The Federal Circuit has jurisdiction over appeals from a final decision of a district court “in any civil action arising under, . . . any Act of Congress relating to patents.” 28 U.S.C. § 1295(a)(1). Under “the ‘well-pleaded complaint rule,'” jurisdiction depends on “the face of the plaintiff's properly pleaded complaint.” Caterpillar Inc. v. Williams, 482 U.S. 386, 392 (1987). 

An action can “aris[e] under” federal patent law in two ways: if “a well-pleaded complaint establishes . . . that federal patent law creates the cause of action,” or if “the plaintiff's right to relief necessarily depends on resolution of a substantial question of federal patent law, in that patent law is a necessary element of one of the well-pleaded claims.” Christianson v. Colt Industries Operating Corp., 486 U.S. 800, 808–09 (1988); see also Xitronix Corp. v. KLATencor Corp., 882 F.3d 1075, 1076 (Fed. Cir. 2018).

Situations falling within the “‘special and small'” second category—that is, where the plaintiff's right to relief necessarily depends on resolution of a substantial question of patent law, an exception to the general requirement that the relevant federal law create the cause of action—are “extremely rare.” Gunn v. Minton, 568 U.S. 251, 257–58 (2013) (quoting Empire Healthchoice Assurance, Inc. v. McVeigh, 547 U.S. 677, 699 (2006)). 

To come within that second category, it had to involve a federal issue that was “(1) necessarily raised, (2) actually disputed, (3) substantial, and (4) capable of resolution in federal court without disrupting the federal-state balance approved by Congress.” Gunn, 568 U.S. at 258; see also Vermont v. MPHJ Technology Investments, LLC, 803 F.3d 635, 645 (Fed. Cir. 2015); NeuroRepair, Inc. v. The Nath Law Group, 781 F.3d 1340, 1344 (Fed. Cir. 2015). In addition, the question of whether an issue of federal law is one that must be decided in the case is “substantial in the relevant sense,” which is an inquiry focused on “the importance of the issue to the federal system as a whole.” Gunn, 568 U.S. at 260; cf. Friedler v. Stifel, Nicolaus, & Co., 108 F.4th 241, 246–47 (4th Cir. 2024) (addressing arbitral-award review involving federal securities law). 

In Acorda Therapeutics, Inc. v. Alkermes PLC, No. 2023-2374, __ F.4th __ (Fed. Cir. July 25, 2025), Acordia sought to modify an arbitral award on the ground that the arbitration panel manifestly disregarded the law. But the Federal Circuit held that it lacked jursidiction because the right to relief did not necessarily depend on resolution of a substantial question of patent law. The only aspect of the modification request for which Acorda sought a judicial determination was the assertion of error in denying the remedy of recoupment of past royalties paid. Acorda, however, had presented two alternative grounds as establishing manifest error, only one of which rested on patent law (namely, that when a patent expires, royalty provisions became unenforceable). The other was based on non-patent law principles of illegal contracts. Thus, the requested relief could be granted without resolving any substantive question of patent law. 

Having presented an alternate non-patent ground for the requested recoupment remedy, the asserted patent-law issue thus was not “necessarily raised.” See Inspired Development Group, LLC v. Inspired Products Group, LLC, 938 F.3d 1355, 1362–63 (Fed. Cir. 2019) (finding issue not necessarily raised where alternative ground for relief presented); NeuroRepair, 781 F.3d at 1344–45 (same). 

The Patently-O blog noted that "[t]his narrow holding allowed the court to sidestep broader questions about when patent law issues arising in arbitration contexts warrant Federal Circuit review, leaving practitioners and lower courts without clear guidance on the boundaries of Federal Circuit jurisdiction over patent-related arbitration disputes."