As Inter Partes Review (IPR) has become increasingly subject to discretionary denials and procedural uncertainty, Ex Parte Reexamination has reemerged as a dependable and cost-effective option for addressing patent validity. While less adversarial than IPR, reexamination is not simply a substitute. Its distinct procedural features and strategic tradeoffs can meaningfully affect litigation outcomes, claim scope, and overall portfolio value.
Building on the overview in “The Resurgence of Ex Parte Reexamination: A Strategic Alternative in 2026,” this article focuses on practical strategy. It explains how challengers and patent owners can use reexamination to manage risk, control costs, shape the record, and position cases for resolution, with particular attention to the value of early technical analysis and expert input.​

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Strategic Considerations for the Patent Challenger

For parties seeking to invalidate or narrow a competitor’s patent, Ex Parte Reexamination offers a comparatively low-risk entry point.

Anonymity. Requests for reexamination may be filed through counsel without identifying the real party in interest, allowing challengers to avoid the disclosure requirements that typically accompany IPR practice. Although anonymity is not absolute, particularly in the context of parallel litigation, it remains a meaningful procedural distinction at the administrative stage. [1] 
Cost efficiency. Reexamination fees and overall legal costs are substantially lower than IPR, making it an efficient way to test validity or apply pressure without committing to a full adversarial proceeding.
No time bar. Unlike IPR, which generally must be filed within one year of service of a complaint, a request for ex parte reexamination may be submitted at any time during the enforceable life of the patent. [2] This flexibility allows challengers to reassess strategy as litigation posture, settlement dynamics, or business priorities evolve.
Strategic Use of Technical Experts. Because reexamination is largely a paper-driven proceeding with limited opportunities for third-party participation, the quality of the initial technical presentation is often determinative. Once the USPTO finds a Substantial New Question (SNQ) of patentability and orders reexamination, the requester’s role is typically confined to the initial request and a single reply to the optional patent owner’s statement. [3] There is no opportunity for discovery, depositions, or ongoing adversarial briefing comparable to IPR.
For that reason, early involvement of technical experts can materially strengthen a requester’s position. Expert input can assist in framing the SNQ in a manner that reflects how a person of ordinary skill in the art would understand the cited references, rather than relying solely on attorney argument. This is particularly important where the challenge turns on inherency, implicit disclosures, or the technical significance of combinations that may not be explicit on the face of the prior art.
Experts can also help ensure that claim charts and mappings are technically coherent and internally consistent, reducing the risk that the Office views the request as cumulative, speculative, or merely a repackaging of arguments previously considered. Given that SNQ determinations focus on whether the prior art raises a substantial question of patentability, not whether the claims are ultimately unpatentable, clear technical framing can be decisive at the institution stage. [4] 
In practice, although expert declarations are not routinely submitted in reexamination, expert-driven analysis frequently shapes the written request itself, improving both the likelihood of institution and the overall quality of the administrative record.

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Strategic Considerations for the Patent Owner

Although often viewed as a mechanism for attack, reexamination can also serve as a valuable defensive tool for patent owners.
 

Strengthening the record. An owner may proactively seek reexamination to place newly discovered prior art before the Central Reexamination Unit, thereby reinforcing the patent’s validity and creating a more robust prosecution history before litigation arises.
Flexible claim amendments. Compared with the tightly constrained amendment practice in IPR, reexamination affords patent owners greater latitude to amend claims or introduce narrower claim sets that better distinguish the invention from the prior art. This flexibility carries tradeoffs: amendments can trigger intervening rights, limit recovery for pre-certificate activity, and narrow claim scope in ways that may weaken future enforcement or facilitate design-arounds.
Expert-guided amendment and positioning strategy. Here, too, technical experts can play a significant role. Expert analysis can help patent owners evaluate whether proposed amendments meaningfully distinguish the prior art without unnecessarily sacrificing commercial coverage. In addition, where appropriate, expert input may assist in articulating technical advantages, unexpected results, or design constraints that support patentability and inform the examiner’s understanding of the invention.
Equally important, reexamination creates prosecution history that may later be scrutinized by courts. Expert-guided explanations can help ensure that arguments made to the CRU do not inadvertently narrow claim interpretation, undermine equivalents, or create admissions that could be exploited in subsequent litigation. Below table shows strategic role of experts in the reexamination.
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