did not have knowledge of all the elements required of the claims.  (This is close to but distinct from the enablement requirement.  Again, there is not a “bright line” test.)  An additional basis is that the issued claims are fatally indefinite.  

Note these last two issues for challenge are less clear that possession of a “smoking gun”, i.e., documented prior use of the invention in the market.  According you (the challenger) will need to obtain skilled legal advice to evaluate the whether such a challenge exists or is feasible.


To be successful, the post patent grant challenge petition must show that the listed justifications, if not adequately rebutted by the patent owner, would show that it is more likely than not that at least ONE CLAIM IS UNPATENTABLE.  This is considered to be a higher standard than merely “a reasonably likelihood of success”.

If a petition is filed, the patent owner will be provided a copy.  The patent owner will have two months to respond.  The USPTO will have 3 months to evaluate the petition.  If the petition is deemed to have merit, the US Patent Trial and Appeals Board (PTAB) will have 12 months to decide whether one or more of the challenged claims are to be cancelled.  During the pendency of the proceeding, the patent owner will be effectively barred from bringing any infringement action.  

Note that the petitioner must meet two thresholds, i.e., first, demonstrate that the grounds stated in the petition has merit and second, provide evidence that the claims should, in fact, be cancelled.

As stated above, anyone can file a petition to challenge the new patent during the 9 month window.  This places a 9 month cloud on the validity of the patent.  

Note that the examiner plays no role in deciding the petition.  Note also that the PTAB does not conduct a trial, but rather makes its decision based upon written evidence, which can include deposition testimony, i.e., sworn answers to written or oral questions.  


The bottom line is that for 9 months after the patent issues, a competitor or other third party can challenge your patent on a broad array of issues.  One consequence of this 9 month window is that you may want to wait 9 months before asserting your patent.

This is also a valuable tool to use if your competitor (now patent owner) is likely to try to enforce a bogus patent against you (and threaten to drag you into very expensive litigation). 

©David McEwing 2020

Contact:    713-514-0137