Of 8,927 ex parte reexaminations requested by third parties that ended in a certificate, through September 2025, 61.0% changed the claims. 22.9% confirmed every claim, and 16.1% canceled every claim.
Before you read
When a third-party ex parte reexamination ends in a certificate, what is the most common result?
Claims changed, in 61.0% of 8,927 certificates. Every claim was confirmed in 22.9% and canceled in 16.1%.
Part 1 of 4
A reexamination ends with a certificate that confirms, cancels or changes the claims. The USPTO has tallied every one since the procedure began in 1981.
8,927 certificates, all years through Sept 30, 2025
Tap a segment to read what it covers.
Source
Part 2 of 4
The tempting reading
61% of challenged patents lose in reexamination.
What the category means
“Claims changed” counts certificates with amended or newly added claims. An owner can narrow a claim and keep a valuable patent. Only the 16.1% that canceled every claim are outright losses of the whole patent.
Owners who request their own reexamination see a similar pattern: of 4,025 certificates, 68.4% changed the claims, 21.3% confirmed them all and 10.3% canceled them all.
Part 3 of 4
Overall pendency from filing date to certificate, as of September 30, 2025. A few long cases pull the average above the median.
Source
Part 4 of 4
The takeaway
A reexam rarely leaves the claims exactly as they were. Plan for amendment, on either side.
Precedential decisions bind the Board within their designated scope. Informative decisions show the Office’s reasoning but do not bind the Board. Court opinions are cited for what they decided; later history was checked on the date shown above.