IPR timeline: from petition to Federal Circuit appeal
An inter partes review runs on statutory deadlines. A petition must be filed within one year after the petitioner is served with an infringement complaint. The patent owner has three months to file a preliminary response; the PTAB decides whether to institute within three months after that; and a final written decision is due within one year of institution, extendable by up to six months for good cause. Counting from the petition, a typical IPR reaches a final written decision in about eighteen months, and a Federal Circuit appeal can add a year or more.
Before filing: who may petition and when
- Who: any person other than the patent owner. 35 U.S.C. § 311(a). The petition must identify all real parties in interest. § 312(a)(2).
- Earliest filing: for patents subject to the AIA's first-inventor-to-file provisions, a petition may not be filed until nine months after grant, or until any instituted post-grant review is terminated. § 311(c). During that first nine months, a challenger may instead file a post-grant review petition.
- Declaratory judgment bar: IPR may not be instituted if, before filing the petition, the petitioner filed a civil action challenging the validity of a claim of the patent. A counterclaim of invalidity does not count. § 315(a)(1), (3).
- One-year time bar: IPR may not be instituted if the petition is filed more than one year after the petitioner, its real party in interest, or a privy was served with a complaint alleging infringement of the patent. § 315(b). The bar does not apply to a request for joinder under § 315(c). The Supreme Court held in Thryv, Inc. v. Click-to-Call Technologies, LP, 590 U.S. 45 (2020), that the PTAB's application of § 315(b) is part of the institution decision and is not appealable.
Only grounds under §§ 102 and 103, and only on the basis of prior art consisting of patents or printed publications, may be raised. § 311(b). See inter partes review.
Petition to institution (about six months)
- Petition filed; filing date accorded. The PTAB issues a notice according a filing date once the petition is complete.
- Patent owner preliminary response — three months. The patent owner may file a preliminary response within three months of the notice of filing date. 37 C.F.R. § 42.107(b). The Board may authorize a short petitioner reply and patent owner sur-reply on specific issues.
- Institution decision — three months after the preliminary response. The Director must decide whether to institute within three months after the preliminary response is filed or the last date on which it could have been filed. 35 U.S.C. § 314(b). The merits threshold is a reasonable likelihood that the petitioner would prevail on at least one challenged claim. § 314(a). Under SAS Institute Inc. v. Iancu, 584 U.S. 357 (2018), an instituted review must address every claim the petition challenges, and USPTO practice also institutes on all grounds.
Discretionary denial. The Director may deny institution even when the merits threshold is met. USPTO practice on discretionary denial — including the weight given to parallel district court or ITC proceedings — changed repeatedly in 2025, when discretionary issues began to be briefed separately and decided at the Director level and the Director announced that he would personally decide institution. Check current USPTO guidance for the procedure in force.
No appeal of institution. The decision whether to institute is "final and nonappealable." § 314(d); Cuozzo Speed Technologies, LLC v. Lee, 579 U.S. 261 (2016). A party may request rehearing: within fourteen days of a decision to institute, or within thirty days of a decision denying institution. 37 C.F.R. § 42.71(d).
Trial (twelve months from institution)
After institution, the Board issues a scheduling order. A representative sequence runs:
- patent owner response and any motion to amend — about three months after institution;
- petitioner reply and opposition to any motion to amend — about three months later;
- patent owner sur-reply and further motion-to-amend briefing — about one to two months later;
- oral hearing — roughly nine months after institution;
- final written decision — within one year of institution. 35 U.S.C. § 316(a)(11).
The one-year deadline may be extended by up to six months for good cause, and may be adjusted in cases of joinder. § 316(a)(11). Extensions are uncommon. Discovery is limited to routine discovery, depositions of declarants, and additional discovery in the interests of justice. See PTAB trial procedure.
Settlement can end the proceeding as to the settling petitioner, and the Board may terminate the trial or proceed to a final decision. § 317(a).
After the final written decision
- Rehearing or Director Review. A party may request rehearing by the panel within thirty days of the final written decision, 37 C.F.R. § 42.71(d)(2), or request review by the USPTO Director under the Director Review process adopted after United States v. Arthrex, Inc., 594 U.S. 1 (2021). Check current USPTO procedures for the Director Review deadline and format.
- Estoppel attaches. Once a final written decision issues on a claim, the petitioner (and its real party in interest or privy) is estopped from asserting that the claim is invalid on any ground it raised or reasonably could have raised in the IPR, in later USPTO proceedings, district court, and the ITC. § 315(e). See IPR estoppel.
- Appeal to the Federal Circuit — sixty-three days. A party dissatisfied with the final written decision may appeal to the Federal Circuit. 35 U.S.C. §§ 141(c), 319. The notice of appeal is due sixty-three days after the final decision, or after a decision on a timely rehearing or Director Review request. 37 C.F.R. § 90.3. A petitioner that lost must show Article III standing to appeal; the patent owner whose claims were cancelled has standing. See Federal Circuit appeals.
- The IPR certificate. When the time for appeal has expired or any appeal has terminated, the Director issues and publishes a certificate canceling any claim found unpatentable, confirming any claim found patentable, and incorporating any new or amended claim into the patent. § 318(b). Amended or new claims are subject to intervening rights in favor of those who made, used, or acquired the product before the certificate. § 318(c).
Timeline at a glance
- Day 0: petition filed (no later than one year after service of an infringement complaint).
- About 3 months: patent owner preliminary response.
- About 6 months: institution decision.
- About 9 months: patent owner response (three months after institution).
- About 15 months: oral hearing.
- About 18 months: final written decision (twelve months after institution).
- Plus 63 days: deadline for notice of appeal.
- After appeal: IPR certificate issues.
In parallel district court litigation, a defendant typically files its petition within months of being sued and asks the court to stay the case pending IPR. Whether a stay is granted varies by district and by the stage of the case. See courts.
Frequently asked questions
How long does an inter partes review take?
About eighteen months from petition to final written decision: roughly three months for the preliminary response, three months to institution, and twelve months from institution to decision. An appeal to the Federal Circuit adds more time.
What is the IPR one-year time bar?
Under 35 U.S.C. § 315(b), an IPR may not be instituted if the petition is filed more than one year after the petitioner, its real party in interest, or a privy was served with a complaint alleging infringement of the patent, except for joinder requests.
Can you appeal a decision denying institution of an IPR?
No. Institution decisions are final and nonappealable under § 314(d) (Cuozzo, 2016; Thryv, 2020). A party may request rehearing by the Board within the deadlines in 37 C.F.R. § 42.71(d).
What is an inter partes review certificate?
After appeals are exhausted, the USPTO Director issues a certificate under 35 U.S.C. § 318(b) canceling claims found unpatentable, confirming claims found patentable, and adding any amended or new claims to the patent.
What happens to my patent if a third party files an IPR?
The patent remains in force while the IPR is pending. If the PTAB institutes review and finds claims unpatentable, those claims are canceled by certificate after any appeal. Parallel infringement litigation may be stayed in the meantime.
See also
- Inter partes reviewGrounds, standards, and strategy.
- PTAB trial procedurePart 42 rules, discovery, and motions to amend.
- IPR estoppelWhat a petitioner cannot argue after a final decision.
- Post-grant reviewThe nine-month window for broader challenges.
- Federal Circuit appealsAppeals from PTAB decisions.
- Which court hears patent casesHow the PTAB fits with the courts.
Last reviewed: October 2026