Bilski v. Kappos — Supreme Court Rejects Machine-or-Transformation as Exclusive Patent Eligibility Test

Background

Bernard Bilski and Rand Warsaw applied for a patent on a method of hedging risk in the energy commodities market. Their claims described a series of steps for how buyers and sellers in the energy industry could protect against price changes by entering into offsetting contracts with counterparties at fixed prices — essentially encoding a financial risk-management strategy as a series of procedural steps.

The U.S. Patent and Trademark Office rejected the application, and the Federal Circuit affirmed, applying a rigid “machine-or-transformation” test: a process claim is patent-eligible only if tied to a particular machine or apparatus, or if it transforms an article from one state into another. Bilski petitioned the Supreme Court, arguing the Federal Circuit’s test was too restrictive.

The Court’s Holding

The Supreme Court unanimously affirmed the rejection of Bilski’s claims, but the majority refused to adopt the machine-or-transformation test as the sole standard for patent eligibility. Justice Kennedy, writing for five justices, held that while the test is a “useful and important clue,” the Patent Act’s text does not limit eligible processes to those satisfying that test. Inventions that fit within the broad categories of process, machine, manufacture, or composition of matter remain potentially eligible — subject to the three judicially recognized exceptions: laws of nature, physical phenomena, and abstract ideas.

The Court held that Bilski’s risk-hedging method was simply an abstract idea — a fundamental concept in the field of commodity trading — and that the claims did no more than describe the abstract idea itself. Applying an abstract idea to a particular field of use, or breaking it into steps, does not convert it into patentable subject matter.

Key Takeaways

• The machine-or-transformation test is a useful guide but not the exclusive test for process patent eligibility under 35 U.S.C. §101.
• Abstract ideas are not patentable, even when applied to a specific economic or commercial context like energy markets.
• Business methods are not categorically excluded from patent protection, but face a high bar when they recite abstract concepts without meaningful technological implementation.
• The decision preserved flexibility but left courts without a clear successor test, setting the stage for Mayo (2012) and Alice (2014).

Why It Matters

Bilski was the Supreme Court’s first significant pronouncement on software and business method patent eligibility in the post-State Street era. By rejecting a bright-line rule while still affirming the abstract-idea bar, the Court invited the wave of §101 litigation that followed. Patent practitioners, technology companies, and financial institutions all had to grapple with an uncertain standard: if the machine-or-transformation test is not required, what is?

The answer emerged incrementally in Mayo Collaborative Services v. Prometheus Laboratories (2012) and Alice Corp. v. CLS Bank International (2014), which built on Bilski to create the two-step framework now used in every §101 analysis. Bilski’s legacy is that it kept the door open for business-method and software patents while making clear that abstract ideas belong to everyone — not just the first to apply for a patent on them.