PTAB trial procedure
PTAB AIA trials run on a compressed and tightly choreographed schedule: petition, preliminary response, institution decision, trial, oral hearing, final written decision — all within roughly eighteen months. The procedural rules in 37 C.F.R. Part 42 govern IPR, PGR, and the now-sunset CBM proceedings, with subpart-specific rules layered on top.
The rule
An AIA trial proceeds in two distinct phases. The pre-institution phase consists of the petition, the patent owner's preliminary response, and the Director's institution decision. The post-institution phase is the trial itself: a year-long contested proceeding ending in an oral hearing and a final written decision. Three-judge panels of administrative patent judges, drawn from the Patent Trial and Appeal Board, decide both phases. Procedure throughout is governed by 37 C.F.R. Part 42, supplemented by the Office Patent Trial Practice Guide and panel-issued scheduling orders.
Statutory and regulatory source
The procedural rules sit in three layers:
- Statute. Sections 311–319 of Title 35 for IPR and §§ 321–329 for PGR fix the institution thresholds, the twelve-month decision deadline (extendable to eighteen), the right to oral hearing, and the right of appeal under § 319 (IPR) or § 329 (PGR).
- Regulation. 37 C.F.R. Part 42 implements the statute. Subpart A (§§ 42.1 through 42.80) prescribes rules common to all AIA trials — filing requirements, fees, page limits, sanctions, motion practice, oral argument. Subpart B (§§ 42.100 through 42.123) governs IPR specifically. Subpart C (§§ 42.200 through 42.224) governs PGR.
- Guidance. The Office Patent Trial Practice Guide, last comprehensively updated in November 2019 with subsequent supplements, articulates the Board's expectations on petition structure, evidence, motions, and conferences. The Guide is non-binding but routinely cited.
The framework
The petition
The petition initiates the proceeding. It must identify the petitioner, the real parties in interest, related matters, lead and back-up counsel, and the patent and claims challenged. The grounds must be presented with particularity, supported by evidence and expert declarations. 35 U.S.C. § 312(a); 37 C.F.R. § 42.104.
Word limits cap the petition: 14,000 words for an IPR petition (37 C.F.R. § 42.24(a)(1)(i)) and 18,750 words for a PGR petition (§ 42.24(a)(1)(ii)). The corresponding patent owner response and petitioner reply have their own caps. The page-based limits that originally governed petitions — 60 pages for IPR — were replaced by word-based limits in 2016 to discourage tiny-font and dense-figure abuses.
The petition must include a proposed claim construction. Since November 2018, AIA trials apply the same Phillips claim construction standard used in district court, rather than the broadest reasonable interpretation that originally applied. 37 C.F.R. § 42.100(b); § 42.200(b).
Patent owner preliminary response (POPR)
Within three months of the notice of filing date, the patent owner may file a preliminary response. 35 U.S.C. § 313; 37 C.F.R. § 42.107. Since 2016, the POPR may include testimonial evidence, with any genuine issue of material fact resolved in the petitioner's favor for purposes of institution. The POPR is the patent owner's best opportunity to defeat institution; once institution issues, the proceeding becomes far more burdensome.
Institution decision
The Board issues an institution decision within three months of the POPR or its deadline. The decision applies the statutory threshold — reasonable likelihood of prevailing on at least one claim for IPR; more likely than not for PGR — and addresses every claim and every ground in the petition under SAS Institute Inc. v. Iancu, 584 U.S. 357 (2018). Non-merits-based discretionary denial is permitted under § 314(a) and the Fintiv framework, the contours of which remain unsettled and shift across USPTO administrations.
Trial — schedule
Following institution, the panel issues a scheduling order setting due dates approximately as follows:
- Patent owner response: ~3 months after institution
- Petitioner reply: ~3 months after patent owner response
- Patent owner sur-reply: ~1 month after reply
- Oral hearing: ~9 to 10 months after institution
- Final written decision: within 12 months of institution (extendable to 18)
Discovery
PTAB discovery is sharply limited compared to district court practice. The rules distinguish two categories:
- Routine discovery. Without motion, parties must produce any exhibit cited in a paper, must serve cross-examination of declarants, and must produce information inconsistent with positions advanced. 37 C.F.R. § 42.51(b)(1).
- Additional discovery. By motion only, on a showing that the discovery is "necessary in the interest of justice." § 42.51(b)(2). The Board applies the five Garmin factors articulated in Garmin International, Inc. v. Cuozzo Speed Technologies LLC, IPR2012-00001 (P.T.A.B. Mar. 5, 2013) (informative): (1) more than a possibility and mere allegation; (2) litigation positions and underlying basis; (3) ability to generate equivalent information by other means; (4) easily understandable instructions; and (5) requests not overly burdensome to answer. The Garmin standard is demanding; additional discovery is granted sparingly.
Motions to amend
Section 316(d) and 37 C.F.R. § 42.121 permit the patent owner to move to amend the challenged claims. The motion may cancel claims or substitute a reasonable number of substitute claims, generally one for one. The substitute claims must respond to a ground of unpatentability and must not enlarge the scope of the original claims or introduce new matter.
The burden allocation for motions to amend has been litigated repeatedly. In Aqua Products, Inc. v. Matal, 872 F.3d 1290 (Fed. Cir. 2017) (en banc), the Federal Circuit held — in a fractured opinion — that the burden of persuasion on the patentability of substitute claims rests on the petitioner, not the patent owner. The Board now follows that allocation: once the patent owner satisfies the statutory and regulatory requirements for the motion, the petitioner must prove the substitute claims unpatentable by a preponderance of the evidence. The Board's pilot programs — including the Motion to Amend Pilot Program offering preliminary guidance and revised motion procedures — have evolved over time.
Oral hearing
Either party may request oral hearing under 37 C.F.R. § 42.70. Hearings typically run one to two hours per party, are usually held at PTAB facilities (Alexandria, Denver, Detroit, Dallas, San Jose) or by video, and are open to the public unless the panel grants a motion to seal portions. New evidence and new arguments are not permitted; demonstratives must be served in advance.
Final written decision
The panel issues a final written decision under 35 U.S.C. § 318(a) (IPR) or § 328(a) (PGR) addressing the patentability of every instituted claim. The decision must be issued within twelve months of institution, extendable to eighteen for good cause. § 316(a)(11); § 326(a)(11). Following the Director-review process implemented after United States v. Arthrex, Inc., 594 U.S. 1 (2021), either party may seek Director review of the final written decision; the Director may also act sua sponte.
Rehearing
A party dissatisfied with the final written decision may request rehearing under 37 C.F.R. § 42.71(d) within 30 days. Rehearing is an exceptional remedy: the moving party must specifically identify matters the Board misapprehended or overlooked. Grant rates are low.
Appeal
Either party may appeal the final written decision to the U.S. Court of Appeals for the Federal Circuit under 35 U.S.C. § 319 (IPR) or § 329 (PGR). The Federal Circuit reviews legal conclusions de novo and factual findings for substantial evidence. See standards of review. The Director's institution decision under Cuozzo Speed Technologies, LLC v. Lee, 579 U.S. 261 (2016), is generally not appealable, although the Federal Circuit retains review of constitutional questions and matters separable from the institution decision.
Burden, timing, deadlines
Burdens at PTAB are statutory:
- Institution threshold: reasonable likelihood (IPR, § 314(a)); more likely than not (PGR, § 324(a)).
- Trial-stage burden of persuasion on unpatentability: preponderance of the evidence on the petitioner. § 316(e); § 326(e).
- Trial-stage burden on amended claims: preponderance on the petitioner under Aqua Products.
The principal procedural deadlines are jurisdictional or near-jurisdictional:
- POPR: three months from notice of filing date
- Institution decision: three months from POPR
- Final written decision: twelve months from institution (extendable to eighteen)
- Rehearing request: thirty days from final written decision
- Appeal: sixty-three days under 37 C.F.R. § 90.3 (with the Federal Rules of Appellate Procedure governing thereafter)
Interaction with district court litigation
PTAB practice cannot be understood in isolation from parallel district court litigation. Three points govern the interaction:
- Stays. Defendants commonly move to stay district court litigation pending IPR. Courts apply a three-factor test: (1) whether a stay would simplify the issues; (2) the stage of the litigation; and (3) whether a stay would unduly prejudice the patent owner. The fourth factor — undue advantage to the moving party — is sometimes added. Stay grant rates vary by district. Delaware and NDCA stay liberally; EDTX and WDTX often deny.
- Discretionary denial. A trial-ready district court schedule may itself defeat institution under the Fintiv framework. The dynamics are circular: the petitioner files IPR to slow the district court, but the district court's refusal to slow itself can defeat the IPR.
- Estoppel. A final written decision triggers § 315(e) estoppel in the parallel litigation, and after California Institute of Technology v. Broadcom Ltd., 25 F.4th 976 (Fed. Cir. 2022), that estoppel is broad.
Practical notes
- The petition controls everything. Word limits, ground selection, and prior-art identification at the petition stage drive the entire trial. Late additions are usually rejected as expanding the petition's scope.
- Cross-examination by deposition is the principal evidentiary mechanism. Declarants are cross-examined by routine discovery. Objections to evidence are made by motion under 37 C.F.R. § 42.64.
- Motions to seal are common but limited. The PTAB strongly prefers public proceedings. Confidential treatment is granted on a showing of good cause.
- Conduct the call early. Parties commonly hold an initial conference call with the panel after institution to establish the schedule and resolve preliminary disputes.
- The 18-month extension is rare. The Board prides itself on hitting the twelve-month statutory target. Extension is granted only on demonstrated good cause — typically because of a § 315(c) joinder.
- Appeal standing requires Article III injury. A petitioner who is not in litigation must establish concrete injury to appeal an adverse final written decision. See standing.
Open questions
- Director review procedure. The Director-review framework implementing the Arthrex remedy is not codified by statute and continues to evolve through guidance memoranda. The standard the Director applies, the timeline for Director action, and the relationship between Director review and panel rehearing remain in development.
- Discretionary denial. The Fintiv factors and § 325(d) prior-art-overlap denial are repeatedly revised. Whether discretionary-denial guidance must be adopted through formal rulemaking — and the deference owed to such guidance — is contested.
- Motion-to-amend practice. The Board has experimented with multiple pilot programs offering preliminary guidance on substitute claims. The long-term equilibrium between speed and the patent owner's amendment opportunity is unsettled.
- The role of expert testimony in the POPR. The 2016 rule allowing testimonial evidence in the POPR — with disputes resolved in the petitioner's favor — has shifted institution dynamics. Whether the genuine-issue rule sufficiently protects patent owners in close cases continues to be debated.
- Settlement and termination. Section 317 contemplates termination by settlement, but the Board has discretion to proceed to final written decision even after settlement. The standards governing that discretion are case-specific.
See also
- Inter partes reviewThe most common AIA trial under §§ 311–319.
- Post-grant reviewBroader-grounds AIA trial under §§ 321–329.
- IPR estoppelSection 315(e) preclusion attaching at final written decision.
- DiscoveryGarmin factors govern additional discovery at PTAB.
- Federal Circuit appealsAppeal under § 319; Cuozzo limits review of institution.
- StandingArticle III injury required to appeal an adverse FWD.
- Claim constructionPhillips standard now applies at PTAB.
- Standards of reviewSubstantial evidence for facts; de novo for law.
Last reviewed: 2026