Patent Reexamination: How to Challenge Granted Patents Without Spending $1 Million

What is an ex parte (1-sided) patent reexamination request?

Suppose you have at least $1,000,000 to spend challenging a patent. With such a sizable budget, you can pursue litigation-like options such as Post Grant Review (PGR) or Inter Partes Review (IPR). But what if you don’t have $1 million dollars or even $100,000 to spend? What if your budget was less than $50,000? An ex parte reexamination request might arguably be one of the most affordable ways to challenge a patent.

Need to challenge a granted patent? Call US patent attorney Vic Lin at 949-223-9623 or email to see how we can help you request reexamination of an issued patent.

“Ex parte” means one-sided. Accordingly, the requestor does not get to participate in the patent reexamination proceedings beyond the initial stages of the process. An ex parte reexamination request requires your best arguments upfront. If the USPTO grants your request, the rest of the process is left to the Patent Office and the patent owner. You will have the option to file a reply to the Patent Owner’s Statement.

Reexamination applies only to granted patents. If you want to challenge a pending patent application, consider a patent protest or pre-issuance submission.

What are the requirements for a reexamination request?

A request for reexamination must include:

  1. a statement pointing out each substantial new question of patentability based on prior patents and printed publications;
  2. an identification of each claim being challenged, and detailed explanations of relevance of prior art applied to each claim for which reexamination is requested;
  3. a copy of every patent or printed publication relied upon, including an English translation of all necessary and pertinent parts of any patent or printed publication in a foreign language;
  4. a copy of the entire patent for which reexamination is requested;
  5. a certification that a copy of the reexamination request has been served on the patent owner (if the requestor is not the patent owner); and
  6. a certification by the third party requestor that it is not estopped from making the reexamination request (e.g., prior litigation).

Payment of the USPTO fee can be delayed.

What kinds of prior art evidence may be used to request reexamination of a patent?

Note that the eligible evidence must consist of prior patents and printed publications. In other words, only documentary evidence of prior art may be used. Other types of evidence, such as prior sales or existing products in the marketplace, will not be eligible. Find ways to produce such evidence in the form of a printed publication.

How much does 1-sided patent reexamination cost?

At our firm, the cost of a patent reexamination request starts at roughly $12,500 for the streamlined request of 40 pages or less. The cost of a non-streamlined reexamination request will start at $19,000.

Here’s a breakdown of costs:

  1. attorney’s fees starting at $9,900 for streamlined, or starting at $14,000 for non-streamlined; and
  2. USPTO small entity fees starting at $2,520 for streamlined, or $5,040 for non-streamlined.

Our attorney’s fees for a reexamination request typically start at $9,900 for a streamlined request or at $14,000 for a non-streamlined request, not including USPTO fees. Depending upon the number of claims and amount of prior art references, attorney’s fees will vary. Once we know the patent number and the number of prior art references, we can provide a flat fee estimate for a reexamination request.

How to Challenge a Patent at a Lower Cost

For a small entity, the USPTO fee will be either $2,520 for the streamlined request or $5,040 for the non-streamlined request. Large entity USPTO fees are $6,300 and $12,600, respectively.

Total reexamination costs will depend upon the size of the requestor (whether large or small entity), and the number of pages of the request. A 50% USPTO discount applies to streamlined reexamination requests which must be under 40 pages. Obviously, the number of pages in the request will be proportional to the number of claims and prior art references.

If the patent has a decent number of claims to be challenged (e.g., at least 10) and you have more than a couple of prior art references, the non-streamlined option may make more sense. Do not be penny-wise and pound-foolish. Don’t try to save a few dollars by using a shorter brief that ultimately fails to convince the USPTO to order reexamination.

What is the patent reexamination process?

Here is a brief timeline of the patent reexamination process:

  • Requestor files ex parte reexamination request and serves copy on patent owner.
  • Within 3 months of reexamination request filing date, USPTO will determine whether a substantial new question of patentability has been raised. If so, a decision ordering reexamination will be sent.
  • Within 2 months of decision ordering reexamination, patent owner may file an optional Patent Owner Statement with any narrowing claim amendments.
  • If a Patent Owner Statement is filed, requestor may file an optional reply within 2 months.
  • If no Patent Owner Statement, examiner will begin examination and issue an Office Action (e.g., 4 to 6 months from institution date).
  • Patent Owner will have an extendable 2-month deadline to respond to Office Actions.
  • Ongoing prosecution may lead to Final Office Action which may be addressed with limited options, or appealed to the PTAB or court.
  • Conclusion of reexamination proceeding leads to notice of intent to issue with examiner’s reasons for each claim found patentable.
  • USPTO issues Ex Parte Reexamination Certificate.

Can the reexamination requestor remain anonymous?

Yes, the requestor can remain anonymous by using a patent attorney to file the reexamination request.

What is the probability of a request for reexamination being granted?

According to USPTO reexamination statistics, over 92% of all ex parte reexamination requests since 1981 have been granted. That is an impressively high percentage. Approximately 23 out of 25 reexamination requests are granted.

What are your chances of success in challenging a patent?

Of all reexaminations requested by third parties, the results have been roughly:

  • 64% chance of claims changed;
  • 14% chance of all claims canceled; and
  • 20% chance of all claims confirmed.

So a granted reexamination by a third-party requestor has a roughly 79% chance of claims being changed or canceled.

One way to quantify the probability of successfully challenging a granted patent is to multiply the probability of a reexamination request (92%) by the probability of claims being changed or canceled (79%). If we multiply 92% by 79%, the result is a 73% probability of success for third party requestors.

Need to defend or request a patent reexamination?

Contact US patent attorney Vic Lin by email at or call (949) 223-9623 to see how we can develop and execute a strategy to request a patent reexamination. If your patent is being reexamined, reach out to see how we can defend your patent.

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