How a granted patent can be challenged at the Patent Office
A grant is not the last word, because challengers have routes at the Office and the rules for those routes are moving quickly.
Lesson 5 of 12 · 4 min
Getting a patent feels like the end of the process. It is not. In court, each claim is presumed valid, claim by claim (35 USC 282). But the Patent Office can look again at what it granted, and that presumption does not end the matter. Suspicion of granted patents is old. Justice Jackson once wrote in dissent that "the only patent that is valid is one which this Court has not been able to get its hands on" (Jungersen).
Three routes at the Office
The USPTO prices three main routes separately (USPTO fee schedule).
Inter partes review (IPR) is a trial-style challenge between the challenger and the patent owner before the Patent Trial and Appeal Board (PTAB) (PTAB trial statistics).
Post-grant review (PGR) is a similar proceeding at the same board (PTAB trial statistics).
Ex parte reexamination works differently. A requester asks the Office to take a fresh look, and the Office decides whether to order it (USPTO notice).
The gate comes first
For IPR and PGR, the first question is not whether the patent is valid. It is whether the challenge will be heard at all, a step called institution (90 FR 48335). A challenge can end at that gate with no ruling on the merits. This gate is where policy has moved fastest, so the details belong in the Current section.
How to read this area
This is the fastest-moving part of the course, so three reading habits help.
- A proposed rule is not law. It becomes a rule only when a final version is published in the Federal Register.
- A one-month rate can rest on small numbers. In our judgment, the fiscal-year figure in the PTAB statistics is the steadier one.
- Our research reached some USPTO memos only through law-firm summaries, so we name the firm when we rely on one.
What this means for you
In our judgment, the lesson is the same on both sides. Challengers need a route. Patent owners need a file that can survive one. That is one more reason for the care urged in earlier lessons: clear claims, full disclosure and restrained arguments.
Timeless wisdom
Our research found little durable authority here, and that is itself the lesson. The presumption of validity binds courts claim by claim (35 USC 282), but a grant is not the last word. Justice Jackson's dissenting quip that "the only patent that is valid is one which this Court has not been able to get its hands on" shows the suspicion is old (Jungersen). In our judgment, challengers need a route and patent owners need a file that can survive one.
What's current
As of November 5, 2026
Undiscounted request and post-institution fees are $23,750 and $28,125 for IPR and $25,000 and $34,375 for PGR. Ex parte reexamination costs $6,775 streamlined or $13,545 non-streamlined (fee schedule).
Since Oct. 20, 2025 the Director, consulting at least three PTAB judges, decides institution, one firm reports (Morgan Lewis). Another reports that "settled expectations" now counts, with patents in force about six years or more favoring denial (Fish & Richardson). FY2026 saw 500 petitions and 41% instituted by petition, against 68% in FY24 (PTAB statistics).
An October 2025 proposal would add stipulation requirements and bars to institution (90 FR 48335). It is only proposed: checks through Nov. 5, 2026 show no final rule (Federal Register).
Reexamination was 65.1% of post-grant filings in Q3 2026 (Unified Patents). For requests filed on or after April 5, 2026, patent owners may file a 30-page pre-order paper within 30 days of service (USPTO notice).
Key takeaways
- A patent can be attacked at the Office after it is granted.
- For IPR and PGR, the first fight is over whether the challenge is heard at all.
- A proposed rule is not law until a final version is published.
- A patent owner's best preparation is a file that can survive a challenge.
Check your understanding
Sources
- 35 USC 282, presumption of validity
- Jungersen v. Ostby & Barton Co., Supreme Court
- USPTO fee schedule
- PTAB trial statistics, September 2026
- USPTO notice on pre-order papers in reexamination
- 90 FR 48335, proposed PTAB rules
- Federal Register, USPTO documents
- Morgan Lewis on the PTAB's first-year reset
- Fish & Richardson on discretionary denial
- Unified Patents, Q3 2026 dispute report
The Academy is general education, not legal advice, and reading it doesn't create an attorney-client relationship. Patent law and fees change, so check the linked sources and have a registered patent attorney or agent review your situation before you file. Obsidyan sells patent software, including AI drafting tools, so weigh what these lessons say about AI tools with that in mind.