Permanent injunctions
Section 283 commits the patent injunction to the traditional principles of equity. eBay v. MercExchange dismantled the Federal Circuit's near-automatic injunction rule and required application of the four-factor equitable test in every patent case: irreparable harm, inadequate legal remedy, balance of hardships, and the public interest. The decision profoundly reshaped patent remedies, particularly for non-practicing entities.
The rule
"The several courts having jurisdiction of cases under this title may grant injunctions in accordance with the principles of equity to prevent the violation of any right secured by patent, on such terms as the court deems reasonable." 35 U.S.C. § 283. A prevailing patentee seeking a permanent injunction must demonstrate, on the traditional four-factor test, that:
- It has suffered an irreparable injury.
- Remedies available at law, such as monetary damages, are inadequate to compensate for that injury.
- Considering the balance of hardships between the plaintiff and defendant, an equitable remedy is warranted.
- The public interest would not be disserved by a permanent injunction.
eBay Inc. v. MercExchange, L.L.C., 547 U.S. 388, 391 (2006). The patentee bears the burden on each factor. No factor is presumed; the prior categorical practice of granting injunctions absent exceptional circumstances no longer applies.
Statutory and constitutional source
Section 283 has authorized injunctive relief since the Patent Act of 1952. Its language echoes the federal courts' traditional equity jurisdiction; the statute does not create a unique patent remedy but channels federal equity practice to patent cases. The Supreme Court has emphasized that "[a] major departure from the long tradition of equity practice should not be lightly implied." Weinberger v. Romero-Barcelo, 456 U.S. 305, 320 (1982). eBay applied that principle to undo the Federal Circuit's pre-2006 categorical rule. See Title 35 reference.
The constitutional source is Article I, § 8, cl. 8 — the patent right is the "exclusive Right" of the inventor — and Article III, which entrusts equitable remedies to courts within the limits of historical practice.
The framework the courts apply
Irreparable harm
Irreparable harm in a patent case typically arises from competitive injuries that cannot be measured in money: lost market share that may not be recovered, erosion of the patentee's reputation as the source of the patented technology, and loss of access to customers and ecosystems. i4i Ltd. P'ship v. Microsoft Corp., 598 F.3d 831 (Fed. Cir. 2010). Direct competition between the patentee and the infringer remains the strongest indicator of irreparable harm. Where the patentee licenses the patent broadly and does not practice it, the harm is more difficult to characterize as irreparable, although not impossible to prove.
Causal nexus
The Federal Circuit has repeatedly required a causal nexus between the patentee's harm and the infringer's use of the patented invention. The infringer's overall product success is not enough; the patentee must show that the patented features drive the harm. Apple Inc. v. Samsung Elecs. Co., 695 F.3d 1370 (Fed. Cir. 2012) (Apple I); Apple Inc. v. Samsung Elecs. Co., 735 F.3d 1352 (Fed. Cir. 2013) (Apple II) (clarifying that the patented feature need not be the sole or even principal cause of demand, but must be "some causal nexus"); Apple Inc. v. Samsung Elecs. Co., 809 F.3d 633 (Fed. Cir. 2015) (Apple IV) (rejecting a too-stringent reading of causal nexus). The post-Apple cases have refined the test toward something like a contribution showing — that the patented feature is a "driver" or "important factor" in customers' purchasing decisions.
Inadequate legal remedy
Where the harm is irreparable, money damages are by definition inadequate; the two factors travel closely together. Courts independently consider, however, whether ongoing harm is reasonably amenable to a future-royalty calculation. A patentee that has demonstrated a willingness to license to all comers at quantifiable rates may find this factor harder to satisfy. Acumed LLC v. Stryker Corp., 551 F.3d 1323 (Fed. Cir. 2009). Conversely, where the patentee has refused to license its competitors, the inadequate-legal-remedy showing strengthens.
Balance of hardships
The patentee's continuing exclusion from the market is weighed against the infringer's transition costs. Hardships incurred by the infringer that flow from the infringement itself ("self-inflicted" hardships) are given little weight. Acumed, 551 F.3d at 1330. Where an entire product line of the infringer would be enjoined, courts often craft the injunction narrowly — for example, allowing service of installed units while enjoining new sales — to balance hardships.
Public interest
The public interest factor turns on the nature of the patented technology. In life-sciences and standard-essential settings, the public-interest factor often weighs heavily. Courts have denied or narrowed injunctions on medical devices where alternatives are limited, on FRAND-encumbered standard-essential patents, and on technologies whose enjoinment would harm third parties (component suppliers, downstream customers, or interoperability). The patent system's general interest in enforcement remains a counterweight.
Practicing entity vs. NPE
eBay rejected categorical denials of injunctive relief based on the patentee's status as a non-practicing entity. 547 U.S. at 393. But the four-factor analysis is more difficult for an NPE: irreparable harm is harder to prove without market presence, and licensing patterns make legal damages presumptively adequate. Justice Kennedy's concurrence (joined by Justices Stevens, Souter, and Breyer) noted that licensing-firm plaintiffs and patents covering small components of complex products may often lack equity for an injunction. 547 U.S. at 396–97. Lower courts have followed this guidance in practice without converting it into a per se rule.
Sunset and compliance periods
Where an injunction issues against a defendant whose immediate cessation would impose disproportionate hardship on customers and the public, courts commonly include a sunset or compliance period — a defined window during which the defendant may continue limited activity (typically service of existing units, transitioning customers, or design-around) before the injunction takes full effect. The duration is set by reference to redesign feasibility and supply-chain considerations. The injunction may also include carve-outs for warranty, repair, and contractual-obligation activity.
Contempt for violation
Once issued, a permanent injunction is enforceable through contempt. The Federal Circuit replaced the prior KSM Fastening Sys., Inc. v. H.A. Jones Co. regime with the simpler approach of TiVo Inc. v. EchoStar Corp., 646 F.3d 869 (Fed. Cir. 2011) (en banc). Under TiVo, the patentee must show by clear and convincing evidence that the redesigned product is "not more than colorably different" from the enjoined product and that it infringes. The court evaluates whether changes to the previously enjoined features are significant. A defendant that obtains a good-faith opinion that its redesign avoids infringement is not safe from contempt: subjective good faith does not defeat a contempt finding, although it may mitigate sanctions.
ITC exclusion orders distinguished
Patent injunctions in district court are distinct from ITC § 337 exclusion orders. The ITC issues exclusion orders without the eBay four-factor test; the statutory standard (19 U.S.C. § 1337(d)) requires the Commission to consider four "public-interest factors" but the resemblance is structural, not doctrinal. ITC remedies are in rem (against articles entering U.S. commerce), enforced by Customs and Border Protection, and not affected by eBay. See Section 337 procedure. Many patentees pursue parallel district-court damages actions and ITC exclusion-order proceedings precisely because the remedial regimes diverge.
Burden and proof
The patentee bears the burden on each of the four factors by a preponderance of the evidence. eBay, 547 U.S. at 391. The decision to grant or deny is reviewed for abuse of discretion; underlying factual findings are reviewed for clear error; legal conclusions are reviewed de novo. Robert Bosch LLC v. Pylon Mfg. Corp., 659 F.3d 1142 (Fed. Cir. 2011).
The patentee must affirmatively prove irreparable harm; eBay rejected the older Federal Circuit presumption of irreparable harm following a finding of validity and infringement. Robert Bosch, 659 F.3d at 1149. That said, the underlying competitive facts — direct head-to-head competition, lost sales, and the significance of the patented features — frequently support the showing.
Interaction with related doctrines
Where a permanent injunction is denied, the patentee may seek an ongoing royalty for the infringer's continued use, sometimes called a "compulsory license" although the term is disfavored. Paice LLC v. Toyota Motor Corp., 504 F.3d 1293 (Fed. Cir. 2007). The ongoing royalty rate is determined by the court (not the jury) and may exceed the jury's reasonable-royalty rate to reflect the post-judgment posture, the now-adjudicated infringement, and the absence of injunctive risk.
Permanent injunctions interact with reasonable royalty and lost profits by defining the prospective component of relief. They follow from validity and infringement findings governed by claim construction, anticipation, obviousness, and written description and enablement. They are unaffected by an IPR challenge unless and until the asserted claims are held unpatentable.
Section 283 also authorizes preliminary injunctions, which require the same equitable factors as permanent injunctions, plus a likelihood of success on the merits. Preliminary injunctions in patent cases are uncommon outside the pharmaceutical and medical-device space.
Practical notes
Drafting the injunction
Federal Rule of Civil Procedure 65(d) requires injunctions to be specific, to describe in reasonable detail the acts restrained, and to bind only the parties and those in active concert with them. Broad "do not infringe" injunctions are disfavored; better practice is to identify the enjoined products by name, model number, or specification. Carve-outs and sunset provisions should be written into the order with effective dates.
Bond and stay pending appeal
A defendant ordinarily seeks a stay of the injunction pending appeal under Federal Rule of Civil Procedure 62 and Federal Rule of Appellate Procedure 8. The four-factor stay analysis (likelihood of success, irreparable injury absent stay, balance of harm, public interest) parallels the merits inquiry. The Federal Circuit has discretion to grant or deny stays.
Compliance and design-around
Defendants typically begin design-around work well before the injunction issues. Submitting the redesign to a court, sometimes through a motion for declaratory judgment of non-infringement or a motion to clarify the scope of the injunction, mitigates contempt risk. Courts vary in their willingness to "pre-clear" redesigns; some decline to issue advisory rulings.
Multi-jurisdictional considerations
U.S. patent injunctions reach U.S. acts only. Foreign manufacture and sale fall outside § 283; relief there must be obtained in the foreign jurisdiction. Where infringing components are imported, the patentee may pursue an ITC exclusion order to prevent importation.
Patterns by court
The District of Delaware and the Eastern District of Texas have produced the bulk of post-eBay injunction jurisprudence. The Western District of Texas has issued injunctions where the patentee competes directly with the defendant. The Federal Circuit reviews the orders.
Open questions
- Causal nexus standard. The Federal Circuit's Apple-Samsung sequence has refined "causal nexus" but has not produced a single, settled formulation. District courts continue to vary in how strict a connection they require between the patented feature and the patentee's harm.
- Standard-essential patents. Whether and when a patentee that has committed to FRAND licensing may obtain an injunction on a standard-essential patent is a recurring issue. The general view is that an injunction is unavailable absent a showing that the implementer is an unwilling licensee. Apple Inc. v. Motorola, Inc., 757 F.3d 1286 (Fed. Cir. 2014), overruled in part on other grounds.
- Ongoing royalty rate. Whether and how much the post-judgment royalty should exceed the jury's pre-judgment rate is decided case by case. Amado v. Microsoft Corp., 517 F.3d 1353 (Fed. Cir. 2008).
- Worldwide injunctions. District courts generally lack power to enjoin foreign acts. The remaining question is the extent to which they may enjoin domestic conduct that has predominantly foreign effect — for example, U.S. supply of components for foreign assembly under § 271(f).
See also
- Reasonable royaltyThe damages measure when an injunction is denied; basis for ongoing royalty rates.
- Lost profitsPast damages; complementary to forward-looking equitable relief.
- Willfulness and enhanced damagesOften paired with injunction motions in cases of egregious infringement.
- Exceptional case attorneys' feesSection 285 fees, frequently sought together with injunctive relief.
- eBay v. MercExchangeThe 2006 Supreme Court decision applying the traditional four-factor equitable test.
- ITC Section 337In rem exclusion-order remedy unaffected by eBay.
Last reviewed: 2026