Standing in patent cases
Standing in a patent case is two questions: whether the plaintiff is a "patentee" entitled to sue under 35 U.S.C. § 281, and, in declaratory judgment actions, whether there is an Article III case or controversy. The first question turns on title and the substantial rights conveyed by any assignment or license. The second turns on the totality of circumstances under MedImmune.
The rule
Only a "patentee" may bring a civil action for patent infringement. 35 U.S.C. § 281. The Patent Act defines patentee to include "the patentee to whom the patent was issued" and "successors in title." 35 U.S.C. § 100(d). To sue alone, a plaintiff must hold either legal title to the patent or "all substantial rights" — so much of the bundle that the transfer is the equivalent of an assignment. A plaintiff who holds less than all substantial rights — typically an exclusive licensee — has prudential standing only and must join the patentee. A bare licensee with no exclusive rights cannot sue at all.
The Federal Circuit recharacterized parts of patent standing as a statutory rather than jurisdictional question in Lone Star Silicon Innovations LLC v. Nanya Technology Corp., 925 F.3d 1225 (Fed. Cir. 2019). The court held that whether a plaintiff falls within the § 281 class of "patentees" is a statutory cause-of-action question, not Article III standing. The distinction matters because statutory standing defects can be cured by joinder, while Article III defects cannot.
Governing statute
- 35 U.S.C. § 281 ("A patentee shall have remedy by civil action for infringement of his patent.") — the source of the right to sue.
- 35 U.S.C. § 100(d) — definition of "patentee" to include successors in title.
- 35 U.S.C. § 154(a) — the bundle of exclusive rights granted by a patent.
- 35 U.S.C. § 261 — patents have the attributes of personal property and may be assigned in writing; recording rules.
- 35 U.S.C. § 262 — co-owners may make, use, or sell the invention without the consent of and without accounting to the others.
- 28 U.S.C. § 2201 (Declaratory Judgment Act) — supplies the jurisdictional vehicle for declaratory actions, but does not enlarge Article III.
- Article III, § 2 — case-or-controversy requirement for federal jurisdiction generally and for DJ actions specifically.
The framework: title, substantial rights, joinder
Patentee standing
A plaintiff holds patentee standing where (1) the patent issued to that plaintiff, (2) the plaintiff holds legal title by recorded assignment, or (3) the plaintiff holds "all substantial rights" under the patent through an agreement with the title holder. Where the plaintiff holds all substantial rights, the agreement is treated as an assignment in fact, regardless of label. Vaupel Textilmaschinen KG v. Meccanica Euro Italia S.P.A., 944 F.2d 870 (Fed. Cir. 1991).
The "all substantial rights" inquiry is comprehensive. Federal Circuit case law identifies a non-exhaustive list of factors:
- The right to make, use, and sell the invention.
- The right to sue and to control litigation and settlement.
- The right to grant licenses and sublicenses.
- The right to enforce the patent against infringers.
- The duration of the rights conveyed.
- The nature and scope of any reversionary or termination rights.
- The right to receive royalties and to direct the commercial exploitation of the invention.
Where a transferor retains a meaningful right — say, a veto over enforcement decisions or an exclusive field of use that the transferee may not invade — the transferee has not received all substantial rights. Alfred E. Mann Foundation for Scientific Research v. Cochlear Corp., 604 F.3d 1354 (Fed. Cir. 2010); Lone Star, 925 F.3d at 1230.
Exclusive licensee standing
An exclusive licensee — one who has the exclusive right to make, use, or sell within a defined field — has standing to sue but must join the patentee unless the license conveys all substantial rights. Independent Wireless Telegraph Co. v. Radio Corp. of America, 269 U.S. 459 (1926); Aspex Eyewear, Inc. v. Miracle Optics, Inc., 434 F.3d 1336 (Fed. Cir. 2006). A licensee that the patentee refuses to join can compel joinder by suing the patentee as an involuntary plaintiff. Independent Wireless, 269 U.S. at 469–70.
Bare licensee — no standing
A non-exclusive licensee has no constitutional injury from infringement and cannot sue, even with the patentee's consent. Ortho Pharmaceutical Corp. v. Genetics Institute, Inc., 52 F.3d 1026 (Fed. Cir. 1995).
Co-owners and joinder
Each co-owner of a patent has the right to sue for infringement only with the joinder of every other co-owner. Israel Bio-Engineering Project v. Amgen, Inc., 475 F.3d 1256 (Fed. Cir. 2007); Ethicon, Inc. v. United States Surgical Corp., 135 F.3d 1456 (Fed. Cir. 1998). A co-owner can refuse to join and thereby defeat the suit. The rule reflects 35 U.S.C. § 262, which gives each co-owner an independent right to use the patent without accounting. There is no general rule allowing a non-consenting co-owner to be made an involuntary plaintiff in patent infringement, although the Federal Circuit recognized a narrow exception in Independent Wireless-type situations where the co-owner is contractually obligated to join.
Standing for declaratory judgment
Article III standing for a declaratory judgment of noninfringement or invalidity requires a definite and concrete controversy. The Supreme Court rejected the prior "reasonable apprehension of suit" test in MedImmune, Inc. v. Genentech, Inc., 549 U.S. 118 (2007), and replaced it with a "totality of the circumstances" inquiry: whether the facts alleged "show that there is a substantial controversy, between parties having adverse legal interests, of sufficient immediacy and reality to warrant the issuance of a declaratory judgment." 549 U.S. at 127. After MedImmune, demand letters and licensing communications can support DJ jurisdiction even without an explicit threat to sue, depending on context.
The Lone Star reframing
Lone Star distinguished between Article III standing — which requires injury, causation, and redressability — and statutory standing under § 281, which asks whether the plaintiff is the proper party to sue. The court held that the absence of all substantial rights is a § 281 problem and is curable by joinder rather than dismissal. The decision smoothed many earlier disputes in which lack of "standing" was treated as a jurisdictional defect that could be raised at any time.
Burden, timing, and key deadlines
The plaintiff bears the burden of establishing standing. The burden runs through every stage of the case, but it is particularly acute at three points:
- Pleading. The complaint must allege ownership of the patent and the basis for the plaintiff's right to sue. Many courts require attachment of the relevant assignments.
- Rule 12(b) motion. Defendants typically raise standing in the first responsive pleading, sometimes by motion to dismiss for lack of subject-matter jurisdiction (Rule 12(b)(1)) or for failure to state a claim (Rule 12(b)(6)). Under Lone Star, a § 281 defect is generally a Rule 12(b)(6) issue, while Article III defects are Rule 12(b)(1) issues.
- Summary judgment. Where ownership history is complex, a Rule 56 motion attacking standing forces the patentee to produce all assignments, employment agreements, and corporate transactions affecting title.
Standing must exist at the time the complaint is filed; later transfer cannot retroactively cure a defect. Schreiber Foods, Inc. v. Beatrice Cheese, Inc., 402 F.3d 1198 (Fed. Cir. 2005). However, joinder of an absent patentee is permitted at any time and reaches back to the filing date of the original complaint.
Interaction with related procedural mechanisms
Assignment recording
35 U.S.C. § 261 requires assignments to be in writing and provides that an unrecorded assignment is void against a subsequent bona fide purchaser without notice if the assignment is not recorded within three months of execution or before the later transfer. Recording protects priority but is not a prerequisite to standing.
Inventor assignment and employment agreements
An inventor's assignment to an employer must be effective. The Federal Circuit distinguished between "I will assign" (a promise to assign in the future) and "I hereby assign" (a present transfer of future rights) in FilmTec Corp. v. Allied-Signal Inc., 939 F.2d 1568 (Fed. Cir. 1991). The Supreme Court applied that distinction in Board of Trustees of the Leland Stanford Junior University v. Roche Molecular Systems, Inc., 563 U.S. 776 (2011), holding that a present assignment to a third party trumped a later "agree to assign" obligation to the employer.
Bayh-Dole
Patents arising from federally funded research are subject to the Bayh-Dole Act, 35 U.S.C. §§ 200–212, which gives contractor universities and small businesses the option to retain title. Standing in such cases turns on whether the contractor properly elected to retain title and on the chain of transfers from the contractor.
Bankruptcy
A patent owned by a debtor becomes property of the bankruptcy estate. Suit cannot be maintained without authorization from the trustee or, in Chapter 11, the debtor in possession. Failure to schedule a patent claim in bankruptcy may estop a later suit.
Corporate transactions
Mergers and acquisitions raise standing questions when the patent transfer is by operation of state law (often automatic in mergers) versus by separate assignment (required in asset sales). Counsel should confirm — and document — the path of title in any portfolio acquired through M&A.
Reverse payment and licensing structures
Hatch-Waxman and biosimilar litigation often involve license-back arrangements that pinch the "all substantial rights" inquiry. Courts scrutinize the surviving rights of the licensor closely.
Practical notes
Document the chain of title
Before filing, gather the issuance records, every assignment, every license, every change-of-name filing, every corporate restructuring document. Defendants will demand these, and a clean record forecloses many standing arguments.
Match the prayer for relief to the rights conveyed
If the plaintiff does not hold the right to seek injunctive relief — for example, where a license-back gives the assignor a right to operate — the complaint should not seek an injunction barring the assignor's activity. Mismatched relief invites dismissal.
Read the license carefully
The label "exclusive license" is not dispositive; courts look at substance. Reservations of rights, field-of-use limitations, sublicensing constraints, and reversionary triggers all factor into the all-substantial-rights analysis.
Decide on joinder early
If the patentee will be joined, do so up front. Late-stage joinder under Lone Star is available but invites motion practice and may force a continuance.
Plan for DJ standing
Counsel for accused infringers contemplating a DJ action should preserve the demand letters, licensing communications, and any patentee statements that establish a substantial controversy under MedImmune.
Track inventorship
Inventorship affects ownership. An omitted joint inventor — who has not assigned — owns an undivided share, and any subsequent infringement plaintiff must join that inventor. Inventorship can be corrected under 35 U.S.C. § 256, but the relief is prospective.
Pressure points
Lone Star's effect on prior precedent
The full reach of Lone Star remains to be worked out. Many earlier Federal Circuit cases used "standing" language for what we now call statutory standing. The labels matter for waiver, raising defects on appeal, and the timing of joinder.
Standing in IPR vs. district court
Article III standing is required to appeal an IPR decision to the Federal Circuit, but is not required to file the IPR petition. The Federal Circuit confirmed in Consumer Watchdog v. Wisconsin Alumni Research Foundation, 753 F.3d 1258 (Fed. Cir. 2014), and Phigenix, Inc. v. Immunex Corp., 845 F.3d 1168 (Fed. Cir. 2017), that an IPR petitioner must show concrete injury to appeal. See inter partes review.
"Substantially all rights" as a moving target
The factor list is non-exhaustive, and the weight of any single factor varies with the others. Securitization and patent assertion entity transactions continue to test the limits.
Sovereign immunity
State universities frequently assert Eleventh Amendment immunity in PTAB and ITC proceedings while owning patents asserted in district court. The intersection of immunity and standing remains active.
Reverse standing and DJ piercing
Some accused infringers structure DJ actions to invoke the patentee even where the formal title holder is an affiliate. Courts have varied on whether the "patentee" can be reached through corporate veil arguments.
See also
- Title 35The full Patent Act, including § 281, § 261, and § 262.
- Patent venueVenue and standing are independent threshold questions.
- Patent discoveryDiscovery into ownership, assignments, and licensing.
- Markman hearingsThe claim construction process that follows the standing inquiry.
- Permanent injunctionsInjunctive relief is unavailable to a plaintiff that lacks all substantial rights.
- Reasonable royaltyDamages standing tracks the patent rights actually held.
- Lost profitsLost-profits standing requires that the plaintiff itself sells the patented product.
- Inter partes reviewStanding rules differ between PTAB petitions and Federal Circuit appeals.
- Federal Circuit appealsArticle III standing is required for appellate jurisdiction.
- GlossaryDefinitions of patentee, exclusive licensee, and assignment.
Last reviewed: 2026