Proceedings guide
Inter Partes Reexamination (Historical)
Inter partes reexamination was an optional USPTO procedure, created in 1999, in which a third-party requester could participate throughout the reexamination. The America Invents Act replaced it with inter partes review on September 16, 2012. New requests can no longer be filed; this page explains the history for readers meeting it in older decisions.
Key Facts
- Status
- Closed to new requests
- Ended
- September 16, 2012
- Replaced by
- Inter partes review
- Created
- 1999 (American Inventors Protection Act)
On this page
What it was
Optional inter partes reexamination let a third-party requester take part in the proceeding: the requester could comment on each patent owner response and appeal adverse determinations. It applied to patents issued from applications filed on or after November 29, 1999, and was limited to patents and printed publications.
What happened to it
The America Invents Act (2011) replaced inter partes reexamination with inter partes review, effective September 16, 2012. Requests filed before that date continued under the old rules; no new requests are accepted.
Why you still see it
Decisions, treatises and older articles discuss it, and some cases involving reexamination estoppel turn on it. When you meet the term, the modern counterparts are:
- For a trial-like challenge with an active requester: inter partes review or post-grant review.
- For a lower-cost, limited-participation challenge: ex parte reexamination.
The comparison chart shows the current options side by side.
Primary Sources
Related Pages
- Proceedings guideInter Partes Review (IPR)Inter partes review is a trial before the Patent Trial and Appeal Board in which anyone other than the patent…
- Proceedings guideEx Parte ReexaminationEx parte reexamination lets anyone, including the patent owner, ask the USPTO to re-examine an issued patent…
- GuidePost-Grant Proceedings Comparison ChartUse this chart to compare the USPTO's post-grant proceedings: who can use each proceeding, when it is…
Educational information; not legal advice. Statutes, rules and USPTO practice change. Confirm against the primary sources and consult a registered patent practitioner before acting. Disclaimer.