On August 4, 2026, the U.S. Court of Appeals for the Federal Circuit issued a precedential opinion holding that there is no presumption of irreparable harm on preliminary injunction motions in patent cases. The decision marks a significant recalibration of the evidentiary framework governing early-stage injunctive relief and will require patent litigants on both sides of the caption to reassess how they build, and defend against, motions seeking to halt allegedly infringing conduct before trial.
The ruling arose from an appeal of a district court order granting a preliminary injunction in litigation involving electrical wall outlet covers. Although the underlying dispute concerned a comparatively narrow product category, the Federal Circuit used the case as a vehicle to clarify the standard applicable across all patent preliminary injunction motions. Going forward, patent owners can no longer rely on any presumption that irreparable harm follows from a strong showing of likely infringement and validity. Instead, they must come forward with concrete, case-specific evidence demonstrating that money damages will be inadequate and that harm during the pendency of the litigation cannot be remedied through post-judgment relief.
The practical consequences of this shift are substantial. Patentees seeking preliminary injunctions will need to invest earlier and more heavily in the record supporting irreparable harm, including evidence of price erosion, loss of market share, damage to goodwill or reputation, and the nexus between the patented feature and any competitive injury. Accused infringers, by contrast, gain a more meaningful opportunity to defeat preliminary relief on the harm prong alone, even where the merits analysis may favor the patentee. Careful attention to declarations, expert support, and contemporaneous business records will be essential on both sides.
Clients with pending preliminary injunction motions, or those contemplating such motions in the near term, should review their evidentiary submissions and litigation strategy in light of the heightened standard. Parties currently facing motions should likewise evaluate whether the record before the court satisfies the clarified requirements. The decision may also influence broader considerations about timing, venue, and the sequencing of related proceedings such as inter partes review.
This alert is intended for general informational purposes only and does not constitute legal advice. Clients should consult counsel for guidance tailored to their specific circumstances.