Machine-or-transformation test

In United States patent law, the machine-or-transformation test is a test of patent eligibility under which a claim to a process qualifies for consideration if it (1) is implemented by a particular machine in a non-conventional and non-trivial manner or (2) transforms an article from one state to another.

The test was first articulated under its present form in the government's brief in Gottschalk v. Benson. In its reply brief on the merits in that case, the government said, "we submit that the cases follow such a rule—implicitly or explicitly—and that they cannot be rationalized otherwise." The court declined to adopt the proposed rule as categorical and as an exclusive test. It opined that future cases might present fact patterns calling for a different rule from that applicable to past cases, and therefore the machine-or-transformation test was just a "clue" to eligibility for a patent.

The test has been recently articulated in Bilski, but dates back to the nineteenth century. The test is articulated also in the patent-eligibility trilogy—Gottschalk v. Benson,Parker v. Flook, and Diamond v. Diehr. In the wake of the Supreme Court's opinion in Bilski v. Kappos, rejecting machine-or-transformation as the sole test of patent eligibility, and confirming that it is only a "useful clue," it is now clear that this test is only a way to measure whether the patent claim in issue preempts substantially all applications of the underlying idea or principle on which a patent is based—such preemption being a far more basic and general test of patent eligibility or ineligibility.

The Supreme Court has held that the machine-or-transformation test is not the sole test for the patent-eligibility of processes. The certiorari petition in Bilski challenged that proposition. and the Supreme Court's Bilski opinion expressly rejected the Federal Circuit's declaration that it was the exclusive test to apply; despite a dissent on the proper rationale, the court was unanimous on this point.

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