Venues for Expert Witnesses: Patent Trial and Appeal Board  

By Noah Bolmer

Established to provide a specialized forum within the U.S. Patent and Trademark Office (USPTO), the Patent Trial and Appeal Board (PTAB) has become a central stage for challenges to the validity of issued patents. For expert witnesses, the PTAB represents a distinctive environment: testimony is critical in how complex technologies are interpreted, yet expectations differ markedly from those in Federal courts. The PTAB places experts in a setting where their contributions help determine the fate of intellectual property at the core of innovation and commerce.  The PTAB is focused on unpatentability by a preponderance of the evidence, while Federal Courts must prove invalidity by clear and convincing evidence.  

Recent changes to institution policies—particularly the use of discretionary denials and the “settled expectations” doctrine—have added controversy to this framework, reshaping how and when patents can be challenged and drawing scrutiny from industry and the courts. 

Background  

Before the creation of the Patent Trial and Appeal Board, expert testimony in intellectual property disputes was largely confined to federal courts.  

Patent litigation often required scientists, engineers, and industry specialists to explain technical concepts to judges, and juries, particularly in cases involving complex technologies. Experts were central to questions of infringement and validity, but the process was lengthy and costly, with full trials demanding extensive live depositions and court testimony. The absence of a streamlined forum meant that challenges to patent quality could take years to resolve, burdening both courts and litigants with significant costs and delayed protection. 

The America Invents Act of 2011 established the PTAB to address these concerns. Congress sought a specialized venue within the USPTO that could handle validity challenges more efficiently than district courts. By creating procedures such as inter partes review and post‑grantreview, the Act gave parties a way to contest patents through a faster, more technical process overseen by administrative judges with extensive patent expertise. Expert witnesses were built into this model from the start; their declarations and depositions became the primary means of translating scientific detail into a record that could guide the Board’s decisions. 

The PTAB has grown into a major  forum for patent disputes, handling thousands of cases each year, with expert testimony shaping outcomes in industries ranging from pharmaceuticals to software. Today, experts before the PTAB are expected not only to clarify technical issues but also to provide the analytical foundation for decisions that reverberate across the IP ecosystem.   

Procedure  

Cases at the PTAB typically begin with a petition for inter partes review (IPR). In an IPR, a party asks the Board to re‑examine specific patent claims in light of prior art. If the Board finds a reasonable likelihood that at least one claim is invalid, it institutes the review and sets a strict schedule, usually requiring a final written decision within twelve months.  

Once instituted, the process turns on written submissions and evidence. Expert witnesses provide declarations—formal statements supported by exhibits—that explain how prior art relates to the challenged claims. These declarations are then tested in depositions, where opposing counsel questions the expert under oath. The transcripts are submitted into the record, serving as the PTAB equivalent of courtroom cross‑examination. Oral hearings, when they occur, are short and focused on attorney argument; experts themselves rarely appear.  

Key procedural elements include:  

• Petition and institution decision. The Board determines whether the case should move forward.  

• Expert declarations. Written statements present technical opinions and supporting data.  

• Depositions. Experts are examined under oath, with transcripts forming part of the record.  

• Panel review. Administrative patent judges evaluate the record directly.  

• Oral argument. Hearings are brief and attorney‑driven.  

Evidentiary Standards  

The PTAB applies its evidentiary framework under 37 C.F.R. Part 42. Expert declarations are governed by USPTO rules, and those declarations stand as the testimony itself. This contrasts with district court practice, where FRCP Rule 26 requires expert reports that anticipate live testimony, and admissibility is tested under FRE Rule 702. Instead, adversarial testing occurs through depositions conducted under its own procedures, with transcripts submitted into the record for consideration by the Board.  

The Board admits evidence unless deemed irrelevant, immaterial, or unduly prejudicial, reflecting a broader admissibility standard than the under FRE rules. The result is a system where the durability of expert contributions depends on the clarity and consistency of the written record. Declarations and deposition transcripts define the evidentiary landscape, shaping how technical expertise influences the Board’s decisions.  

Public Record  

Proceedings before the Patent Trial and Appeal Board are conducted on a public docket. Petitions, institution decisions, expert declarations, deposition transcripts, and final written decisions are filed electronically and accessible through the USPTO’s PTAB system. Unless a party successfully moves to seal specific confidential information, the filings remain open to public inspection.  

Each decision contributes to a growing archive of how administrative patent judges interpret prior art, weigh expert testimony, and apply statutory standards. For practitioners, the availability of declarations and transcripts provides insight into how experts frame technical arguments and withstand adversarial testing. For companies, the public nature of the record means that challenges to patents—and the technical reasoning behind them—are visible to competitors and investors alike. The PTAB’s transparency reinforces its role as both a dispute‑resolution dispute resolution forum and a source of guidance for future cases. The visibility of expert input, in particular, underscores how technical testimony shapes not only individual outcomes but the broader development of patent law.  

Appeal and Review  

Final written decisions of the Patent Trial and Appeal Board are subject to direct appeal to the United States Court of Appeals for the Federal Circuit, which reviews the Board’s findings for legal correctness and evidentiary sufficiency, applying standards of review that distinguish between questions of law, which are considered de novo (afresh), and factual determinations, which are upheld unless unsupported by substantial evidence. This appellate pathway gives PTAB decisions a dual character: they are binding on the parties in the immediate dispute, but they also feed into a broader jurisprudence once scrutinized by the Federal Circuit.  

The Board’s own rulings may be designated as precedential or informative for future PTAB panels, but they do not carry stare decisis effect in district courts. Instead, it is the Federal Circuit’s opinions that establish binding precedent across venues. In practice, this means that the durability of expert testimony and the weight of technical arguments at the PTAB are ultimately tested not only by adversarial deposition but by appellate review, where the clarity of the written record and the rigor of the Board’s reasoning determine whether the outcome stands.  

Policy Changes 

Recent reforms to institution decisions at the PTAB have become one of the most contested developments in patent practice. Under current USPTO leadership, the Board has expanded the use of discretionary denials, most notably through the “settled expectations” policy that makes it more difficult to challenge patents that have been in force for more than six years. This approach has lowered institution rates significantly, dropping from historic levels of 65–68% to around 42% in early 2026, and has altered the strategic calculus for companies that once relied on inter partes review as a primary defense against questionable patents. 

The reforms extend beyond settled expectations. Decision making has been centralized, with the Director personally reviewing institution determinations. New factors such as domestic manufacturing have been introduced, requiring the Board to consider whether the petitioner or patent owner manufactures in the United States. Restrictions on serial challenges have also been implemented to limit inter partes review for claims previously upheld in court or subject to parallel litigation. Together, these changes have reshaped the PTAB’s role, making it more difficult for companies—particularly in the technology sector—to challenge patents, while supporters argue that the reforms strengthen patent reliability and protect domestic industry. 

Critics contend that the policies insulate older patents from review and fuel litigation, a controversy that has already reached the courts. Google and other companies have petitioned the Supreme Court to strike down the settled expectations policy as unlawful, arguing that it shields patents from scrutiny and undermines the statutory framework for review. For expert witnesses, the practical impact is with fewer instituted reviews, there may be fewer opportunities to present technical testimony. 

Conclusion  

The Patent Trial and Appeal Board has reshaped the role of experts in patent disputes. Its procedures compress cases into a twelve‑month schedule, its evidentiary rules center on declarations and depositions, and its public docket ensures that technical arguments are visible well beyond the immediate parties. Expert input is tested in writing, scrutinized by administrative judges, and subject to appellate review at the Federal Circuit. The combination of speed, transparency, and oversight defines the PTAB as a forum where technical expertise is decisive and the written record carries enduring weight. 

If you’d like to be considered for expert witness opportunities, join Round Table Group. For over 30 years, we’ve connected litigators with the most qualified experts across disciplines. Call us at 202‑908‑4500 or sign up today to learn more.